diff --git a/lib/css-tools.js b/lib/css-tools.js
index 6517892b..715f696c 100644
--- a/lib/css-tools.js
+++ b/lib/css-tools.js
@@ -1,10 +1,9 @@
 'use strict';
 
-var csstree     = require('css-tree'),
-    List        = csstree.List,
-    stable      = require('stable'),
-    specificity = require('csso/lib/restructure/prepare/specificity');
-
+var csstree = require('css-tree'),
+  List = csstree.List,
+  stable = require('stable'),
+  specificity = require('csso/lib/restructure/prepare/specificity');
 
 /**
  * Flatten a CSS AST to a selectors list.
@@ -13,39 +12,48 @@ var csstree     = require('css-tree'),
  * @return {Array} selectors
  */
 function flattenToSelectors(cssAst) {
-    var selectors = [];
+  var selectors = [];
 
-    csstree.walk(cssAst, {visit: 'Rule', enter: function(node) {
-        if (node.type !== 'Rule') {
-            return;
-        }
+  csstree.walk(cssAst, {
+    visit: 'Rule',
+    enter: function (node) {
+      if (node.type !== 'Rule') {
+        return;
+      }
 
-        var atrule = this.atrule;
-        var rule = node;
+      var atrule = this.atrule;
+      var rule = node;
 
-        node.prelude.children.each(function(selectorNode, selectorItem) {
-            var selector = {
-                item: selectorItem,
-                atrule: atrule,
-                rule: rule,
-                pseudos: []
-            };
+      node.prelude.children.each(function (selectorNode, selectorItem) {
+        var selector = {
+          item: selectorItem,
+          atrule: atrule,
+          rule: rule,
+          pseudos: [],
+        };
 
-            selectorNode.children.each(function(selectorChildNode, selectorChildItem, selectorChildList) {
-                if (selectorChildNode.type === 'PseudoClassSelector' ||
-                    selectorChildNode.type === 'PseudoElementSelector') {
-                    selector.pseudos.push({
-                        item: selectorChildItem,
-                        list: selectorChildList
-                    });
-                }
+        selectorNode.children.each(function (
+          selectorChildNode,
+          selectorChildItem,
+          selectorChildList
+        ) {
+          if (
+            selectorChildNode.type === 'PseudoClassSelector' ||
+            selectorChildNode.type === 'PseudoElementSelector'
+          ) {
+            selector.pseudos.push({
+              item: selectorChildItem,
+              list: selectorChildList,
             });
-
-            selectors.push(selector);
+          }
         });
-    }});
 
-    return selectors;
+        selectors.push(selector);
+      });
+    },
+  });
+
+  return selectors;
 }
 
 /**
@@ -56,21 +64,23 @@ function flattenToSelectors(cssAst) {
  * @return {Array} Filtered selectors that match the passed media queries
  */
 function filterByMqs(selectors, useMqs) {
-    return selectors.filter(function(selector) {
-        if (selector.atrule === null) {
-            return ~useMqs.indexOf('');
-        }
+  return selectors.filter(function (selector) {
+    if (selector.atrule === null) {
+      return ~useMqs.indexOf('');
+    }
 
-        var mqName = selector.atrule.name;
-        var mqStr = mqName;
-        if (selector.atrule.expression &&
-            selector.atrule.expression.children.first().type === 'MediaQueryList') {
-            var mqExpr = csstree.generate(selector.atrule.expression);
-            mqStr = [mqName, mqExpr].join(' ');
-        }
+    var mqName = selector.atrule.name;
+    var mqStr = mqName;
+    if (
+      selector.atrule.expression &&
+      selector.atrule.expression.children.first().type === 'MediaQueryList'
+    ) {
+      var mqExpr = csstree.generate(selector.atrule.expression);
+      mqStr = [mqName, mqExpr].join(' ');
+    }
 
-        return ~useMqs.indexOf(mqStr);
-    });
+    return ~useMqs.indexOf(mqStr);
+  });
 }
 
 /**
@@ -81,15 +91,17 @@ function filterByMqs(selectors, useMqs) {
  * @return {Array} Filtered selectors that match the passed pseudo-elements and/or -classes
  */
 function filterByPseudos(selectors, usePseudos) {
-    return selectors.filter(function(selector) {
-        var pseudoSelectorsStr = csstree.generate({
-            type: 'Selector',
-            children: new List().fromArray(selector.pseudos.map(function(pseudo) {
-                return pseudo.item.data;
-            }))
-        });
-        return ~usePseudos.indexOf(pseudoSelectorsStr);
+  return selectors.filter(function (selector) {
+    var pseudoSelectorsStr = csstree.generate({
+      type: 'Selector',
+      children: new List().fromArray(
+        selector.pseudos.map(function (pseudo) {
+          return pseudo.item.data;
+        })
+      ),
     });
+    return ~usePseudos.indexOf(pseudoSelectorsStr);
+  });
 }
 
 /**
@@ -99,14 +111,13 @@ function filterByPseudos(selectors, usePseudos) {
  * @return {Array} Selectors without pseudo-elements and/or -classes
  */
 function cleanPseudos(selectors) {
-    selectors.forEach(function(selector) {
-        selector.pseudos.forEach(function(pseudo) {
-            pseudo.list.remove(pseudo.item);
-        });
+  selectors.forEach(function (selector) {
+    selector.pseudos.forEach(function (pseudo) {
+      pseudo.list.remove(pseudo.item);
     });
+  });
 }
 
-
 /**
  * Compares two selector specificities.
  * extracted from https://github.com/keeganstreet/specificity/blob/master/specificity.js#L211
@@ -116,18 +127,17 @@ function cleanPseudos(selectors) {
  * @return {Number} Score of selector specificity A compared to selector specificity B
  */
 function compareSpecificity(aSpecificity, bSpecificity) {
-    for (var i = 0; i < 4; i += 1) {
-        if (aSpecificity[i] < bSpecificity[i]) {
-            return -1;
-        } else if (aSpecificity[i] > bSpecificity[i]) {
-            return 1;
-        }
+  for (var i = 0; i < 4; i += 1) {
+    if (aSpecificity[i] < bSpecificity[i]) {
+      return -1;
+    } else if (aSpecificity[i] > bSpecificity[i]) {
+      return 1;
     }
+  }
 
-    return 0;
+  return 0;
 }
 
-
 /**
  * Compare two simple selectors.
  *
@@ -136,16 +146,15 @@ function compareSpecificity(aSpecificity, bSpecificity) {
  * @return {Number} Score of selector A compared to selector B
  */
 function compareSimpleSelectorNode(aSimpleSelectorNode, bSimpleSelectorNode) {
-    var aSpecificity = specificity(aSimpleSelectorNode),
-        bSpecificity = specificity(bSimpleSelectorNode);
-    return compareSpecificity(aSpecificity, bSpecificity);
+  var aSpecificity = specificity(aSimpleSelectorNode),
+    bSpecificity = specificity(bSimpleSelectorNode);
+  return compareSpecificity(aSpecificity, bSpecificity);
 }
 
 function _bySelectorSpecificity(selectorA, selectorB) {
-    return compareSimpleSelectorNode(selectorA.item.data, selectorB.item.data);
+  return compareSimpleSelectorNode(selectorA.item.data, selectorB.item.data);
 }
 
-
 /**
  * Sort selectors stably by their specificity.
  *
@@ -153,10 +162,9 @@ function _bySelectorSpecificity(selectorA, selectorB) {
  * @return {Array} Stable sorted selectors
  */
 function sortSelectors(selectors) {
-    return stable(selectors, _bySelectorSpecificity);
+  return stable(selectors, _bySelectorSpecificity);
 }
 
-
 /**
  * Convert a css-tree AST style declaration to CSSStyleDeclaration property.
  *
@@ -164,17 +172,16 @@ function sortSelectors(selectors) {
  * @return {Object} CSSStyleDeclaration property
  */
 function csstreeToStyleDeclaration(declaration) {
-    var propertyName = declaration.property,
-        propertyValue = csstree.generate(declaration.value),
-        propertyPriority = (declaration.important ? 'important' : '');
-    return {
-        name: propertyName,
-        value: propertyValue,
-        priority: propertyPriority
-    };
+  var propertyName = declaration.property,
+    propertyValue = csstree.generate(declaration.value),
+    propertyPriority = declaration.important ? 'important' : '';
+  return {
+    name: propertyName,
+    value: propertyValue,
+    priority: propertyPriority,
+  };
 }
 
-
 /**
  * Gets the CSS string of a style element
  *
@@ -182,7 +189,7 @@ function csstreeToStyleDeclaration(declaration) {
  * @return {String|Array} CSS string or empty array if no styles are set
  */
 function getCssStr(elem) {
-    return elem.content[0].text || elem.content[0].cdata || [];
+  return elem.content[0].text || elem.content[0].cdata || [];
 }
 
 /**
@@ -193,18 +200,17 @@ function getCssStr(elem) {
  * @return {Object} reference to field with CSS
  */
 function setCssStr(elem, css) {
-    // in case of cdata field
-    if(elem.content[0].cdata) {
-        elem.content[0].cdata = css;
-        return elem.content[0].cdata;
-    }
+  // in case of cdata field
+  if (elem.content[0].cdata) {
+    elem.content[0].cdata = css;
+    return elem.content[0].cdata;
+  }
 
-    // in case of text field + if nothing was set yet
-    elem.content[0].text  = css;
-    return elem.content[0].text;
+  // in case of text field + if nothing was set yet
+  elem.content[0].text = css;
+  return elem.content[0].text;
 }
 
-
 module.exports.flattenToSelectors = flattenToSelectors;
 
 module.exports.filterByMqs = filterByMqs;
diff --git a/lib/svgo-node.js b/lib/svgo-node.js
index 71f973b4..b7e26a2c 100644
--- a/lib/svgo-node.js
+++ b/lib/svgo-node.js
@@ -8,7 +8,7 @@ const {
   createContentItem,
 } = require('./svgo.js');
 
-const importConfig = async configFile => {
+const importConfig = async (configFile) => {
   const config = require(configFile);
   if (config == null || typeof config !== 'object' || Array.isArray(config)) {
     throw Error(`Invalid config file "${configFile}"`);
@@ -23,7 +23,7 @@ const isFile = async (file) => {
   } catch {
     return false;
   }
-}
+};
 
 const loadConfig = async (configFile, cwd = process.cwd()) => {
   if (configFile != null) {
@@ -36,7 +36,7 @@ const loadConfig = async (configFile, cwd = process.cwd()) => {
   let dir = cwd;
   // eslint-disable-next-line no-constant-condition
   while (true) {
-    const file = path.join(dir, "svgo.config.js");
+    const file = path.join(dir, 'svgo.config.js');
     if (await isFile(file)) {
       return await importConfig(file);
     }
diff --git a/lib/svgo.js b/lib/svgo.js
index b037d90c..e18de1b2 100755
--- a/lib/svgo.js
+++ b/lib/svgo.js
@@ -13,7 +13,7 @@
 const {
   defaultPlugins,
   resolvePluginConfig,
-  extendDefaultPlugins
+  extendDefaultPlugins,
 } = require('./svgo/config.js');
 const svg2js = require('./svgo/svg2js.js');
 const js2svg = require('./svgo/js2svg.js');
@@ -28,12 +28,12 @@ const optimize = (input, config) => {
     config = {};
   }
   if (typeof config !== 'object') {
-    throw Error('Config should be an object')
+    throw Error('Config should be an object');
   }
   const maxPassCount = config.multipass ? 10 : 1;
   let prevResultSize = Number.POSITIVE_INFINITY;
   let svgjs = null;
-  const info = {}
+  const info = {};
   if (config.path != null) {
     info.path = config.path;
   }
@@ -48,9 +48,13 @@ const optimize = (input, config) => {
     }
     const plugins = config.plugins || defaultPlugins;
     if (Array.isArray(plugins) === false) {
-      throw Error('Invalid plugins list. Provided \'plugins\' in config should be an array.');
+      throw Error(
+        "Invalid plugins list. Provided 'plugins' in config should be an array."
+      );
     }
-    const resolvedPlugins = plugins.map(plugin => resolvePluginConfig(plugin, config))
+    const resolvedPlugins = plugins.map((plugin) =>
+      resolvePluginConfig(plugin, config)
+    );
     svgjs = invokePlugins(svgjs, info, resolvedPlugins);
     svgjs = js2svg(svgjs, config.js2svg);
     if (svgjs.error) {
@@ -58,7 +62,7 @@ const optimize = (input, config) => {
     }
     if (svgjs.data.length < prevResultSize) {
       input = svgjs.data;
-      prevResultSize = svgjs.data.length
+      prevResultSize = svgjs.data.length;
     } else {
       if (config.datauri) {
         svgjs.data = encodeSVGDatauri(svgjs.data, config.datauri);
diff --git a/lib/svgo/coa.js b/lib/svgo/coa.js
index 4f605e8b..091f4348 100644
--- a/lib/svgo/coa.js
+++ b/lib/svgo/coa.js
@@ -14,182 +14,228 @@ const regSVGFile = /\.svg$/i;
  * @param {string} path
  */
 function checkIsDir(path) {
-    try {
-        return FS.lstatSync(path).isDirectory();
-    } catch(e) {
-        return false;
-    }
+  try {
+    return FS.lstatSync(path).isDirectory();
+  } catch (e) {
+    return false;
+  }
 }
 
