Refactor inlineStyles (#1601)

This is a big one

- got rid from another closestByName usage
- delegated removing empty defs elements to removeEmptyContainers plugin
- got rid from all css-tools usages (most inlineStyles code was there
  for some reason)
- combined a few loops
- fixed useMqs option (I would remove it in v3 for simplicity as it
  seems nobody use it)

plugins/inlineStyles.js

@@ -1,24 +1,43 @@
 'use strict';
 
+/**
+ * @typedef {import('../lib/types').Specificity} Specificity
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').XastParent} XastParent
+ */
+
 const csstree = require('css-tree');
-const { querySelectorAll, closestByName } = require('../lib/xast.js');
+// @ts-ignore not defined in @types/csso
-const cssTools = require('../lib/css-tools');
+const specificity = require('csso/lib/restructure/prepare/specificity');
+const stable = require('stable');
+const {
+  visitSkip,
+  querySelectorAll,
+  detachNodeFromParent,
+} = require('../lib/xast.js');
 
+exports.type = 'visitor';
 exports.name = 'inlineStyles';
-
-exports.type = 'full';
-
 exports.active = true;
-
-exports.params = {
-  onlyMatchedOnce: true,
-  removeMatchedSelectors: true,
-  useMqs: ['', 'screen'],
-  usePseudos: [''],
-};
-
 exports.description = 'inline styles (additional options)';
 
+/**
+ * Compares two selector specificities.
+ * extracted from https://github.com/keeganstreet/specificity/blob/master/specificity.js#L211
+ *
+ * @type {(a: Specificity, b: Specificity) => number}
+ */
+const compareSpecificity = (a, b) => {
+  for (var i = 0; i < 4; i += 1) {
+    if (a[i] < b[i]) {
+      return -1;
+    } else if (a[i] > b[i]) {
+      return 1;
+    }
+  }
+  return 0;
+};
+
 /**
  * Moves + merges styles from style elements to element styles
  *
@@ -38,267 +57,323 @@ exports.description = 'inline styles (additional options)';
  *     what pseudo-classes/-elements to be used
  *     empty string element for all non-pseudo-classes and/or -elements
  *
- * @param {Object} root document element
- * @param {Object} opts plugin params
- *
  * @author strarsis <strarsis@gmail.com>
+ *
+ * @type {import('../lib/types').Plugin<{
+ *   onlyMatchedOnce?: boolean,
+ *   removeMatchedSelectors?: boolean,
+ *   useMqs?: Array<string>,
+ *   usePseudos?: Array<string>
+ * }>}
  */
-exports.fn = function (root, opts) {
+exports.fn = (root, params) => {
-  // collect <style/>s
+  const {
-  var styleEls = querySelectorAll(root, 'style');
+    onlyMatchedOnce = true,
+    removeMatchedSelectors = true,
+    useMqs = ['', 'screen'],
+    usePseudos = [''],
+  } = params;
 
-  //no <styles/>s, nothing to do
+  /**
-  if (styleEls.length === 0) {
+   * @type {Array<{ node: XastElement, parentNode: XastParent, cssAst: csstree.StyleSheet }>}
-    return root;
+   */
-  }
+  const styles = [];
+  /**
+   * @type {Array<{
+   *   node: csstree.Selector,
+   *   item: csstree.ListItem<csstree.CssNode>,
+   *   rule: csstree.Rule,
+   *   matchedElements?: Array<XastElement>
+   * }>}
+   */
+  let selectors = [];
 