 module.exports = function makeProgram(program) {
-    program
-        .name(PKG.name)
-        .description(PKG.description, {
-            INPUT: 'Alias to --input'
-        })
-        .version(PKG.version, '-v, --version')
-        .arguments('[INPUT...]')
-        .option('-i, --input <INPUT...>', 'Input files, "-" for STDIN')
-        .option('-s, --string <STRING>', 'Input SVG data string')
-        .option('-f, --folder <FOLDER>', 'Input folder, optimize and rewrite all *.svg files')
-        .option('-o, --output <OUTPUT...>', 'Output file or folder (by default the same as the input), "-" for STDOUT')
-        .option('-p, --precision <INTEGER>', 'Set number of digits in the fractional part, overrides plugins params')
-        .option('--config <CONFIG>', 'Custom config file, only .js is supported')
-        .option('--datauri <FORMAT>', 'Output as Data URI string (base64), URI encoded (enc) or unencoded (unenc)')
-        .option('--multipass', 'Pass over SVGs multiple times to ensure all optimizations are applied')
-        .option('--pretty', 'Make SVG pretty printed')
-        .option('--indent <INTEGER>', 'Indent number when pretty printing SVGs')
-        .option('-r, --recursive', 'Use with \'-f\'. Optimizes *.svg files in folders recursively.')
-        .option('-q, --quiet', 'Only output error messages, not regular status messages')
-        .option('--show-plugins', 'Show available plugins and exit')
-        .action(action);
-}
+  program
+    .name(PKG.name)
+    .description(PKG.description, {
+      INPUT: 'Alias to --input',
+    })
+    .version(PKG.version, '-v, --version')
+    .arguments('[INPUT...]')
+    .option('-i, --input <INPUT...>', 'Input files, "-" for STDIN')
+    .option('-s, --string <STRING>', 'Input SVG data string')
+    .option(
+      '-f, --folder <FOLDER>',
+      'Input folder, optimize and rewrite all *.svg files'
+    )
+    .option(
+      '-o, --output <OUTPUT...>',
+      'Output file or folder (by default the same as the input), "-" for STDOUT'
+    )
+    .option(
+      '-p, --precision <INTEGER>',
+      'Set number of digits in the fractional part, overrides plugins params'
+    )
+    .option('--config <CONFIG>', 'Custom config file, only .js is supported')
+    .option(
+      '--datauri <FORMAT>',
+      'Output as Data URI string (base64), URI encoded (enc) or unencoded (unenc)'
+    )
+    .option(
+      '--multipass',
+      'Pass over SVGs multiple times to ensure all optimizations are applied'
+    )
+    .option('--pretty', 'Make SVG pretty printed')
+    .option('--indent <INTEGER>', 'Indent number when pretty printing SVGs')
+    .option(
+      '-r, --recursive',
+      "Use with '-f'. Optimizes *.svg files in folders recursively."
+    )
+    .option(
+      '-q, --quiet',
+      'Only output error messages, not regular status messages'
+    )
+    .option('--show-plugins', 'Show available plugins and exit')
+    .action(action);
+};
 
 async function action(args, opts, command) {
-    var input = opts.input || args;
-    var output = opts.output;
-    var config = {}
+  var input = opts.input || args;
+  var output = opts.output;
+  var config = {};
 
-    if (opts.precision != null) {
-        const number = Number.parseInt(opts.precision, 0);
-        if (Number.isNaN(number)) {
-            console.error("error: option '-p, --precision' argument must be an integer number");
-            process.exit(1)
-        } else {
-            opts.precision = number;
-        }
+  if (opts.precision != null) {
+    const number = Number.parseInt(opts.precision, 0);
+    if (Number.isNaN(number)) {
+      console.error(
+        "error: option '-p, --precision' argument must be an integer number"
+      );
+      process.exit(1);
+    } else {
+      opts.precision = number;
     }
+  }
 
-    if (opts.datauri != null) {
-        if (opts.datauri !== 'base64' && opts.datauri !== 'enc' && opts.datauri !== 'unenc') {
-          console.error("error: option '--datauri' must have one of the following values: 'base64', 'enc' or 'unenc'")
-          process.exit(1)
-        }
-    }
-
-    if (opts.indent != null) {
-        const number = Number.parseInt(opts.indent, 0);
-        if (Number.isNaN(number)) {
-            console.error("error: option '--indent' argument must be an integer number");
-            process.exit(1);
-        } else {
-            opts.indent = number;
-        }
-    }
-
-    // --show-plugins
-    if (opts.showPlugins) {
-        showAvailablePlugins();
-        return;
-    }
-
-    // w/o anything
+  if (opts.datauri != null) {
     if (
-        (input.length === 0 || input[0] === '-') &&
-        !opts.string &&
-        !opts.stdin &&
-        !opts.folder &&
-        process.stdin.isTTY === true
+      opts.datauri !== 'base64' &&
+      opts.datauri !== 'enc' &&
+      opts.datauri !== 'unenc'
     ) {
-      return command.help();
+      console.error(
+        "error: option '--datauri' must have one of the following values: 'base64', 'enc' or 'unenc'"
+      );
+      process.exit(1);
     }
+  }
 
-    if (typeof process == 'object' && process.versions && process.versions.node && PKG && PKG.engines.node) {
-        var nodeVersion = String(PKG.engines.node).match(/\d*(\.\d+)*/)[0];
-        if (parseFloat(process.versions.node) < parseFloat(nodeVersion)) {
-            throw Error(`${PKG.name} requires Node.js version ${nodeVersion} or higher.`);
+  if (opts.indent != null) {
+    const number = Number.parseInt(opts.indent, 0);
+    if (Number.isNaN(number)) {
+      console.error(
+        "error: option '--indent' argument must be an integer number"
+      );
+      process.exit(1);
+    } else {
+      opts.indent = number;
+    }
+  }
+
+  // --show-plugins
+  if (opts.showPlugins) {
+    showAvailablePlugins();
+    return;
+  }
+
+  // w/o anything
+  if (
+    (input.length === 0 || input[0] === '-') &&
+    !opts.string &&
+    !opts.stdin &&
+    !opts.folder &&
+    process.stdin.isTTY === true
+  ) {
+    return command.help();
+  }
+
+  if (
+    typeof process == 'object' &&
+    process.versions &&
+    process.versions.node &&
+    PKG &&
+    PKG.engines.node
+  ) {
+    var nodeVersion = String(PKG.engines.node).match(/\d*(\.\d+)*/)[0];
+    if (parseFloat(process.versions.node) < parseFloat(nodeVersion)) {
+      throw Error(
+        `${PKG.name} requires Node.js version ${nodeVersion} or higher.`
+      );
+    }
+  }
+
+  // --config
+  const loadedConfig = await loadConfig(opts.config);
+  if (loadedConfig != null) {
+    config = loadedConfig;
+  }
+
+  // --quiet
+  if (opts.quiet) {
+    config.quiet = opts.quiet;
+  }
+
+  // --recursive
+  if (opts.recursive) {
+    config.recursive = opts.recursive;
+  }
+
+  // --precision
+  if (opts.precision != null) {
+    var precision = Math.min(Math.max(0, opts.precision), 20);
+    config.floatPrecision = precision;
+  }
+
+  // --multipass
+  if (opts.multipass) {
+    config.multipass = true;
+  }
+
+  // --pretty
+  if (opts.pretty) {
+    config.js2svg = config.js2svg || {};
+    config.js2svg.pretty = true;
+    if (opts.indent != null) {
+      config.js2svg.indent = opts.indent;
+    }
+  }
+
+  // --output
+  if (output) {
+    if (input.length && input[0] != '-') {
+      if (output.length == 1 && checkIsDir(output[0])) {
+        var dir = output[0];
+        for (var i = 0; i < input.length; i++) {
+          output[i] = checkIsDir(input[i])
+            ? input[i]
+            : PATH.resolve(dir, PATH.basename(input[i]));
         }
+      } else if (output.length < input.length) {
+        output = output.concat(input.slice(output.length));
+      }
     }
+  } else if (input.length) {
+    output = input;
+  } else if (opts.string) {
+    output = '-';
+  }
 
-    // --config
-    const loadedConfig = await loadConfig(opts.config);
-    if (loadedConfig != null) {
-      config = loadedConfig;
+  if (opts.datauri) {
+    config.datauri = opts.datauri;
+  }
+
+  // --folder
+  if (opts.folder) {
+    var ouputFolder = (output && output[0]) || opts.folder;
+    await optimizeFolder(config, opts.folder, ouputFolder);
+  }
+
+  // --input
+  if (input.length !== 0) {
+    // STDIN
+    if (input[0] === '-') {
+      return new Promise((resolve, reject) => {
+        var data = '',
+          file = output[0];
+
+        process.stdin
+          .on('data', (chunk) => (data += chunk))
+          .once('end', () =>
+            processSVGData(config, { input: 'string' }, data, file).then(
+              resolve,
+              reject
+            )
+          );
+      });
+      // file
+    } else {
+      await Promise.all(
+        input.map((file, n) => optimizeFile(config, file, output[n]))
+      );
     }
 
-    // --quiet
-    if (opts.quiet) {
-        config.quiet = opts.quiet;
-    }
-
-    // --recursive
-    if (opts.recursive) {
-        config.recursive = opts.recursive;
-    }
-
-    // --precision
-    if (opts.precision != null) {
-        var precision = Math.min(Math.max(0, opts.precision), 20);
-        config.floatPrecision = precision;
-    }
-
-    // --multipass
-    if (opts.multipass) {
-        config.multipass = true;
-    }
-
-    // --pretty
-    if (opts.pretty) {
-        config.js2svg = config.js2svg || {};
-        config.js2svg.pretty = true;
-        if (opts.indent != null) {
-            config.js2svg.indent = opts.indent;
-        }
-    }
-
-    // --output
-    if (output) {
-        if (input.length && input[0] != '-') {
-            if (output.length == 1 && checkIsDir(output[0])) {
-                var dir = output[0];
-                for (var i = 0; i < input.length; i++) {
-                    output[i] = checkIsDir(input[i]) ? input[i] : PATH.resolve(dir, PATH.basename(input[i]));
-                }
-            } else if (output.length < input.length) {
-                output = output.concat(input.slice(output.length));
-            }
-        }
-    } else if (input.length) {
-        output = input;
-    } else if (opts.string) {
-        output = '-';
-    }
-
-    if (opts.datauri) {
-        config.datauri = opts.datauri;
-    }
-
-    // --folder
-    if (opts.folder) {
-        var ouputFolder = output && output[0] || opts.folder;
-        await optimizeFolder(config, opts.folder, ouputFolder);
-    }
-
-    // --input
-    if (input.length !== 0) {
-        // STDIN
-        if (input[0] === '-') {
-            return new Promise((resolve, reject) => {
-                var data = '',
-                    file = output[0];
-
-                process.stdin
-                    .on('data', chunk => data += chunk)
-                    .once('end', () => processSVGData(config, {input: 'string'}, data, file).then(resolve, reject));
-            });
-        // file
-        } else {
-            await Promise.all(
-              input.map((file, n) => optimizeFile(config, file, output[n]))
-            );
-        }
-
     // --string
-    } else if (opts.string) {
-        var data = decodeSVGDatauri(opts.string);
+  } else if (opts.string) {
+    var data = decodeSVGDatauri(opts.string);
 
-        return processSVGData(config, {input: 'string'}, data, output[0]);
-    }
+    return processSVGData(config, { input: 'string' }, data, output[0]);
+  }
 }
 
 /**
@@ -200,10 +246,12 @@ async function action(args, opts, command) {
  * @return {Promise}
  */
 function optimizeFolder(config, dir, output) {
-    if (!config.quiet) {
-        console.log(`Processing directory '${dir}':\n`);
-    }
-    return FS.promises.readdir(dir).then(files => processDirectory(config, dir, files, output));
+  if (!config.quiet) {
+    console.log(`Processing directory '${dir}':\n`);
+  }
+  return FS.promises
+    .readdir(dir)
+    .then((files) => processDirectory(config, dir, files, output));
 }
 
 /**
@@ -215,12 +263,22 @@ function optimizeFolder(config, dir, output) {
  * @return {Promise}
  */
 function processDirectory(config, dir, files, output) {
-    // take only *.svg files, recursively if necessary
-    var svgFilesDescriptions = getFilesDescriptions(config, dir, files, output);
+  // take only *.svg files, recursively if necessary
+  var svgFilesDescriptions = getFilesDescriptions(config, dir, files, output);
 
-    return svgFilesDescriptions.length ?
-        Promise.all(svgFilesDescriptions.map(fileDescription => optimizeFile(config, fileDescription.inputPath, fileDescription.outputPath))) :
-        Promise.reject(new Error(`No SVG files have been found in '${dir}' directory.`));
+  return svgFilesDescriptions.length
+    ? Promise.all(
+        svgFilesDescriptions.map((fileDescription) =>
+          optimizeFile(
+            config,
+            fileDescription.inputPath,
+            fileDescription.outputPath
+          )
+        )
+      )
+    : Promise.reject(
+        new Error(`No SVG files have been found in '${dir}' directory.`)
+      );
 }
 
 /**
@@ -232,27 +290,32 @@ function processDirectory(config, dir, files, output) {
  * @return {Array}
  */
 function getFilesDescriptions(config, dir, files, output) {
-    const filesInThisFolder = files
-        .filter(name => regSVGFile.test(name))
-        .map(name => ({
-            inputPath: PATH.resolve(dir, name),
-            outputPath: PATH.resolve(output, name),
-        }));
+  const filesInThisFolder = files
+    .filter((name) => regSVGFile.test(name))
+    .map((name) => ({
+      inputPath: PATH.resolve(dir, name),
+      outputPath: PATH.resolve(output, name),
+    }));
 