-  var styles = [],
+  return {
-    selectors = [];
+    element: {
-
+      enter: (node, parentNode) => {
-  for (var styleEl of styleEls) {
+        // skip <foreignObject /> content
-    // values other than the empty string or text/css are not used
+        if (node.name === 'foreignObject') {
-    if (
+          return visitSkip;
-      styleEl.attributes.type != null &&
-      styleEl.attributes.type !== '' &&
-      styleEl.attributes.type !== 'text/css'
-    ) {
-      continue;
-    }
-    // skip empty <style/>s or <foreignObject> content.
-    if (
-      styleEl.children.length === 0 ||
-      closestByName(styleEl, 'foreignObject')
-    ) {
-      continue;
-    }
-
-    var cssStr = cssTools.getCssStr(styleEl);
-
-    // collect <style/>s and their css ast
-    var cssAst = {};
-    try {
-      cssAst = csstree.parse(cssStr, {
-        parseValue: false,
-        parseCustomProperty: false,
-      });
-    } catch (parseError) {
-      // console.warn('Warning: Parse error of styles of <style/> element, skipped. Error details: ' + parseError);
-      continue;
-    }
-
-    styles.push({
-      styleEl: styleEl,
-      cssAst: cssAst,
-    });
-
-    selectors = selectors.concat(cssTools.flattenToSelectors(cssAst));
-  }
-
-  // filter for mediaqueries to be used or without any mediaquery
-  var selectorsMq = cssTools.filterByMqs(selectors, opts.useMqs);
-
-  // filter for pseudo elements to be used
-  var selectorsPseudo = cssTools.filterByPseudos(selectorsMq, opts.usePseudos);
-
-  // remove PseudoClass from its SimpleSelector for proper matching
-  cssTools.cleanPseudos(selectorsPseudo);
-
-  // stable sort selectors
-  var sortedSelectors = cssTools.sortSelectors(selectorsPseudo).reverse();
-
-  var selector, selectedEl;
-
-  // match selectors
-  for (selector of sortedSelectors) {
-    var selectorStr = csstree.generate(selector.item.data),
-      selectedEls = null;
-
-    try {
-      selectedEls = querySelectorAll(root, selectorStr);
-    } catch (selectError) {
-      // console.warn('Warning: Syntax error when trying to select \n\n' + selectorStr + '\n\n, skipped. Error details: ' + selectError);
-      continue;
-    }
-
-    if (selectedEls.length === 0) {
-      // nothing selected
-      continue;
-    }
-
-    selector.selectedEls = selectedEls;
-  }
-
-  // apply <style/> styles to matched elements
-  for (selector of sortedSelectors) {
-    if (!selector.selectedEls) {
-      continue;
-    }
-
-    if (
-      opts.onlyMatchedOnce &&
-      selector.selectedEls !== null &&
-      selector.selectedEls.length > 1
-    ) {
-      // skip selectors that match more than once if option onlyMatchedOnce is enabled
-      continue;
-    }
-
-    // apply <style/> to matched elements
-    for (selectedEl of selector.selectedEls) {
-      if (selector.rule === null) {
-        continue;
-      }
-      const styleDeclarationList = csstree.parse(
-        selectedEl.attributes.style == null ? '' : selectedEl.attributes.style,
-        {
-          context: 'declarationList',
-          parseValue: false,
         }
-      );
+        // collect only non-empty <style /> elements
-      const styleDeclarationItems = new Map();
+        if (node.name !== 'style' || node.children.length === 0) {
-      csstree.walk(styleDeclarationList, {
+          return;
-        visit: 'Declaration',
-        enter(node, item) {
-          styleDeclarationItems.set(node.property, item);
-        },
-      });
-      // merge declarations
-      csstree.walk(selector.rule, {
-        visit: 'Declaration',
-        enter(ruleDeclaration) {
-          // existing inline styles have higher priority
-          // no inline styles, external styles,                                    external styles used
-          // inline styles,    external styles same   priority as inline styles,   inline   styles used
-          // inline styles,    external styles higher priority than inline styles, external styles used
-          const matchedItem = styleDeclarationItems.get(
-            ruleDeclaration.property
-          );
-          const ruleDeclarationItem =
-            styleDeclarationList.children.createItem(ruleDeclaration);
-          if (matchedItem == null) {
-            styleDeclarationList.children.append(ruleDeclarationItem);
-          } else if (
-            matchedItem.data.important !== true &&
-            ruleDeclaration.important === true
-          ) {
-            styleDeclarationList.children.replace(
-              matchedItem,
-              ruleDeclarationItem
-            );
-            styleDeclarationItems.set(
-              ruleDeclaration.property,
-              ruleDeclarationItem
-            );
-          }
-        },
-      });
-      selectedEl.attributes.style = csstree.generate(styleDeclarationList);
-    }
-
-    if (
-      opts.removeMatchedSelectors &&
-      selector.selectedEls !== null &&
-      selector.selectedEls.length > 0
-    ) {
-      // clean up matching simple selectors if option removeMatchedSelectors is enabled
-      selector.rule.prelude.children.remove(selector.item);
-    }
-  }
-
-  if (!opts.removeMatchedSelectors) {
-    return root; // no further processing required
-  }
-
-  // clean up matched class + ID attribute values
-  for (selector of sortedSelectors) {
-    if (!selector.selectedEls) {
-      continue;
-    }
-
-    if (
-      opts.onlyMatchedOnce &&
-      selector.selectedEls !== null &&
-      selector.selectedEls.length > 1
-    ) {
-      // skip selectors that match more than once if option onlyMatchedOnce is enabled
-      continue;
-    }
-
-    for (selectedEl of selector.selectedEls) {
-      // class
-      const classList = new Set(
-        selectedEl.attributes.class == null
-          ? null
-          : selectedEl.attributes.class.split(' ')
-      );
-      const firstSubSelector = selector.item.data.children.first();
-      if (firstSubSelector.type === 'ClassSelector') {
-        classList.delete(firstSubSelector.name);
-      }
-      if (classList.size === 0) {
-        delete selectedEl.attributes.class;
-      } else {
-        selectedEl.attributes.class = Array.from(classList).join(' ');
-      }
-
-      // ID
-      if (firstSubSelector.type === 'IdSelector') {
-        if (selectedEl.attributes.id === firstSubSelector.name) {
-          delete selectedEl.attributes.id;
         }
-      }
+        // values other than the empty string or text/css are not used
-    }
-  }
-
-  // clean up now empty elements
-  for (var style of styles) {
-    csstree.walk(style.cssAst, {
-      visit: 'Rule',
-      enter: function (node, item, list) {
-        // clean up <style/> atrules without any rulesets left
         if (
-          node.type === 'Atrule' &&
+          node.attributes.type != null &&
-          // only Atrules containing rulesets
+          node.attributes.type !== '' &&
-          node.block !== null &&
+          node.attributes.type !== 'text/css'
-          node.block.children.isEmpty()
         ) {
-          list.remove(item);