-    return config.recursive ?
-        [].concat(
-            filesInThisFolder,
-            files
-                .filter(name => checkIsDir(PATH.resolve(dir, name)))
-                .map(subFolderName => {
-                    const subFolderPath = PATH.resolve(dir, subFolderName);
-                    const subFolderFiles = FS.readdirSync(subFolderPath);
-                    const subFolderOutput = PATH.resolve(output, subFolderName);
-                    return getFilesDescriptions(config, subFolderPath, subFolderFiles, subFolderOutput);
-                })
-                .reduce((a, b) => [].concat(a, b), [])
-        ) :
-        filesInThisFolder;
+  return config.recursive
+    ? [].concat(
+        filesInThisFolder,
+        files
+          .filter((name) => checkIsDir(PATH.resolve(dir, name)))
+          .map((subFolderName) => {
+            const subFolderPath = PATH.resolve(dir, subFolderName);
+            const subFolderFiles = FS.readdirSync(subFolderPath);
+            const subFolderOutput = PATH.resolve(output, subFolderName);
+            return getFilesDescriptions(
+              config,
+              subFolderPath,
+              subFolderFiles,
+              subFolderOutput
+            );
+          })
+          .reduce((a, b) => [].concat(a, b), [])
+      )
+    : filesInThisFolder;
 }
 
 /**
@@ -263,10 +326,11 @@ function getFilesDescriptions(config, dir, files, output) {
  * @return {Promise}
  */
 function optimizeFile(config, file, output) {
-    return FS.promises.readFile(file, 'utf8').then(
-        data => processSVGData(config, {input: 'file', path: file}, data, output, file),
-        error => checkOptimizeFileError(config, file, output, error)
-    );
+  return FS.promises.readFile(file, 'utf8').then(
+    (data) =>
+      processSVGData(config, { input: 'file', path: file }, data, output, file),
+    (error) => checkOptimizeFileError(config, file, output, error)
+  );
 }
 
 /**
@@ -278,33 +342,42 @@ function optimizeFile(config, file, output) {
  * @return {Promise}
  */
 function processSVGData(config, info, data, output, input) {
-    var startTime = Date.now(),
-        prevFileSize = Buffer.byteLength(data, 'utf8');
+  var startTime = Date.now(),
+    prevFileSize = Buffer.byteLength(data, 'utf8');
 
-    const result = optimize(data, { ...config, ...info });
-    if (result.error) {
-      let message = result.error;
-      if (result.path != null) {
-        message += `\nFile: ${result.path}`
-      }
-      throw Error(message)
+  const result = optimize(data, { ...config, ...info });
+  if (result.error) {
+    let message = result.error;
+    if (result.path != null) {
+      message += `\nFile: ${result.path}`;
     }
-    if (config.datauri) {
-        result.data = encodeSVGDatauri(result.data, config.datauri);
-    }
-    var resultFileSize = Buffer.byteLength(result.data, 'utf8'),
-        processingTime = Date.now() - startTime;
+    throw Error(message);
+  }
+  if (config.datauri) {
+    result.data = encodeSVGDatauri(result.data, config.datauri);
+  }
+  var resultFileSize = Buffer.byteLength(result.data, 'utf8'),
+    processingTime = Date.now() - startTime;
 
-    return writeOutput(input, output, result.data).then(function() {
-        if (!config.quiet && output != '-') {
-            if (input) {
-                console.log(`\n${PATH.basename(input)}:`);
-            }
-            printTimeInfo(processingTime);
-            printProfitInfo(prevFileSize, resultFileSize);
+  return writeOutput(input, output, result.data).then(
+    function () {
+      if (!config.quiet && output != '-') {
+        if (input) {
+          console.log(`\n${PATH.basename(input)}:`);
         }
+        printTimeInfo(processingTime);
+        printProfitInfo(prevFileSize, resultFileSize);
+      }
     },
-    error => Promise.reject(new Error(error.code === 'ENOTDIR' ? `Error: output '${output}' is not a directory.` : error)));
+    (error) =>
+      Promise.reject(
+        new Error(
+          error.code === 'ENOTDIR'
+            ? `Error: output '${output}' is not a directory.`
+            : error
+        )
+      )
+  );
 }
 
 /**
@@ -315,23 +388,24 @@ function processSVGData(config, info, data, output, input) {
  * @return {Promise}
  */
 function writeOutput(input, output, data) {
-    if (output == '-') {
-        console.log(data);
-        return Promise.resolve();
-    }
+  if (output == '-') {
+    console.log(data);
+    return Promise.resolve();
+  }
 
-    FS.mkdirSync(PATH.dirname(output), { recursive: true });
+  FS.mkdirSync(PATH.dirname(output), { recursive: true });
 
-    return FS.promises.writeFile(output, data, 'utf8').catch(error => checkWriteFileError(input, output, data, error));
+  return FS.promises
+    .writeFile(output, data, 'utf8')
+    .catch((error) => checkWriteFileError(input, output, data, error));
 }
 
-
 /**
  * Write a time taken by optimization.
  * @param {number} time time in milliseconds.
  */
 function printTimeInfo(time) {
-    console.log(`Done in ${time} ms!`);
+  console.log(`Done in ${time} ms!`);
 }
 
 /**
@@ -340,14 +414,17 @@ function printTimeInfo(time) {
  * @param {number} outBytes size after optimization.
  */
 function printProfitInfo(inBytes, outBytes) {
-    var profitPercents = 100 - outBytes * 100 / inBytes;
+  var profitPercents = 100 - (outBytes * 100) / inBytes;
 
-    console.log(
-        (Math.round((inBytes / 1024) * 1000) / 1000) + ' KiB' +
-        (profitPercents < 0 ? ' + ' : ' - ') +
-        chalk.green(Math.abs((Math.round(profitPercents * 10) / 10)) + '%') + ' = ' +
-        (Math.round((outBytes / 1024) * 1000) / 1000) + ' KiB'
-    );
+  console.log(
+    Math.round((inBytes / 1024) * 1000) / 1000 +
+      ' KiB' +
+      (profitPercents < 0 ? ' + ' : ' - ') +
+      chalk.green(Math.abs(Math.round(profitPercents * 10) / 10) + '%') +
+      ' = ' +
+      Math.round((outBytes / 1024) * 1000) / 1000 +
+      ' KiB'
+  );
 }
 
 /**
@@ -359,12 +436,14 @@ function printProfitInfo(inBytes, outBytes) {
  * @return {Promise}
  */
 function checkOptimizeFileError(config, input, output, error) {
-    if (error.code == 'EISDIR') {
-        return optimizeFolder(config, input, output);
-    } else if (error.code == 'ENOENT') {
-        return Promise.reject(new Error(`Error: no such file or directory '${error.path}'.`));
-    }
-    return Promise.reject(error);
+  if (error.code == 'EISDIR') {
+    return optimizeFolder(config, input, output);
+  } else if (error.code == 'ENOENT') {
+    return Promise.reject(
+      new Error(`Error: no such file or directory '${error.path}'.`)
+    );
+  }
+  return Promise.reject(error);
 }
 
 /**
@@ -376,22 +455,26 @@ function checkOptimizeFileError(config, input, output, error) {
  * @return {Promise}
  */
 function checkWriteFileError(input, output, data, error) {
-    if (error.code == 'EISDIR' && input) {
-        return FS.promises.writeFile(PATH.resolve(output, PATH.basename(input)), data, 'utf8');
-    } else {
-        return Promise.reject(error);
-    }
+  if (error.code == 'EISDIR' && input) {
+    return FS.promises.writeFile(
+      PATH.resolve(output, PATH.basename(input)),
+      data,
+      'utf8'
+    );
+  } else {
+    return Promise.reject(error);
+  }
 }
 
 /**
  * Show list of available plugins with short description.
  */
 function showAvailablePlugins() {
-    const list = Object.entries(pluginsMap)
-      .sort(([a], [b]) => a.localeCompare(b))
-      .map(([name, plugin]) => ` [ ${chalk.green(name)} ] ${plugin.description}`)
-      .join('\n');
-    console.log('Currently available plugins:\n' + list);
+  const list = Object.entries(pluginsMap)
+    .sort(([a], [b]) => a.localeCompare(b))
+    .map(([name, plugin]) => ` [ ${chalk.green(name)} ] ${plugin.description}`)
+    .join('\n');
+  console.log('Currently available plugins:\n' + list);
 }
 
 module.exports.checkIsDir = checkIsDir;
diff --git a/lib/svgo/config.js b/lib/svgo/config.js
index 41de417f..790c2de2 100644
--- a/lib/svgo/config.js
+++ b/lib/svgo/config.js
@@ -53,11 +53,14 @@ const pluginsOrder = [
   'removeOffCanvasPaths',
   'reusePaths',
 ];
-const defaultPlugins = pluginsOrder.filter(name => pluginsMap[name].active);
+const defaultPlugins = pluginsOrder.filter((name) => pluginsMap[name].active);
 exports.defaultPlugins = defaultPlugins;
 
 const extendDefaultPlugins = (plugins) => {
-  const extendedPlugins = pluginsOrder.map(name => ({ name, ...pluginsMap[name] }));
+  const extendedPlugins = pluginsOrder.map((name) => ({
+    name,
+    ...pluginsMap[name],
+  }));
   for (const plugin of plugins) {
     const resolvedPlugin = resolvePluginConfig(plugin, {});
     const index = pluginsOrder.indexOf(resolvedPlugin.name);
@@ -68,7 +71,7 @@ const extendDefaultPlugins = (plugins) => {
     }
   }
   return extendedPlugins;
-}
+};
 exports.extendDefaultPlugins = extendDefaultPlugins;
 
 const resolvePluginConfig = (plugin, config) => {
@@ -86,7 +89,7 @@ const resolvePluginConfig = (plugin, config) => {
       ...pluginConfig,
       name: plugin,
       active: true,
-      params: { ...pluginConfig.params, ...configParams }
+      params: { ...pluginConfig.params, ...configParams },
     };
   }
   if (typeof plugin === 'object' && plugin != null) {
@@ -98,7 +101,7 @@ const resolvePluginConfig = (plugin, config) => {
       return {
         active: true,
         ...plugin,
-        params: { configParams, ...plugin.params }
+        params: { configParams, ...plugin.params },
       };
     } else {
       // resolve builtin plugin specified as object without implementation
@@ -110,7 +113,7 @@ const resolvePluginConfig = (plugin, config) => {
         ...pluginConfig,
         active: true,
         ...plugin,
-        params: { ...pluginConfig.params, ...configParams, ...plugin.params }
+        params: { ...pluginConfig.params, ...configParams, ...plugin.params },
       };
     }
   }
diff --git a/lib/svgo/css-class-list.js b/lib/svgo/css-class-list.js
index 263c5069..7cf38b5a 100644
--- a/lib/svgo/css-class-list.js
+++ b/lib/svgo/css-class-list.js
@@ -1,10 +1,10 @@
 'use strict';
 
-var CSSClassList = function(node) {
-    this.parentNode = node;
-    this.classNames = new Set();
-    this.classAttr = null;
-    //this.classValue = null;
+var CSSClassList = function (node) {
+  this.parentNode = node;
+  this.classNames = new Set();
+  this.classAttr = null;
+  //this.classValue = null;
 };
 
 /**
@@ -12,121 +12,115 @@ var CSSClassList = function(node) {
  *
  * @param parentNode the parentNode to assign to the cloned result
  */
-CSSClassList.prototype.clone = function(parentNode) {
-    var node = this;
-    var nodeData = {};
+CSSClassList.prototype.clone = function (parentNode) {
+  var node = this;
+  var nodeData = {};
 
-    Object.keys(node).forEach(function(key) {
-        if (key !== 'parentNode') {
-            nodeData[key] = node[key];
-        }
-    });
+  Object.keys(node).forEach(function (key) {
+    if (key !== 'parentNode') {
+      nodeData[key] = node[key];
+    }
+  });
 
-    // Deep-clone node data.
-    nodeData = JSON.parse(JSON.stringify(nodeData));
+  // Deep-clone node data.
+  nodeData = JSON.parse(JSON.stringify(nodeData));
 
-    var clone = new CSSClassList(parentNode);
-   Object.assign(clone, nodeData);
-    return clone;
+  var clone = new CSSClassList(parentNode);
+  Object.assign(clone, nodeData);
+  return clone;
 };
 
-CSSClassList.prototype.hasClass = function() {
-    this.classAttr = { // empty class attr
-        'name': 'class',
-        'value': null
-    };
+CSSClassList.prototype.hasClass = function () {
+  this.classAttr = {
+    // empty class attr
+    name: 'class',
+    value: null,
+  };
 
-    this.addClassHandler();
+  this.addClassHandler();
 };
 
-
 // attr.class
 
-CSSClassList.prototype.addClassHandler = function() {
+CSSClassList.prototype.addClassHandler = function () {
+  Object.defineProperty(this.parentNode.attrs, 'class', {
+    get: this.getClassAttr.bind(this),
+    set: this.setClassAttr.bind(this),
+    enumerable: true,
+    configurable: true,
+  });
 
-    Object.defineProperty(this.parentNode.attrs, 'class', {
-        get: this.getClassAttr.bind(this),
-        set: this.setClassAttr.bind(this),
-        enumerable: true,
-        configurable: true
-    });
-
-    this.addClassValueHandler();
+  this.addClassValueHandler();
 };
 
 // attr.class.value
 
-CSSClassList.prototype.addClassValueHandler = function() {
-
-    Object.defineProperty(this.classAttr, 'value', {
-        get: this.getClassValue.bind(this),
-        set: this.setClassValue.bind(this),
-        enumerable: true,
-        configurable: true
-    });
+CSSClassList.prototype.addClassValueHandler = function () {
+  Object.defineProperty(this.classAttr, 'value', {
+    get: this.getClassValue.bind(this),
+    set: this.setClassValue.bind(this),
+    enumerable: true,
+    configurable: true,
+  });
 };
 
-CSSClassList.prototype.getClassAttr = function() {
-    return this.classAttr;
+CSSClassList.prototype.getClassAttr = function () {
+  return this.classAttr;
 };
 
-CSSClassList.prototype.setClassAttr = function(newClassAttr) {
-    this.setClassValue(newClassAttr.value); // must before applying value handler!
+CSSClassList.prototype.setClassAttr = function (newClassAttr) {
+  this.setClassValue(newClassAttr.value); // must before applying value handler!
 
-    this.classAttr = newClassAttr;
-    this.addClassValueHandler();
+  this.classAttr = newClassAttr;
+  this.addClassValueHandler();
 };
 
-CSSClassList.prototype.getClassValue = function() {
-    var arrClassNames = Array.from(this.classNames);
-    return arrClassNames.join(' ');
+CSSClassList.prototype.getClassValue = function () {
+  var arrClassNames = Array.from(this.classNames);
+  return arrClassNames.join(' ');
 };
 
-CSSClassList.prototype.setClassValue = function(newValue) {
-    if(typeof newValue === 'undefined') {
-      this.classNames.clear();
-      return;
-    }
-    var arrClassNames = newValue.split(' ');
-    this.classNames = new Set(arrClassNames);
+CSSClassList.prototype.setClassValue = function (newValue) {
+  if (typeof newValue === 'undefined') {
+    this.classNames.clear();
+    return;
+  }
+  var arrClassNames = newValue.split(' ');
+  this.classNames = new Set(arrClassNames);
 };
 
-
-CSSClassList.prototype.add = function(/* variadic */) {
-    this.hasClass();
-    Object.values(arguments).forEach(this._addSingle.bind(this));
+CSSClassList.prototype.add = function (/* variadic */) {
+  this.hasClass();
+  Object.values(arguments).forEach(this._addSingle.bind(this));
 };
 
-CSSClassList.prototype._addSingle = function(className) {
-    this.classNames.add(className);
+CSSClassList.prototype._addSingle = function (className) {
+  this.classNames.add(className);
 };
 
-
-CSSClassList.prototype.remove = function(/* variadic */) {
-    this.hasClass();
-    Object.values(arguments).forEach(this._removeSingle.bind(this));
+CSSClassList.prototype.remove = function (/* variadic */) {
+  this.hasClass();
+  Object.values(arguments).forEach(this._removeSingle.bind(this));
 };
 
-CSSClassList.prototype._removeSingle = function(className) {
+CSSClassList.prototype._removeSingle = function (className) {
+  this.classNames.delete(className);
+};
+
+CSSClassList.prototype.item = function (index) {
+  var arrClassNames = Array.from(this.classNames);
+  return arrClassNames[index];
+};
+
+CSSClassList.prototype.toggle = function (className, force) {
+  if (this.contains(className) || force === false) {
     this.classNames.delete(className);
+  }
+  this.classNames.add(className);
 };
 
-
-CSSClassList.prototype.item = function(index) {
-    var arrClassNames = Array.from(this.classNames);
-    return arrClassNames[index];
+CSSClassList.prototype.contains = function (className) {
+  return this.classNames.has(className);
 };
 
-CSSClassList.prototype.toggle = function(className, force) {
-    if(this.contains(className) || force === false) {
-        this.classNames.delete(className);
-    }
-    this.classNames.add(className);
-};
-
-CSSClassList.prototype.contains = function(className) {
-    return this.classNames.has(className);
-};
-
-
 module.exports = CSSClassList;
diff --git a/lib/svgo/css-select-adapter.js b/lib/svgo/css-select-adapter.js
index c37678cb..9cbb2c2f 100644
--- a/lib/svgo/css-select-adapter.js
+++ b/lib/svgo/css-select-adapter.js
@@ -6,45 +6,44 @@ var baseCssAdapter = require('css-select-base-adapter');
  * DOMUtils API for SVGO AST (used by css-select)
  */
 var svgoCssSelectAdapterMin = {
+  // is the node a tag?
+  // isTag: ( node:Node ) => isTag:Boolean
+  isTag: function (node) {
+    return node.isElem();
+  },
 
-    // is the node a tag?
-    // isTag: ( node:Node ) => isTag:Boolean
-    isTag: function(node) {
-        return node.isElem();
-    },
+  // get the parent of the node
+  // getParent: ( node:Node ) => parentNode:Node
+  // returns null when no parent exists
+  getParent: function (node) {
+    return node.parentNode || null;
+  },
 
-    // get the parent of the node
-    // getParent: ( node:Node ) => parentNode:Node
-    // returns null when no parent exists
-    getParent: function(node) {
-        return node.parentNode || null;
-    },
+  // get the node's children
+  // getChildren: ( node:Node ) => children:[Node]
+  getChildren: function (node) {
+    return node.content || [];
+  },
 
-    // get the node's children
-    // getChildren: ( node:Node ) => children:[Node]
-    getChildren: function(node) {
-        return node.content || [];
-    },
+  // get the name of the tag
+  // getName: ( elem:ElementNode ) => tagName:String
+  getName: function (elemAst) {
+    return elemAst.elem;
+  },
 
-    // get the name of the tag
-    // getName: ( elem:ElementNode ) => tagName:String
-    getName: function(elemAst) {
-        return elemAst.elem;
-    },
+  // get the text content of the node, and its children if it has any
+  // getText: ( node:Node ) => text:String
+  // returns empty string when there is no text
+  getText: function (node) {
+    return node.content[0].text || node.content[0].cdata || '';
+  },
 
-    // get the text content of the node, and its children if it has any
-    // getText: ( node:Node ) => text:String
-    // returns empty string when there is no text
-    getText: function(node) {
-        return node.content[0].text || node.content[0].cdata || '';
-    },
-
-    // get the attribute value
-    // getAttributeValue: ( elem:ElementNode, name:String ) => value:String
-    // returns null when attribute doesn't exist
-    getAttributeValue: function(elem, name) {
-        return elem.hasAttr(name) ? elem.attr(name).value : null;
-    }
+  // get the attribute value
+  // getAttributeValue: ( elem:ElementNode, name:String ) => value:String
+  // returns null when attribute doesn't exist
+  getAttributeValue: function (elem, name) {
+    return elem.hasAttr(name) ? elem.attr(name).value : null;
+  },
 };
 
 // use base adapter for default implementation
diff --git a/lib/svgo/css-style-declaration.js b/lib/svgo/css-style-declaration.js
index fb6d7811..6d07952d 100644
--- a/lib/svgo/css-style-declaration.js
+++ b/lib/svgo/css-style-declaration.js
@@ -1,19 +1,18 @@
 'use strict';
 
 var csstree = require('css-tree'),
-    csstools = require('../css-tools');
+  csstools = require('../css-tools');
 
+var CSSStyleDeclaration = function (node) {
+  this.parentNode = node;
 
-var CSSStyleDeclaration = function(node) {
-    this.parentNode = node;
+  this.properties = new Map();
+  this.hasSynced = false;
 
-    this.properties = new Map();
-    this.hasSynced = false;
+  this.styleAttr = null;
+  this.styleValue = null;
 
-    this.styleAttr = null;
-    this.styleValue = null;
-
-    this.parseError = false;
+  this.parseError = false;
 };
 
 /**
@@ -21,124 +20,120 @@ var CSSStyleDeclaration = function(node) {
  *
  * @param parentNode the parentNode to assign to the cloned result
  */
-CSSStyleDeclaration.prototype.clone = function(parentNode) {
-    var node = this;
-    var nodeData = {};
+CSSStyleDeclaration.prototype.clone = function (parentNode) {
+  var node = this;
+  var nodeData = {};
 
-    Object.keys(node).forEach(function(key) {
-        if (key !== 'parentNode') {
-            nodeData[key] = node[key];
-        }
-    });
+  Object.keys(node).forEach(function (key) {
+    if (key !== 'parentNode') {
+      nodeData[key] = node[key];
+    }
+  });
 
-    // Deep-clone node data.
-    nodeData = JSON.parse(JSON.stringify(nodeData));
+  // Deep-clone node data.
+  nodeData = JSON.parse(JSON.stringify(nodeData));
 
-    var clone = new CSSStyleDeclaration(parentNode);
-    Object.assign(clone, nodeData);
-    return clone;
+  var clone = new CSSStyleDeclaration(parentNode);
+  Object.assign(clone, nodeData);
+  return clone;
 };
 
-CSSStyleDeclaration.prototype.hasStyle = function() {
-    this.addStyleHandler();
+CSSStyleDeclaration.prototype.hasStyle = function () {
+  this.addStyleHandler();
 };
 
-
-
-
 // attr.style
 
-CSSStyleDeclaration.prototype.addStyleHandler = function() {
+CSSStyleDeclaration.prototype.addStyleHandler = function () {
+  this.styleAttr = {
+    // empty style attr
+    name: 'style',
+    value: null,
+  };
 
-    this.styleAttr = { // empty style attr
-        'name': 'style',
-        'value': null
-    };
+  Object.defineProperty(this.parentNode.attrs, 'style', {
+    get: this.getStyleAttr.bind(this),
+    set: this.setStyleAttr.bind(this),
+    enumerable: true,
+    configurable: true,
+  });
 
-    Object.defineProperty(this.parentNode.attrs, 'style', {
-        get: this.getStyleAttr.bind(this),
-        set: this.setStyleAttr.bind(this),
-        enumerable: true,
-        configurable: true
-    });
-
-    this.addStyleValueHandler();
+  this.addStyleValueHandler();
 };
 
 // attr.style.value
 
-CSSStyleDeclaration.prototype.addStyleValueHandler = function() {
+CSSStyleDeclaration.prototype.addStyleValueHandler = function () {
+  Object.defineProperty(this.styleAttr, 'value', {
+    get: this.getStyleValue.bind(this),
+    set: this.setStyleValue.bind(this),
+    enumerable: true,
+    configurable: true,
+  });
+};
 
-    Object.defineProperty(this.styleAttr, 'value', {
-        get: this.getStyleValue.bind(this),
-        set: this.setStyleValue.bind(this),
-        enumerable: true,
-        configurable: true
+CSSStyleDeclaration.prototype.getStyleAttr = function () {
+  return this.styleAttr;
+};
+
+CSSStyleDeclaration.prototype.setStyleAttr = function (newStyleAttr) {
+  this.setStyleValue(newStyleAttr.value); // must before applying value handler!
+
+  this.styleAttr = newStyleAttr;
+  this.addStyleValueHandler();
+  this.hasSynced = false; // raw css changed
+};
+
+CSSStyleDeclaration.prototype.getStyleValue = function () {
+  return this.getCssText();
+};
+
+CSSStyleDeclaration.prototype.setStyleValue = function (newValue) {
+  this.properties.clear(); // reset all existing properties
+  this.styleValue = newValue;
+  this.hasSynced = false; // raw css changed
+};
+
+CSSStyleDeclaration.prototype._loadCssText = function () {
+  if (this.hasSynced) {
+    return;
+  }
+  this.hasSynced = true; // must be set here to prevent loop in setProperty(...)
+
+  if (!this.styleValue || this.styleValue.length === 0) {
+    return;
+  }
+  var inlineCssStr = this.styleValue;
+
+  var declarations = {};
+  try {
+    declarations = csstree.parse(inlineCssStr, {
+      context: 'declarationList',
+      parseValue: false,
     });
-};
+  } catch (parseError) {
+    this.parseError = parseError;
+    return;
+  }
+  this.parseError = false;
 
-CSSStyleDeclaration.prototype.getStyleAttr = function() {
-    return this.styleAttr;
-};
-
-CSSStyleDeclaration.prototype.setStyleAttr = function(newStyleAttr) {
-    this.setStyleValue(newStyleAttr.value); // must before applying value handler!
-
-    this.styleAttr = newStyleAttr;
-    this.addStyleValueHandler();
-    this.hasSynced = false; // raw css changed
-};
-
-CSSStyleDeclaration.prototype.getStyleValue = function() {
-    return this.getCssText();
-};
-
-CSSStyleDeclaration.prototype.setStyleValue = function(newValue) {
-    this.properties.clear(); // reset all existing properties
-    this.styleValue = newValue;
-    this.hasSynced = false; // raw css changed
-};
-
-
-
-
-CSSStyleDeclaration.prototype._loadCssText = function() {
-    if (this.hasSynced) {
-        return;
-    }
-    this.hasSynced = true; // must be set here to prevent loop in setProperty(...)
-
-    if (!this.styleValue || this.styleValue.length === 0) {
-        return;
-    }
-    var inlineCssStr = this.styleValue;
-
-    var declarations = {};
+  var self = this;
+  declarations.children.each(function (declaration) {
     try {
-        declarations = csstree.parse(inlineCssStr, {
-            context: 'declarationList',
-            parseValue: false
-        });
-    } catch (parseError) {
-        this.parseError = parseError;
-        return;
+      var styleDeclaration = csstools.csstreeToStyleDeclaration(declaration);
+      self.setProperty(
+        styleDeclaration.name,
+        styleDeclaration.value,
+        styleDeclaration.priority
+      );
+    } catch (styleError) {
+      if (styleError.message !== 'Unknown node type: undefined') {
+        self.parseError = styleError;
+      }
     }
-    this.parseError = false;
-
-    var self = this;
-    declarations.children.each(function(declaration) {
-        try {
-          var styleDeclaration = csstools.csstreeToStyleDeclaration(declaration);
-          self.setProperty(styleDeclaration.name, styleDeclaration.value, styleDeclaration.priority);
-        } catch(styleError) {
-            if(styleError.message !== 'Unknown node type: undefined') {
-                self.parseError = styleError;
-            }
-        }
-    });
+  });
 };
 