+          return;
+        }
+        // parse css in style element
+        let cssText = '';
+        for (const child of node.children) {
+          if (child.type === 'text' || child.type === 'cdata') {
+            cssText += child.value;
+          }
+        }
+        /**
+         * @type {null | csstree.CssNode}
+         */
+        let cssAst = null;
+        try {
+          cssAst = csstree.parse(cssText, {
+            parseValue: false,
+            parseCustomProperty: false,
+          });
+        } catch {
+          return;
+        }
+        if (cssAst.type === 'StyleSheet') {
+          styles.push({ node, parentNode, cssAst });
+        }
+
+        // collect selectors
+        csstree.walk(cssAst, {
+          visit: 'Selector',
+          enter(node, item) {
+            const atrule = this.atrule;
+            const rule = this.rule;
+            if (rule == null) {
+              return;
+            }
+
+            // skip media queries not included into useMqs param
+            let mq = '';
+            if (atrule != null) {
+              mq = atrule.name;
+              if (atrule.prelude != null) {
+                mq += ` ${csstree.generate(atrule.prelude)}`;
+              }
+            }
+            if (useMqs.includes(mq) === false) {
+              return;
+            }
+
+            /**
+             * @type {Array<{
+             *   item: csstree.ListItem<csstree.CssNode>,
+             *   list: csstree.List<csstree.CssNode>
+             * }>}
+             */
+            const pseudos = [];
+            if (node.type === 'Selector') {
+              node.children.each((childNode, childItem, childList) => {
+                if (
+                  childNode.type === 'PseudoClassSelector' ||
+                  childNode.type === 'PseudoElementSelector'
+                ) {
+                  pseudos.push({ item: childItem, list: childList });
+                }
+              });
+            }
+
+            // skip pseudo classes and pseudo elements not includes into usePseudos param
+            const pseudoSelectors = csstree.generate({
+              type: 'Selector',
+              children: new csstree.List().fromArray(
+                pseudos.map((pseudo) => pseudo.item.data)
+              ),
+            });
+            if (usePseudos.includes(pseudoSelectors) === false) {
+              return;
+            }
+
+            // remove pseudo classes and elements to allow querySelector match elements
+            // TODO this is not very accurate since some pseudo classes like first-child
+            // are used for selection
+            for (const pseudo of pseudos) {
+              pseudo.list.remove(pseudo.item);
+            }
+
+            selectors.push({ node, item, rule });
+          },
+        });
+      },
+    },
+
+    root: {
+      exit: () => {
+        if (styles.length === 0) {
+          return;
+        }
+        // stable sort selectors
+        const sortedSelectors = stable(selectors, (a, b) => {
+          const aSpecificity = specificity(a.item.data);
+          const bSpecificity = specificity(b.item.data);
+          return compareSpecificity(aSpecificity, bSpecificity);
+        }).reverse();
+
+        for (const selector of sortedSelectors) {
+          // match selectors
+          const selectorText = csstree.generate(selector.item.data);
+          /**
+           * @type {Array<XastElement>}
+           */
+          const matchedElements = [];
+          try {
+            for (const node of querySelectorAll(root, selectorText)) {
+              if (node.type === 'element') {
+                matchedElements.push(node);
+              }
+            }
+          } catch (selectError) {
+            continue;
+          }
+          // nothing selected
+          if (matchedElements.length === 0) {
+            continue;
+          }
+
+          // apply styles to matched elements
+          // skip selectors that match more than once if option onlyMatchedOnce is enabled
+          if (onlyMatchedOnce && matchedElements.length > 1) {
+            continue;
+          }
+
+          // apply <style/> to matched elements
+          for (const selectedEl of matchedElements) {
+            const styleDeclarationList = csstree.parse(
+              selectedEl.attributes.style == null
+                ? ''
+                : selectedEl.attributes.style,
+              {
+                context: 'declarationList',
+                parseValue: false,
+              }
+            );
+            if (styleDeclarationList.type !== 'DeclarationList') {
+              continue;
+            }
+            const styleDeclarationItems = new Map();
+            csstree.walk(styleDeclarationList, {
+              visit: 'Declaration',
+              enter(node, item) {
+                styleDeclarationItems.set(node.property, item);
+              },
+            });
+            // merge declarations
+            csstree.walk(selector.rule, {
+              visit: 'Declaration',
+              enter(ruleDeclaration) {
+                // existing inline styles have higher priority
+                // no inline styles, external styles,                                    external styles used
+                // inline styles,    external styles same   priority as inline styles,   inline   styles used
+                // inline styles,    external styles higher priority than inline styles, external styles used
+                const matchedItem = styleDeclarationItems.get(
+                  ruleDeclaration.property
+                );
+                const ruleDeclarationItem =
+                  styleDeclarationList.children.createItem(ruleDeclaration);
+                if (matchedItem == null) {
+                  styleDeclarationList.children.append(ruleDeclarationItem);
+                } else if (
+                  matchedItem.data.important !== true &&
+                  ruleDeclaration.important === true
+                ) {
+                  styleDeclarationList.children.replace(
+                    matchedItem,
+                    ruleDeclarationItem
+                  );
+                  styleDeclarationItems.set(
+                    ruleDeclaration.property,
+                    ruleDeclarationItem
+                  );
+                }
+              },
+            });
+            selectedEl.attributes.style =
+              csstree.generate(styleDeclarationList);
+          }
+
+          if (
+            removeMatchedSelectors &&
+            matchedElements.length !== 0 &&
+            selector.rule.prelude.type === 'SelectorList'
+          ) {
+            // clean up matching simple selectors if option removeMatchedSelectors is enabled
+            selector.rule.prelude.children.remove(selector.item);
+          }
+          selector.matchedElements = matchedElements;
+        }
+
+        // no further processing required
+        if (removeMatchedSelectors === false) {
           return;
         }
 
-        // clean up <style/> rulesets without any css selectors left
+        // clean up matched class + ID attribute values
-        if (node.type === 'Rule' && node.prelude.children.isEmpty()) {
+        for (const selector of sortedSelectors) {
-          list.remove(item);
+          if (selector.matchedElements == null) {
+            continue;
+          }
+
+          if (onlyMatchedOnce && selector.matchedElements.length > 1) {
+            // skip selectors that match more than once if option onlyMatchedOnce is enabled
+            continue;
+          }
+
+          for (const selectedEl of selector.matchedElements) {
+            // class
+            const classList = new Set(
+              selectedEl.attributes.class == null
+                ? null
+                : selectedEl.attributes.class.split(' ')
+            );
+            const firstSubSelector = selector.node.children.first();
+            if (
+              firstSubSelector != null &&
+              firstSubSelector.type === 'ClassSelector'
+            ) {
+              classList.delete(firstSubSelector.name);
+            }
+            if (classList.size === 0) {
+              delete selectedEl.attributes.class;
+            } else {
+              selectedEl.attributes.class = Array.from(classList).join(' ');
+            }
+
+            // ID
+            if (
+              firstSubSelector != null &&
+              firstSubSelector.type === 'IdSelector'
+            ) {
+              if (selectedEl.attributes.id === firstSubSelector.name) {
+                delete selectedEl.attributes.id;
+              }
+            }
+          }
+        }
+
+        for (const style of styles) {
+          csstree.walk(style.cssAst, {
+            visit: 'Rule',
+            enter: function (node, item, list) {
+              // clean up <style/> rulesets without any css selectors left
+              if (
+                node.type === 'Rule' &&
+                node.prelude.type === 'SelectorList' &&
+                node.prelude.children.isEmpty()
+              ) {
+                list.remove(item);
+              }
+            },
+          });
+
+          if (style.cssAst.children.isEmpty()) {
+            // remove emtpy style element
+            detachNodeFromParent(style.node, style.parentNode);
+          } else {
+            // update style element if any styles left
+            const firstChild = style.node.children[0];
+            if (firstChild.type === 'text' || firstChild.type === 'cdata') {
+              firstChild.value = csstree.generate(style.cssAst);
+            }
+          }
         }
       },
-    });
+    },
-
+  };
-    if (style.cssAst.children.isEmpty()) {
-      // clean up now emtpy <style/>s
-      var styleParentEl = style.styleEl.parentNode;
-      styleParentEl.spliceContent(
-        styleParentEl.children.indexOf(style.styleEl),
-        1
-      );
-
-      if (
-        styleParentEl.name === 'defs' &&
-        styleParentEl.children.length === 0
-      ) {
-        // also clean up now empty <def/>s
-        var defsParentEl = styleParentEl.parentNode;
-        defsParentEl.spliceContent(
-          defsParentEl.children.indexOf(styleParentEl),
-          1
-        );
-      }
-
-      continue;
-    }
-
-    // update existing, left over <style>s
-    cssTools.setCssStr(style.styleEl, csstree.generate(style.cssAst));
-  }
-
-  return root;
 };