-
 // only reads from properties
 
 /**
@@ -146,39 +141,43 @@ CSSStyleDeclaration.prototype._loadCssText = function() {
  *
  * @return {String} Textual representation of the declaration block (empty string for no properties)
  */
-CSSStyleDeclaration.prototype.getCssText = function() {
-    var properties = this.getProperties();
+CSSStyleDeclaration.prototype.getCssText = function () {
+  var properties = this.getProperties();
 
-    if (this.parseError) {
-        // in case of a parse error, pass through original styles
-        return this.styleValue;
-    }
+  if (this.parseError) {
+    // in case of a parse error, pass through original styles
+    return this.styleValue;
+  }
 
-    var cssText = [];
-    properties.forEach(function(property, propertyName) {
-        var strImportant = property.priority === 'important' ? '!important' : '';
-        cssText.push(propertyName.trim() + ':' + property.value.trim() + strImportant);
-    });
-    return cssText.join(';');
+  var cssText = [];
+  properties.forEach(function (property, propertyName) {
+    var strImportant = property.priority === 'important' ? '!important' : '';
+    cssText.push(
+      propertyName.trim() + ':' + property.value.trim() + strImportant
+    );
+  });
+  return cssText.join(';');
 };
 
-CSSStyleDeclaration.prototype._handleParseError = function() {
-    if (this.parseError) {
-        console.warn('Warning: Parse error when parsing inline styles, style properties of this element cannot be used. The raw styles can still be get/set using .attr(\'style\').value. Error details: ' + this.parseError);
-    }
+CSSStyleDeclaration.prototype._handleParseError = function () {
+  if (this.parseError) {
+    console.warn(
+      "Warning: Parse error when parsing inline styles, style properties of this element cannot be used. The raw styles can still be get/set using .attr('style').value. Error details: " +
+        this.parseError
+    );
+  }
 };
 
+CSSStyleDeclaration.prototype._getProperty = function (propertyName) {
+  if (typeof propertyName === 'undefined') {
+    throw Error('1 argument required, but only 0 present.');
+  }
 
-CSSStyleDeclaration.prototype._getProperty = function(propertyName) {
-    if(typeof propertyName === 'undefined') {
-        throw Error('1 argument required, but only 0 present.');
-    }
+  var properties = this.getProperties();
+  this._handleParseError();
 
-    var properties = this.getProperties();
-    this._handleParseError();
-
-    var property = properties.get(propertyName.trim());
-    return property;
+  var property = properties.get(propertyName.trim());
+  return property;
 };
 
 /**
@@ -187,9 +186,9 @@ CSSStyleDeclaration.prototype._getProperty = function(propertyName) {
  * @param {String} propertyName representing the property name to be checked.
  * @return {String} priority that represents the priority (e.g. "important") if one exists. If none exists, returns the empty string.
  */
-CSSStyleDeclaration.prototype.getPropertyPriority = function(propertyName) {
-    var property = this._getProperty(propertyName);
-    return property ? property.priority : '';
+CSSStyleDeclaration.prototype.getPropertyPriority = function (propertyName) {
+  var property = this._getProperty(propertyName);
+  return property ? property.priority : '';
 };
 
 /**
@@ -198,9 +197,9 @@ CSSStyleDeclaration.prototype.getPropertyPriority = function(propertyName) {
  * @param {String} propertyName representing the property name to be checked.
  * @return {String} value containing the value of the property. If not set, returns the empty string.
  */
-CSSStyleDeclaration.prototype.getPropertyValue = function(propertyName) {
-    var property = this._getProperty(propertyName);
-    return property ? property.value : null;
+CSSStyleDeclaration.prototype.getPropertyValue = function (propertyName) {
+  var property = this._getProperty(propertyName);
+  return property ? property.value : null;
 };
 
 /**
@@ -209,15 +208,15 @@ CSSStyleDeclaration.prototype.getPropertyValue = function(propertyName) {
  * @param {Number} index of the node to be fetched. The index is zero-based.
  * @return {String} propertyName that is the name of the CSS property at the specified index.
  */
-CSSStyleDeclaration.prototype.item = function(index) {
-    if(typeof index === 'undefined') {
-        throw Error('1 argument required, but only 0 present.');
-    }
+CSSStyleDeclaration.prototype.item = function (index) {
+  if (typeof index === 'undefined') {
+    throw Error('1 argument required, but only 0 present.');
+  }
 
-    var properties = this.getProperties();
-    this._handleParseError();
+  var properties = this.getProperties();
+  this._handleParseError();
 
-    return Array.from(properties.keys())[index];
+  return Array.from(properties.keys())[index];
 };
 
 /**
@@ -225,12 +224,11 @@ CSSStyleDeclaration.prototype.item = function(index) {
  *
  * @return {Map} properties that is a Map with propertyName as key and property (propertyValue + propertyPriority) as value.
  */
-CSSStyleDeclaration.prototype.getProperties = function() {
-    this._loadCssText();
-    return this.properties;
+CSSStyleDeclaration.prototype.getProperties = function () {
+  this._loadCssText();
+  return this.properties;
 };
 
-
 // writes to properties
 
 /**
@@ -239,19 +237,19 @@ CSSStyleDeclaration.prototype.getProperties = function() {
  * @param {String} propertyName representing the property name to be removed.
  * @return {String} oldValue equal to the value of the CSS property before it was removed.
  */
-CSSStyleDeclaration.prototype.removeProperty = function(propertyName) {
-    if(typeof propertyName === 'undefined') {
-        throw Error('1 argument required, but only 0 present.');
-    }
+CSSStyleDeclaration.prototype.removeProperty = function (propertyName) {
+  if (typeof propertyName === 'undefined') {
+    throw Error('1 argument required, but only 0 present.');
+  }
 
-    this.hasStyle();
+  this.hasStyle();
 
-    var properties = this.getProperties();
-    this._handleParseError();
+  var properties = this.getProperties();
+  this._handleParseError();
 
-    var oldValue = this.getPropertyValue(propertyName);
-    properties.delete(propertyName.trim());
-    return oldValue;
+  var oldValue = this.getPropertyValue(propertyName);
+  properties.delete(propertyName.trim());
+  return oldValue;
 };
 
 /**
@@ -262,24 +260,27 @@ CSSStyleDeclaration.prototype.removeProperty = function(propertyName) {
  * @param {String} [priority] allowing the "important" CSS priority to be set. If not specified, treated as the empty string.
  * @return {undefined}
  */
-CSSStyleDeclaration.prototype.setProperty = function(propertyName, value, priority) {
-    if(typeof propertyName === 'undefined') {
-        throw Error('propertyName argument required, but only not present.');
-    }
+CSSStyleDeclaration.prototype.setProperty = function (
+  propertyName,
+  value,
+  priority
+) {
+  if (typeof propertyName === 'undefined') {
+    throw Error('propertyName argument required, but only not present.');
+  }
 
-    this.hasStyle();
+  this.hasStyle();
 
-    var properties = this.getProperties();
-    this._handleParseError();
+  var properties = this.getProperties();
+  this._handleParseError();
 
-    var property = {
-        value: value.trim(),
-        priority: priority.trim()
-    };
-    properties.set(propertyName.trim(), property);
+  var property = {
+    value: value.trim(),
+    priority: priority.trim(),
+  };
+  properties.set(propertyName.trim(), property);
 
-    return property;
+  return property;
 };
 
-
 module.exports = CSSStyleDeclaration;
diff --git a/lib/svgo/js2svg.js b/lib/svgo/js2svg.js
index f29838c7..8cb7f484 100644
--- a/lib/svgo/js2svg.js
+++ b/lib/svgo/js2svg.js
@@ -1,42 +1,42 @@
 'use strict';
 
 var EOL = require('os').EOL,
-    textElems = require('../../plugins/_collections.js').textElems;
+  textElems = require('../../plugins/_collections.js').textElems;
 
 var defaults = {
-    doctypeStart: '<!DOCTYPE',
-    doctypeEnd: '>',
-    procInstStart: '<?',
-    procInstEnd: '?>',
-    tagOpenStart: '<',
-    tagOpenEnd: '>',
-    tagCloseStart: '</',
-    tagCloseEnd: '>',
-    tagShortStart: '<',
-    tagShortEnd: '/>',
-    attrStart: '="',
-    attrEnd: '"',
-    commentStart: '<!--',
-    commentEnd: '-->',
-    cdataStart: '<![CDATA[',
-    cdataEnd: ']]>',
-    textStart: '',
-    textEnd: '',
-    indent: 4,
-    regEntities: /[&'"<>]/g,
-    regValEntities: /[&"<>]/g,
-    encodeEntity: encodeEntity,
-    pretty: false,
-    useShortTags: true
+  doctypeStart: '<!DOCTYPE',
+  doctypeEnd: '>',
+  procInstStart: '<?',
+  procInstEnd: '?>',
+  tagOpenStart: '<',
+  tagOpenEnd: '>',
+  tagCloseStart: '</',
+  tagCloseEnd: '>',
+  tagShortStart: '<',
+  tagShortEnd: '/>',
+  attrStart: '="',
+  attrEnd: '"',
+  commentStart: '<!--',
+  commentEnd: '-->',
+  cdataStart: '<![CDATA[',
+  cdataEnd: ']]>',
+  textStart: '',
+  textEnd: '',
+  indent: 4,
+  regEntities: /[&'"<>]/g,
+  regValEntities: /[&"<>]/g,
+  encodeEntity: encodeEntity,
+  pretty: false,
+  useShortTags: true,
 };
 
 var entities = {
-      '&': '&amp;',
-      '\'': '&apos;',
-      '"': '&quot;',
-      '>': '&gt;',
-      '<': '&lt;',
-    };
+  '&': '&amp;',
+  "'": '&apos;',
+  '"': '&quot;',
+  '>': '&gt;',
+  '<': '&lt;',
+};
 
 /**
  * Convert SVG-as-JS object to SVG (XML) string.
@@ -46,45 +46,41 @@ var entities = {
  *
  * @return {Object} output data
  */
-module.exports = function(data, config) {
-
-    return new JS2SVG(config).convert(data);
-
+module.exports = function (data, config) {
+  return new JS2SVG(config).convert(data);
 };
 
 function JS2SVG(config) {
+  if (config) {
+    this.config = Object.assign({}, defaults, config);
+  } else {
+    this.config = Object.assign({}, defaults);
+  }
 
-    if (config) {
-        this.config = Object.assign({}, defaults, config);
-    } else {
-        this.config = Object.assign({}, defaults);
-    }
+  var indent = this.config.indent;
+  if (typeof indent == 'number' && !isNaN(indent)) {
+    this.config.indent = indent < 0 ? '\t' : ' '.repeat(indent);
+  } else if (typeof indent != 'string') {
+    this.config.indent = '    ';
+  }
 
-    var indent = this.config.indent;
-    if (typeof indent == 'number' && !isNaN(indent)) {
-        this.config.indent = (indent < 0) ? '\t' : ' '.repeat(indent);
-    } else if (typeof indent != 'string') {
-        this.config.indent = '    ';
-    }
-
-    if (this.config.pretty) {
-        this.config.doctypeEnd += EOL;
-        this.config.procInstEnd += EOL;
-        this.config.commentEnd += EOL;
-        this.config.cdataEnd += EOL;
-        this.config.tagShortEnd += EOL;
-        this.config.tagOpenEnd += EOL;
-        this.config.tagCloseEnd += EOL;
-        this.config.textEnd += EOL;
-    }
-
-    this.indentLevel = 0;
-    this.textContext = null;
+  if (this.config.pretty) {
+    this.config.doctypeEnd += EOL;
+    this.config.procInstEnd += EOL;
+    this.config.commentEnd += EOL;
+    this.config.cdataEnd += EOL;
+    this.config.tagShortEnd += EOL;
+    this.config.tagOpenEnd += EOL;
+    this.config.tagCloseEnd += EOL;
+    this.config.textEnd += EOL;
+  }
 
+  this.indentLevel = 0;
+  this.textContext = null;
 }
 
 function encodeEntity(char) {
-    return entities[char];
+  return entities[char];
 }
 
 /**
@@ -94,44 +90,38 @@ function encodeEntity(char) {
  *
  * @return {String}
  */
-JS2SVG.prototype.convert = function(data) {
+JS2SVG.prototype.convert = function (data) {
+  var svg = '';
 
-    var svg = '';
+  if (data.content) {
+    this.indentLevel++;
 
-    if (data.content) {
+    data.content.forEach(function (item) {
+      if (item.elem) {
+        svg += this.createElem(item);
+      } else if (item.text) {
+        svg += this.createText(item.text);
+      } else if (item.doctype) {
+        svg += this.createDoctype(item.doctype);
+      } else if (item.processinginstruction) {
+        svg += this.createProcInst(item.processinginstruction);
+      } else if (item.comment) {
+        svg += this.createComment(item.comment);
+      } else if (item.cdata) {
+        svg += this.createCDATA(item.cdata);
+      }
+    }, this);
+  }
 
-        this.indentLevel++;
-
-        data.content.forEach(function(item) {
-
-            if (item.elem) {
-               svg += this.createElem(item);
-            } else if (item.text) {
-               svg += this.createText(item.text);
-            } else if (item.doctype) {
-                svg += this.createDoctype(item.doctype);
-            } else if (item.processinginstruction) {
-                svg += this.createProcInst(item.processinginstruction);
-            } else if (item.comment) {
-                svg += this.createComment(item.comment);
-            } else if (item.cdata) {
-                svg += this.createCDATA(item.cdata);
-            }
-
-        }, this);
-
-    }
-
-    this.indentLevel--;
-
-    return {
-        data: svg,
-        info: {
-            width: this.width,
-            height: this.height
-        }
-    };
+  this.indentLevel--;
 
+  return {
+    data: svg,
+    info: {
+      width: this.width,
+      height: this.height,
+    },
+  };
 };
 
 /**
@@ -139,16 +129,14 @@ JS2SVG.prototype.convert = function(data) {
  *
  * @return {String}
  */
-JS2SVG.prototype.createIndent = function() {
+JS2SVG.prototype.createIndent = function () {
+  var indent = '';
 
-    var indent = '';
-
-    if (this.config.pretty && !this.textContext) {
-        indent = this.config.indent.repeat(this.indentLevel - 1);
-    }
-
-    return indent;
+  if (this.config.pretty && !this.textContext) {
+    indent = this.config.indent.repeat(this.indentLevel - 1);
+  }
 
+  return indent;
 };
 
 /**
@@ -158,12 +146,8 @@ JS2SVG.prototype.createIndent = function() {
  *
  * @return {String}
  */
-JS2SVG.prototype.createDoctype = function(doctype) {
-
-    return  this.config.doctypeStart +
-            doctype +
-            this.config.doctypeEnd;
-
+JS2SVG.prototype.createDoctype = function (doctype) {
+  return this.config.doctypeStart + doctype + this.config.doctypeEnd;
 };
 
 /**
@@ -173,14 +157,14 @@ JS2SVG.prototype.createDoctype = function(doctype) {
  *
  * @return {String}
  */
-JS2SVG.prototype.createProcInst = function(instruction) {
-
-    return  this.config.procInstStart +
-            instruction.name +
-            ' ' +
-            instruction.body +
-            this.config.procInstEnd;
-
+JS2SVG.prototype.createProcInst = function (instruction) {
+  return (
+    this.config.procInstStart +
+    instruction.name +
+    ' ' +
+    instruction.body +
+    this.config.procInstEnd
+  );
 };
 
 /**
@@ -190,12 +174,8 @@ JS2SVG.prototype.createProcInst = function(instruction) {
  *
  * @return {String}
  */
-JS2SVG.prototype.createComment = function(comment) {
-
-    return  this.config.commentStart +
-            comment +
-            this.config.commentEnd;
-
+JS2SVG.prototype.createComment = function (comment) {
+  return this.config.commentStart + comment + this.config.commentEnd;
 };
 
 /**
@@ -205,13 +185,10 @@ JS2SVG.prototype.createComment = function(comment) {
  *
  * @return {String}
  */
-JS2SVG.prototype.createCDATA = function(cdata) {
-
-    return  this.createIndent() +
-            this.config.cdataStart +
-            cdata +
-            this.config.cdataEnd;
-
+JS2SVG.prototype.createCDATA = function (cdata) {
+  return (
+    this.createIndent() + this.config.cdataStart + cdata + this.config.cdataEnd
+  );
 };
 
 /**
@@ -221,80 +198,79 @@ JS2SVG.prototype.createCDATA = function(cdata) {
  *
  * @return {String}
  */
-JS2SVG.prototype.createElem = function(data) {
+JS2SVG.prototype.createElem = function (data) {
+  // beautiful injection for obtaining SVG information :)
+  if (data.isElem('svg') && data.hasAttr('width') && data.hasAttr('height')) {
+    this.width = data.attr('width').value;
+    this.height = data.attr('height').value;
+  }
 
-    // beautiful injection for obtaining SVG information :)
-    if (
-        data.isElem('svg') &&
-        data.hasAttr('width') &&
-        data.hasAttr('height')
-    ) {
-        this.width = data.attr('width').value;
-        this.height = data.attr('height').value;
-    }
-
-    // empty element and short tag
-    if (data.isEmpty()) {
-        if (this.config.useShortTags) {
-            return this.createIndent() +
-                   this.config.tagShortStart +
-                   data.elem +
-                   this.createAttrs(data) +
-                   this.config.tagShortEnd;
-        } else {
-            return this.createIndent() +
-                   this.config.tagShortStart +
-                   data.elem +
-                   this.createAttrs(data) +
-                   this.config.tagOpenEnd +
-                   this.config.tagCloseStart +
-                   data.elem +
-                   this.config.tagCloseEnd;
-        }
-    // non-empty element
+  // empty element and short tag
+  if (data.isEmpty()) {
+    if (this.config.useShortTags) {
+      return (
+        this.createIndent() +
+        this.config.tagShortStart +
+        data.elem +
+        this.createAttrs(data) +
+        this.config.tagShortEnd
+      );
     } else {
-        var tagOpenStart = this.config.tagOpenStart,
-            tagOpenEnd = this.config.tagOpenEnd,
-            tagCloseStart = this.config.tagCloseStart,
-            tagCloseEnd = this.config.tagCloseEnd,
-            openIndent = this.createIndent(),
-            closeIndent = this.createIndent(),
-            processedData = '',
-            dataEnd = '';
-
-        if (this.textContext) {
-            tagOpenStart = defaults.tagOpenStart;
-            tagOpenEnd = defaults.tagOpenEnd;
-            tagCloseStart = defaults.tagCloseStart;
-            tagCloseEnd = defaults.tagCloseEnd;
-            openIndent = '';
-        } else if (data.isElem(textElems)) {
-            tagOpenEnd = defaults.tagOpenEnd;
-            tagCloseStart = defaults.tagCloseStart;
-            closeIndent = '';
-            this.textContext = data;
-        }
-
-        processedData += this.convert(data).data;
-
-        if (this.textContext == data) {
-            this.textContext = null;
-        }
-
-        return  openIndent +
-                tagOpenStart +
-                data.elem +
-                this.createAttrs(data) +
-                tagOpenEnd +
-                processedData +
-                dataEnd +
-                closeIndent +
-                tagCloseStart +
-                data.elem +
-                tagCloseEnd;
+      return (
+        this.createIndent() +
+        this.config.tagShortStart +
+        data.elem +
+        this.createAttrs(data) +
+        this.config.tagOpenEnd +
+        this.config.tagCloseStart +
+        data.elem +
+        this.config.tagCloseEnd
+      );
+    }
+    // non-empty element
+  } else {
+    var tagOpenStart = this.config.tagOpenStart,
+      tagOpenEnd = this.config.tagOpenEnd,
+      tagCloseStart = this.config.tagCloseStart,
+      tagCloseEnd = this.config.tagCloseEnd,
+      openIndent = this.createIndent(),
+      closeIndent = this.createIndent(),
+      processedData = '',
+      dataEnd = '';
 
+    if (this.textContext) {
+      tagOpenStart = defaults.tagOpenStart;
+      tagOpenEnd = defaults.tagOpenEnd;
+      tagCloseStart = defaults.tagCloseStart;
+      tagCloseEnd = defaults.tagCloseEnd;
+      openIndent = '';
+    } else if (data.isElem(textElems)) {
+      tagOpenEnd = defaults.tagOpenEnd;
+      tagCloseStart = defaults.tagCloseStart;
+      closeIndent = '';
+      this.textContext = data;
     }
 
+    processedData += this.convert(data).data;
+
+    if (this.textContext == data) {
+      this.textContext = null;
+    }
+
+    return (
+      openIndent +
+      tagOpenStart +
+      data.elem +
+      this.createAttrs(data) +
+      tagOpenEnd +
+      processedData +
+      dataEnd +
+      closeIndent +
+      tagCloseStart +
+      data.elem +
+      tagCloseEnd
+    );
+  }
 };
 
 /**
@@ -304,29 +280,26 @@ JS2SVG.prototype.createElem = function(data) {
  *
  * @return {String}
  */
-JS2SVG.prototype.createAttrs = function(elem) {
+JS2SVG.prototype.createAttrs = function (elem) {
+  var attrs = '';
 
-    var attrs = '';
-
-    elem.eachAttr(function(attr) {
-
-        if (attr.value !== undefined) {
-            attrs +=    ' ' +
-                        attr.name +
-                        this.config.attrStart +
-                        String(attr.value).replace(this.config.regValEntities, this.config.encodeEntity) +
-                        this.config.attrEnd;
-        }
-        else {
-            attrs +=    ' ' +
-                        attr.name;
-        }
-
-
-    }, this);
-
-    return attrs;
+  elem.eachAttr(function (attr) {
+    if (attr.value !== undefined) {
+      attrs +=
+        ' ' +
+        attr.name +
+        this.config.attrStart +
+        String(attr.value).replace(
+          this.config.regValEntities,
+          this.config.encodeEntity
+        ) +
+        this.config.attrEnd;
+    } else {
+      attrs += ' ' + attr.name;
+    }
+  }, this);
 
+  return attrs;
 };
 
 /**
@@ -336,11 +309,11 @@ JS2SVG.prototype.createAttrs = function(elem) {
  *
  * @return {String}
  */
-JS2SVG.prototype.createText = function(text) {
-
-    return  this.createIndent() +
-            this.config.textStart +
-            text.replace(this.config.regEntities, this.config.encodeEntity) +
-            (this.textContext ? '' : this.config.textEnd);
-
+JS2SVG.prototype.createText = function (text) {
+  return (
+    this.createIndent() +
+    this.config.textStart +
+    text.replace(this.config.regEntities, this.config.encodeEntity) +
+    (this.textContext ? '' : this.config.textEnd)
+  );
 };
diff --git a/lib/svgo/jsAPI.js b/lib/svgo/jsAPI.js
index 282ab6b4..df9993be 100644
--- a/lib/svgo/jsAPI.js
+++ b/lib/svgo/jsAPI.js
@@ -5,57 +5,58 @@ const svgoCssSelectAdapter = require('./css-select-adapter');
 
 var cssSelectOpts = {
   xmlMode: true,
-  adapter: svgoCssSelectAdapter
+  adapter: svgoCssSelectAdapter,
 };
 
-var JSAPI = module.exports = function(data, parentNode) {
-    Object.assign(this, data);
-    if (parentNode) {
-        Object.defineProperty(this, 'parentNode', {
-            writable: true,
-            value: parentNode
-        });
-    }
+var JSAPI = function (data, parentNode) {
+  Object.assign(this, data);
+  if (parentNode) {
+    Object.defineProperty(this, 'parentNode', {
+      writable: true,
+      value: parentNode,
+    });
+  }
 };
+module.exports = JSAPI;
 
 /**
  * Perform a deep clone of this node.
  *
  * @return {Object} element
  */
-JSAPI.prototype.clone = function() {
-    var node = this;
-    var nodeData = {};
+JSAPI.prototype.clone = function () {
+  var node = this;
+  var nodeData = {};
 
-    Object.keys(node).forEach(function(key) {
-        if (key !== 'class' && key !== 'style' && key !== 'content') {
-            nodeData[key] = node[key];
-        }
+  Object.keys(node).forEach(function (key) {
+    if (key !== 'class' && key !== 'style' && key !== 'content') {
+      nodeData[key] = node[key];
+    }
+  });
+
+  // Deep-clone node data.
+  nodeData = JSON.parse(JSON.stringify(nodeData));
+
+  // parentNode gets set to a proper object by the parent clone,
+  // but it needs to be true/false now to do the right thing
+  // in the constructor.
+  var clonedNode = new JSAPI(nodeData, !!node.parentNode);
+
+  if (node.class) {
+    clonedNode.class = node.class.clone(clonedNode);
+  }
+  if (node.style) {
+    clonedNode.style = node.style.clone(clonedNode);
+  }
+  if (node.content) {
+    clonedNode.content = node.content.map(function (childNode) {
+      var clonedChild = childNode.clone();
+      clonedChild.parentNode = clonedNode;
+      return clonedChild;
     });
+  }
 
-    // Deep-clone node data.
-    nodeData = JSON.parse(JSON.stringify(nodeData));
-
-    // parentNode gets set to a proper object by the parent clone,
-    // but it needs to be true/false now to do the right thing
-    // in the constructor.
-    var clonedNode = new JSAPI(nodeData, !!node.parentNode);
-
-    if (node.class) {
-        clonedNode.class = node.class.clone(clonedNode);
-    }
-    if (node.style) {
-        clonedNode.style = node.style.clone(clonedNode);
-    }
-    if (node.content) {
-        clonedNode.content = node.content.map(function(childNode) {
-            var clonedChild = childNode.clone();
-            clonedChild.parentNode = clonedNode;
-            return clonedChild;
-        });
-    }
-
-    return clonedNode;
+  return clonedNode;
 };
 
 /**
@@ -65,14 +66,12 @@ JSAPI.prototype.clone = function() {
  * @param {String|Array} [param] element name or names arrays
  * @return {Boolean}
  */
-JSAPI.prototype.isElem = function(param) {
+JSAPI.prototype.isElem = function (param) {
+  if (!param) return !!this.elem;
 
-    if (!param) return !!this.elem;
-
-    if (Array.isArray(param)) return !!this.elem && (param.indexOf(this.elem) > -1);
-
-    return !!this.elem && this.elem === param;
+  if (Array.isArray(param)) return !!this.elem && param.indexOf(this.elem) > -1;
 
+  return !!this.elem && this.elem === param;
 };
 
 /**
@@ -81,13 +80,10 @@ JSAPI.prototype.isElem = function(param) {
  * @param {String} name new element name
  * @return {Object} element
  */
-JSAPI.prototype.renameElem = function(name) {
-
-    if (name && typeof name === 'string')
-        this.elem = this.local = name;
-
-    return this;
+JSAPI.prototype.renameElem = function (name) {
+  if (name && typeof name === 'string') this.elem = this.local = name;
 
+  return this;
 };
 
 /**
@@ -95,10 +91,8 @@ JSAPI.prototype.renameElem = function(name) {
  *
  * @return {Boolean}
  */
- JSAPI.prototype.isEmpty = function() {
-
-    return !this.content || !this.content.length;
-
+JSAPI.prototype.isEmpty = function () {
+  return !this.content || !this.content.length;
 };
 