test/plugins/inlineStyles.14.svg

@@ -19,10 +19,10 @@
 <svg id="test" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 81.285 81.285">
     <defs>
         <style>
-            @media only screen and (min-device-width:320px) and (max-device-width:480px) and (-webkit-min-device-pixel-ratio:2){.blue{fill:blue}}
+            @media only screen and (min-device-width:320px) and (max-device-width:480px) and (-webkit-min-device-pixel-ratio:2){}
         </style>
     </defs>
-    <rect width="100" height="100" class="blue"/>
+    <rect width="100" height="100" style="fill:blue"/>
 </svg>
 
 @@@

test/plugins/inlineStyles.16.svg

@@ -25,6 +25,7 @@
 @@@
 
 <svg id="Ebene_1" data-name="Ebene 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 222 57.28">
+    <defs/>
     <title>button</title>
     <rect width="222" height="57.28" rx="28.64" ry="28.64" style="stroke:red;fill:#37d0cd"/>
     <path d="M312.75,168.66A2.15,2.15,0,0,1,311.2,165L316,160l-4.8-5a2.15,2.15,0,1,1,3.1-3l6.21,6.49a2.15,2.15,0,0,1,0,3L314.31,168a2.14,2.14,0,0,1-1.56.67Zm0,0" transform="translate(-119 -131.36)" style="fill:#fff"/>

tsconfig.json

@@ -29,7 +29,6 @@
     "plugins/removeDimensions.js",
     "plugins/removeNonInheritableGroupAttrs.js",
     "plugins/removeXMLNS.js",
-    "plugins/inlineStyles.js",
     "plugins/preset-default.js"
   ]
 }