 /**
@@ -107,12 +101,12 @@ JSAPI.prototype.renameElem = function(name) {
  *
  * @return {?Object}
  */
- JSAPI.prototype.closestElem = function(elemName) {
-    var elem = this;
+JSAPI.prototype.closestElem = function (elemName) {
+  var elem = this;
 
-    while ((elem = elem.parentNode) && !elem.isElem(elemName));
+  while ((elem = elem.parentNode) && !elem.isElem(elemName));
 
-    return elem;
+  return elem;
 };
 
 /**
@@ -123,18 +117,17 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {Array|Object} [insertion] Elements to add to the content.
  * @return {Array} Removed elements.
  */
- JSAPI.prototype.spliceContent = function(start, n, insertion) {
+JSAPI.prototype.spliceContent = function (start, n, insertion) {
+  if (arguments.length < 2) return [];
 
-    if (arguments.length < 2) return [];
-
-    if (!Array.isArray(insertion))
-        insertion = Array.apply(null, arguments).slice(2);
-
-    insertion.forEach(function(inner) { inner.parentNode = this }, this);
-
-    return this.content.splice.apply(this.content, [start, n].concat(insertion));
+  if (!Array.isArray(insertion))
+    insertion = Array.apply(null, arguments).slice(2);
 
+  insertion.forEach(function (inner) {
+    inner.parentNode = this;
+  }, this);
 
+  return this.content.splice.apply(this.content, [start, n].concat(insertion));
 };
 
 /**
@@ -145,16 +138,15 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {String} [val] attribute value (will be toString()'ed)
  * @return {Boolean}
  */
- JSAPI.prototype.hasAttr = function(name, val) {
+JSAPI.prototype.hasAttr = function (name, val) {
+  if (!this.attrs || !Object.keys(this.attrs).length) return false;
 
-    if (!this.attrs || !Object.keys(this.attrs).length) return false;
+  if (!arguments.length) return !!this.attrs;
 
-    if (!arguments.length) return !!this.attrs;
-
-    if (val !== undefined) return !!this.attrs[name] && this.attrs[name].value === val.toString();
-
-    return !!this.attrs[name];
+  if (val !== undefined)
+    return !!this.attrs[name] && this.attrs[name].value === val.toString();
 
+  return !!this.attrs[name];
 };
 
 /**
@@ -165,39 +157,44 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {Number|String|RegExp|Function} [val] attribute value (will be toString()'ed or executed, otherwise ignored)
  * @return {Boolean}
  */
- JSAPI.prototype.hasAttrLocal = function(localName, val) {
+JSAPI.prototype.hasAttrLocal = function (localName, val) {
+  if (!this.attrs || !Object.keys(this.attrs).length) return false;
 
-    if (!this.attrs || !Object.keys(this.attrs).length) return false;
+  if (!arguments.length) return !!this.attrs;
 
-    if (!arguments.length) return !!this.attrs;
+  var callback;
 
-    var callback;
+  switch (val != null && val.constructor && val.constructor.name) {
+    case 'Number': // same as String
+    case 'String':
+      callback = stringValueTest;
+      break;
+    case 'RegExp':
+      callback = regexpValueTest;
+      break;
+    case 'Function':
+      callback = funcValueTest;
+      break;
+    default:
+      callback = nameTest;
+  }
+  return this.someAttr(callback);
 
-    switch (val != null && val.constructor && val.constructor.name) {
-        case 'Number':   // same as String
-        case 'String':   callback = stringValueTest; break;
-        case 'RegExp':   callback = regexpValueTest; break;
-        case 'Function': callback = funcValueTest; break;
-        default:         callback = nameTest;
-    }
-    return this.someAttr(callback);
+  function nameTest(attr) {
+    return attr.local === localName;
+  }
 
-    function nameTest(attr) {
-        return attr.local === localName;
-    }
+  function stringValueTest(attr) {
+    return attr.local === localName && val == attr.value;
+  }
 
-    function stringValueTest(attr) {
-        return attr.local === localName && val == attr.value;
-    }
-
-    function regexpValueTest(attr) {
-        return attr.local === localName && val.test(attr.value);
-    }
-
-    function funcValueTest(attr) {
-        return attr.local === localName && val(attr.value);
-    }
+  function regexpValueTest(attr) {
+    return attr.local === localName && val.test(attr.value);
+  }
 
+  function funcValueTest(attr) {
+    return attr.local === localName && val(attr.value);
+  }
 };
 
 /**
@@ -208,14 +205,13 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {String} [val] attribute value (will be toString()'ed)
  * @return {Object|Undefined}
  */
- JSAPI.prototype.attr = function(name, val) {
+JSAPI.prototype.attr = function (name, val) {
+  if (!this.hasAttr() || !arguments.length) return undefined;
 
-    if (!this.hasAttr() || !arguments.length) return undefined;
-
-    if (val !== undefined) return this.hasAttr(name, val) ? this.attrs[name] : undefined;
-
-    return this.attrs[name];
+  if (val !== undefined)
+    return this.hasAttr(name, val) ? this.attrs[name] : undefined;
 
+  return this.attrs[name];
 };
 
 /**
@@ -224,17 +220,20 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {String} name attribute name
  * @return {Object|Undefined}
  */
- JSAPI.prototype.computedAttr = function(name, val) {
-    if (!arguments.length) return;
+JSAPI.prototype.computedAttr = function (name, val) {
+  if (!arguments.length) return;
 
-    for (var elem = this; elem && (!elem.hasAttr(name) || !elem.attr(name).value); elem = elem.parentNode);
-
-    if (val != null) {
-        return elem ? elem.hasAttr(name, val) : false;
-    } else if (elem && elem.hasAttr(name)) {
-        return elem.attrs[name].value;
-    }
+  for (
+    var elem = this;
+    elem && (!elem.hasAttr(name) || !elem.attr(name).value);
+    elem = elem.parentNode
+  );
 
+  if (val != null) {
+    return elem ? elem.hasAttr(name, val) : false;
+  } else if (elem && elem.hasAttr(name)) {
+    return elem.attrs[name].value;
+  }
 };
 
 /**
@@ -244,25 +243,23 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {String} [val] attribute value
  * @return {Boolean}
  */
- JSAPI.prototype.removeAttr = function(name, val, recursive) {
+JSAPI.prototype.removeAttr = function (name, val, recursive) {
+  if (!arguments.length) return false;
 
-    if (!arguments.length) return false;
+  if (Array.isArray(name)) {
+    name.forEach(this.removeAttr, this);
+    return false;
+  }
 
-    if (Array.isArray(name)) {
-        name.forEach(this.removeAttr, this);
-        return false;
-    }
+  if (!this.hasAttr(name)) return false;
 
-    if (!this.hasAttr(name)) return false;
+  if (!recursive && val && this.attrs[name].value !== val) return false;
 
-    if (!recursive && val && this.attrs[name].value !== val) return false;
+  delete this.attrs[name];
 
-    delete this.attrs[name];
-
-    if (!Object.keys(this.attrs).length) delete this.attrs;
-
-    return true;
+  if (!Object.keys(this.attrs).length) delete this.attrs;
 
+  return true;
 };
 
 /**
@@ -271,27 +268,30 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {Object} [attr={}] attribute object
  * @return {Object|Boolean} created attribute or false if no attr was passed in
  */
- JSAPI.prototype.addAttr = function(attr) {
-    attr = attr || {};
+JSAPI.prototype.addAttr = function (attr) {
+  attr = attr || {};
 
-    if (attr.name === undefined ||
-        attr.prefix === undefined ||
-        attr.local === undefined
-    ) return false;
+  if (
+    attr.name === undefined ||
+    attr.prefix === undefined ||
+    attr.local === undefined
+  )
+    return false;
 
-    this.attrs = this.attrs || {};
-    this.attrs[attr.name] = attr;
+  this.attrs = this.attrs || {};
+  this.attrs[attr.name] = attr;
 
-    if(attr.name === 'class') { // newly added class attribute
-        this.class.hasClass();
-    }
+  if (attr.name === 'class') {
+    // newly added class attribute
+    this.class.hasClass();
+  }
 
-    if(attr.name === 'style') { // newly added style attribute
-        this.style.hasStyle();
-    }
-
-    return this.attrs[attr.name];
+  if (attr.name === 'style') {
+    // newly added style attribute
+    this.style.hasStyle();
+  }
 
+  return this.attrs[attr.name];
 };
 
 /**
@@ -301,16 +301,14 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {Object} [context] callback context
  * @return {Boolean} false if there are no any attributes
  */
- JSAPI.prototype.eachAttr = function(callback, context) {
+JSAPI.prototype.eachAttr = function (callback, context) {
+  if (!this.hasAttr()) return false;
 
-    if (!this.hasAttr()) return false;
-
-    for (const attr of Object.values(this.attrs)) {
-        callback.call(context, attr);
-    }
-
-    return true;
+  for (const attr of Object.values(this.attrs)) {
+    callback.call(context, attr);
+  }
 
+  return true;
 };
 
 /**
@@ -320,16 +318,14 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {Object} [context] callback context
  * @return {Boolean} false if there are no any attributes
  */
- JSAPI.prototype.someAttr = function(callback, context) {
+JSAPI.prototype.someAttr = function (callback, context) {
+  if (!this.hasAttr()) return false;
 
-    if (!this.hasAttr()) return false;
-
-    for (const attr of Object.values(this.attrs)) {
-        if (callback.call(context, attr)) return true;
-    }
-
-    return false;
+  for (const attr of Object.values(this.attrs)) {
+    if (callback.call(context, attr)) return true;
+  }
 
+  return false;
 };
 
 /**
@@ -338,12 +334,10 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {String} selectors CSS selector(s) string
  * @return {Array} null if no elements matched
  */
- JSAPI.prototype.querySelectorAll = function(selectors) {
-
-   var matchedEls = selectAll(selectors, this, cssSelectOpts);
-
-   return matchedEls.length > 0 ? matchedEls : null;
+JSAPI.prototype.querySelectorAll = function (selectors) {
+  var matchedEls = selectAll(selectors, this, cssSelectOpts);
 
+  return matchedEls.length > 0 ? matchedEls : null;
 };
 
 /**
@@ -352,10 +346,8 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {String} selectors CSS selector(s) string
  * @return {Array} null if no element matched
  */
- JSAPI.prototype.querySelector = function(selectors) {
-
-   return selectOne(selectors, this, cssSelectOpts);
-
+JSAPI.prototype.querySelector = function (selectors) {
+  return selectOne(selectors, this, cssSelectOpts);
 };
 
 /**
@@ -364,8 +356,6 @@ JSAPI.prototype.renameElem = function(name) {
  * @param {String} selector CSS selector string
  * @return {Boolean} true if element would be selected by selector string, false if it does not
  */
- JSAPI.prototype.matches = function(selector) {
-
-   return is(this, selector, cssSelectOpts);
-
+JSAPI.prototype.matches = function (selector) {
+  return is(this, selector, cssSelectOpts);
 };
diff --git a/lib/svgo/plugins.js b/lib/svgo/plugins.js
index 26656d12..b4b32e06 100644
--- a/lib/svgo/plugins.js
+++ b/lib/svgo/plugins.js
@@ -10,7 +10,7 @@
  * @param {Object} plugins plugins object from config
  * @return {Object} output data
  */
-module.exports = function(data, info, plugins) {
+module.exports = function (data, info, plugins) {
   // Try to group sequential elements of plugins array
   // to optimize ast traversing
   const groups = [];
@@ -24,7 +24,7 @@ module.exports = function(data, info, plugins) {
     }
   }
   for (const group of groups) {
-    switch(group[0].type) {
+    switch (group[0].type) {
       case 'perItem':
         data = perItem(data, info, group);
         break;
@@ -49,42 +49,36 @@ module.exports = function(data, info, plugins) {
  * @return {Object} output data
  */
 function perItem(data, info, plugins, reverse) {
+  function monkeys(items) {
+    items.content = items.content.filter(function (item) {
+      // reverse pass
+      if (reverse && item.content) {
+        monkeys(item);
+      }
 
-    function monkeys(items) {
+      // main filter
+      var filter = true;
 
-        items.content = items.content.filter(function(item) {
+      for (var i = 0; filter && i < plugins.length; i++) {
+        var plugin = plugins[i];
 
-            // reverse pass
-            if (reverse && item.content) {
-                monkeys(item);
-            }
+        if (plugin.active && plugin.fn(item, plugin.params, info) === false) {
+          filter = false;
+        }
+      }
 
-            // main filter
-            var filter = true;
+      // direct pass
+      if (!reverse && item.content) {
+        monkeys(item);
+      }
 
-            for (var i = 0; filter && i < plugins.length; i++) {
-                var plugin = plugins[i];
+      return filter;
+    });
 
-                if (plugin.active && plugin.fn(item, plugin.params, info) === false) {
-                    filter = false;
-                }
-            }
-
-            // direct pass
-            if (!reverse && item.content) {
-                monkeys(item);
-            }
-
-            return filter;
-
-        });
-
-        return items;
-
-    }
-
-    return monkeys(data);
+    return items;
+  }
 
+  return monkeys(data);
 }
 
 /**
@@ -96,13 +90,11 @@ function perItem(data, info, plugins, reverse) {
  * @return {Object} output data
  */
 function full(data, info, plugins) {
+  plugins.forEach(function (plugin) {
+    if (plugin.active) {
+      data = plugin.fn(data, plugin.params, info);
+    }
+  });
 
-    plugins.forEach(function(plugin) {
-        if (plugin.active) {
-            data = plugin.fn(data, plugin.params, info);
-        }
-    });
-
-    return data;
-
+  return data;
 }
diff --git a/lib/svgo/svg2js.js b/lib/svgo/svg2js.js
index 83f46659..17cf8e15 100644
--- a/lib/svgo/svg2js.js
+++ b/lib/svgo/svg2js.js
@@ -1,19 +1,19 @@
 'use strict';
 
 var SAX = require('@trysound/sax'),
-    JSAPI = require('./jsAPI.js'),
-    CSSClassList = require('./css-class-list'),
-    CSSStyleDeclaration = require('./css-style-declaration'),
-    textElems = require('../../plugins/_collections.js').textElems,
-    entityDeclaration = /<!ENTITY\s+(\S+)\s+(?:'([^']+)'|"([^"]+)")\s*>/g;
+  JSAPI = require('./jsAPI.js'),
+  CSSClassList = require('./css-class-list'),
+  CSSStyleDeclaration = require('./css-style-declaration'),
+  textElems = require('../../plugins/_collections.js').textElems,
+  entityDeclaration = /<!ENTITY\s+(\S+)\s+(?:'([^']+)'|"([^"]+)")\s*>/g;
 
 var config = {
-    strict: true,
-    trim: false,
-    normalize: false,
-    lowercase: true,
-    xmlns: true,
-    position: true
+  strict: true,
+  trim: false,
+  normalize: false,
+  lowercase: true,
+  xmlns: true,
+  position: true,
 };
 
 /**
@@ -21,132 +21,118 @@ var config = {
  *
  * @param {String} data input data
  */
-module.exports = function(data) {
+module.exports = function (data) {
+  var sax = SAX.parser(config.strict, config),
+    root = new JSAPI({ elem: '#document', content: [] }),
+    current = root,
+    stack = [root];
 
-    var sax = SAX.parser(config.strict, config),
-        root = new JSAPI({ elem: '#document', content: [] }),
-        current = root,
-        stack = [root];
+  function pushToContent(content) {
+    content = new JSAPI(content, current);
 
-    function pushToContent(content) {
+    (current.content = current.content || []).push(content);
 
-        content = new JSAPI(content, current);
+    return content;
+  }
 
-        (current.content = current.content || []).push(content);
+  sax.ondoctype = function (doctype) {
+    pushToContent({
+      doctype: doctype,
+    });
 
-        return content;
+    var subsetStart = doctype.indexOf('['),
+      entityMatch;
 
-    }
+    if (subsetStart >= 0) {
+      entityDeclaration.lastIndex = subsetStart;
 
-    sax.ondoctype = function(doctype) {
-
-        pushToContent({
-            doctype: doctype
-        });
-
-        var subsetStart = doctype.indexOf('['),
-            entityMatch;
-
-        if (subsetStart >= 0) {
-            entityDeclaration.lastIndex = subsetStart;
-
-            while ((entityMatch = entityDeclaration.exec(data)) != null) {
-                sax.ENTITIES[entityMatch[1]] = entityMatch[2] || entityMatch[3];
-            }
-        }
-    };
-
-    sax.onprocessinginstruction = function(data) {
-
-        pushToContent({
-            processinginstruction: data
-        });
-
-    };
-
-    sax.oncomment = function(comment) {
-
-        pushToContent({
-            comment: comment.trim()
-        });
-
-    };
-
-    sax.oncdata = function(cdata) {
-
-        pushToContent({
-            cdata: cdata
-        });
-
-    };
-
-    sax.onopentag = function(data) {
-
-        var elem = {
-            elem: data.name,
-            prefix: data.prefix,
-            local: data.local,
-            attrs: {}
-        };
-
-        elem.class = new CSSClassList(elem);
-        elem.style = new CSSStyleDeclaration(elem);
-
-        if (Object.keys(data.attributes).length) {
-            for (const [name, attr] of Object.entries(data.attributes)) {
-
-                if (name === 'class') { // has class attribute
-                    elem.class.hasClass();
-                }
-
-                if (name === 'style') { // has style attribute
-                    elem.style.hasStyle();
-                }
-
-                elem.attrs[name] = {
-                    name: name,
-                    value: attr.value,
-                    prefix: attr.prefix,
-                    local: attr.local
-                };
-            }
-        }
-
-        elem = pushToContent(elem);
-        current = elem;
-
-        stack.push(elem);
-
-    };
-
-    sax.ontext = function(text) {
-      // prevent trimming of meaningful whitespace inside textual tags
-      if (textElems.includes(current.elem) && !data.prefix) {
-        pushToContent({ text: text });
-      } else if (/\S/.test(text)) {
-        pushToContent({ text: text.trim() });
+      while ((entityMatch = entityDeclaration.exec(data)) != null) {
+        sax.ENTITIES[entityMatch[1]] = entityMatch[2] || entityMatch[3];
       }
+    }
+  };
+
+  sax.onprocessinginstruction = function (data) {
+    pushToContent({
+      processinginstruction: data,
+    });
+  };
+
+  sax.oncomment = function (comment) {
+    pushToContent({
+      comment: comment.trim(),
+    });
+  };
+
+  sax.oncdata = function (cdata) {
+    pushToContent({
+      cdata: cdata,
+    });
+  };
+
+  sax.onopentag = function (data) {
+    var elem = {
+      elem: data.name,
+      prefix: data.prefix,
+      local: data.local,
+      attrs: {},
     };
 
-    sax.onclosetag = function() {
-      stack.pop();
-      current = stack[stack.length - 1];
-    };
+    elem.class = new CSSClassList(elem);
+    elem.style = new CSSStyleDeclaration(elem);
 
-    sax.onerror = function(e) {
-
-        e.message = 'Error in parsing SVG: ' + e.message;
-        if (e.message.indexOf('Unexpected end') < 0) {
-            throw e;
+    if (Object.keys(data.attributes).length) {
+      for (const [name, attr] of Object.entries(data.attributes)) {
+        if (name === 'class') {
+          // has class attribute
+          elem.class.hasClass();
         }
 
-    };
+        if (name === 'style') {
+          // has style attribute
+          elem.style.hasStyle();
+        }
 
-    try {
-        sax.write(data).close();
-        return root;
-    } catch (e) {
-        return { error: e.message };
+        elem.attrs[name] = {
+          name: name,
+          value: attr.value,
+          prefix: attr.prefix,
+          local: attr.local,
+        };
+      }
     }
 
+    elem = pushToContent(elem);
+    current = elem;
+
+    stack.push(elem);
+  };
+
+  sax.ontext = function (text) {
+    // prevent trimming of meaningful whitespace inside textual tags
+    if (textElems.includes(current.elem) && !data.prefix) {
+      pushToContent({ text: text });
+    } else if (/\S/.test(text)) {
+      pushToContent({ text: text.trim() });
+    }
+  };
+
+  sax.onclosetag = function () {
+    stack.pop();
+    current = stack[stack.length - 1];
+  };
+
+  sax.onerror = function (e) {
+    e.message = 'Error in parsing SVG: ' + e.message;
+    if (e.message.indexOf('Unexpected end') < 0) {
+      throw e;
+    }
+  };
+
+  try {
+    sax.write(data).close();
+    return root;
+  } catch (e) {
+    return { error: e.message };
+  }
 };
diff --git a/lib/svgo/tools.js b/lib/svgo/tools.js
index 3401a850..ec183209 100644
--- a/lib/svgo/tools.js
+++ b/lib/svgo/tools.js
@@ -7,20 +7,20 @@
  * @param {String} type Data URI type
  * @return {String} output string
  */
-exports.encodeSVGDatauri = function(str, type) {
-    var prefix = 'data:image/svg+xml';
-    if (!type || type === 'base64') {
-        // base64
-        prefix += ';base64,';
-        str = prefix + Buffer.from(str).toString('base64');
-    } else if (type === 'enc') {
-        // URI encoded
-        str = prefix + ',' + encodeURIComponent(str);
-    } else if (type === 'unenc') {
-        // unencoded
-        str = prefix + ',' + str;
-    }
-    return str;
+exports.encodeSVGDatauri = function (str, type) {
+  var prefix = 'data:image/svg+xml';
+  if (!type || type === 'base64') {
+    // base64
+    prefix += ';base64,';
+    str = prefix + Buffer.from(str).toString('base64');
+  } else if (type === 'enc') {
+    // URI encoded
+    str = prefix + ',' + encodeURIComponent(str);
+  } else if (type === 'unenc') {
+    // unencoded
+    str = prefix + ',' + str;
+  }
+  return str;
 };
 
 /**
@@ -29,32 +29,32 @@ exports.encodeSVGDatauri = function(str, type) {
  * @param {string} str input string
  * @return {String} output string
  */
-exports.decodeSVGDatauri = function(str) {
-    var regexp = /data:image\/svg\+xml(;charset=[^;,]*)?(;base64)?,(.*)/;
-    var match = regexp.exec(str);
+exports.decodeSVGDatauri = function (str) {
+  var regexp = /data:image\/svg\+xml(;charset=[^;,]*)?(;base64)?,(.*)/;
+  var match = regexp.exec(str);
 
-    // plain string
-    if (!match) return str;
+  // plain string
+  if (!match) return str;
 
-    var data = match[3];
+  var data = match[3];
 
-    if (match[2]) {
-        // base64
-        str = Buffer.from(data, 'base64').toString('utf8');
-    } else if (data.charAt(0) === '%') {
-        // URI encoded
-        str = decodeURIComponent(data);
-    } else if (data.charAt(0) === '<') {
-        // unencoded
-        str = data;
-    }
-    return str;
+  if (match[2]) {
+    // base64
+    str = Buffer.from(data, 'base64').toString('utf8');
+  } else if (data.charAt(0) === '%') {
+    // URI encoded
+    str = decodeURIComponent(data);
+  } else if (data.charAt(0) === '<') {
+    // unencoded
+    str = data;
+  }
+  return str;
 };
 
-exports.intersectArrays = function(a, b) {
-    return a.filter(function(n) {
-        return b.indexOf(n) > -1;
-    });
+exports.intersectArrays = function (a, b) {
+  return a.filter(function (n) {
+    return b.indexOf(n) > -1;
+  });
 };
 
 /**
@@ -68,48 +68,46 @@ exports.intersectArrays = function(a, b) {
  * @param {string?} command path data instruction
  * @return {string}
  */
-exports.cleanupOutData = function(data, params, command) {
-    var str = '',
-        delimiter,
-        prev;
+exports.cleanupOutData = function (data, params, command) {
+  var str = '',
+    delimiter,
+    prev;
 
-    data.forEach(function(item, i) {
-        // space delimiter by default
-        delimiter = ' ';
+  data.forEach(function (item, i) {
+    // space delimiter by default
+    delimiter = ' ';
 
-        // no extra space in front of first number
-        if (i == 0) delimiter = '';
+    // no extra space in front of first number
+    if (i == 0) delimiter = '';
 
-        // no extra space after 'arcto' command flags(large-arc and sweep flags)
-        // a20 60 45 0 1 30 20 → a20 60 45 0130 20
-        if (params.noSpaceAfterFlags && (command == 'A' || command == 'a')) {
-            var pos = i % 7;
-            if (pos == 4 || pos == 5) delimiter = '';
-        }
+    // no extra space after 'arcto' command flags(large-arc and sweep flags)
+    // a20 60 45 0 1 30 20 → a20 60 45 0130 20
+    if (params.noSpaceAfterFlags && (command == 'A' || command == 'a')) {
+      var pos = i % 7;
+      if (pos == 4 || pos == 5) delimiter = '';
+    }
 
-        // remove floating-point numbers leading zeros
-        // 0.5 → .5
-        // -0.5 → -.5
-        if (params.leadingZero) {
-            item = removeLeadingZero(item);
-        }
+    // remove floating-point numbers leading zeros
+    // 0.5 → .5
+    // -0.5 → -.5
+    if (params.leadingZero) {
+      item = removeLeadingZero(item);
+    }
 
-        // no extra space in front of negative number or
-        // in front of a floating number if a previous number is floating too
-        if (
-            params.negativeExtraSpace &&
-            delimiter != '' &&
-            (item < 0 ||
-                (String(item).charCodeAt(0) == 46 && prev % 1 !== 0)
-            )
-        ) {
-            delimiter = '';
-        }
-        // save prev item value
-        prev = item;
-        str += delimiter + item;
-    });
-    return str;
+    // no extra space in front of negative number or
+    // in front of a floating number if a previous number is floating too
+    if (
+      params.negativeExtraSpace &&
+      delimiter != '' &&
+      (item < 0 || (String(item).charCodeAt(0) == 46 && prev % 1 !== 0))
+    ) {
+      delimiter = '';
+    }
+    // save prev item value
+    prev = item;
+    str += delimiter + item;
+  });
+  return str;
 };
 
 /**
@@ -125,13 +123,14 @@ exports.cleanupOutData = function(data, params, command) {
  *
  * @return {String} output number as string
  */
-var removeLeadingZero = exports.removeLeadingZero = function(num) {
-    var strNum = num.toString();
+var removeLeadingZero = function (num) {
+  var strNum = num.toString();
 
-    if (0 < num && num < 1 && strNum.charCodeAt(0) == 48) {
-        strNum = strNum.slice(1);
-    } else if (-1 < num && num < 0 && strNum.charCodeAt(1) == 48) {
-        strNum = strNum.charAt(0) + strNum.slice(2);
-    }
-    return strNum;
+  if (0 < num && num < 1 && strNum.charCodeAt(0) == 48) {
+    strNum = strNum.slice(1);
+  } else if (-1 < num && num < 0 && strNum.charCodeAt(1) == 48) {
+    strNum = strNum.charAt(0) + strNum.slice(2);
+  }
+  return strNum;
 };
+exports.removeLeadingZero = removeLeadingZero;