diff --git a/lib/svgo/svg2js.js b/lib/parser.js
similarity index 54%
rename from lib/svgo/svg2js.js
rename to lib/parser.js
index 3d6e8862..79357c31 100644
--- a/lib/svgo/svg2js.js
+++ b/lib/parser.js
@@ -1,10 +1,30 @@
 'use strict';
 
+/**
+ * @typedef {import('./types').XastNode} XastNode
+ * @typedef {import('./types').XastInstruction} XastInstruction
+ * @typedef {import('./types').XastDoctype} XastDoctype
+ * @typedef {import('./types').XastComment} XastComment
+ * @typedef {import('./types').XastRoot} XastRoot
+ * @typedef {import('./types').XastElement} XastElement
+ * @typedef {import('./types').XastCdata} XastCdata
+ * @typedef {import('./types').XastText} XastText
+ * @typedef {import('./types').XastParent} XastParent
+ */
+
+// @ts-ignore sax will be replaced with something else later
 const SAX = require('@trysound/sax');
-const JSAPI = require('./jsAPI.js');
-const { textElems } = require('../../plugins/_collections.js');
+const JSAPI = require('./svgo/jsAPI.js');
+const { textElems } = require('../plugins/_collections.js');
 
 class SvgoParserError extends Error {
+  /**
+   * @param message {string}
+   * @param line {number}
+   * @param column {number}
+   * @param source {string}
+   * @param file {void | string}
+   */
   constructor(message, line, column, source, file) {
     super(message);
     this.name = 'SvgoParserError';
@@ -67,103 +87,160 @@ const config = {
 /**
  * Convert SVG (XML) string to SVG-as-JS object.
  *
- * @param {String} data input data
+ * @type {(data: string, from?: string) => XastRoot}
  */
-module.exports = function (data, from) {
+const parseSvg = (data, from) => {
   const sax = SAX.parser(config.strict, config);
+  /**
+   * @type {XastRoot}
+   */
   const root = new JSAPI({ type: 'root', children: [] });
+  /**
+   * @type {XastParent}
+   */
   let current = root;
-  let stack = [root];
+  /**
+   * @type {Array<XastParent>}
+   */
+  const stack = [root];
 
-  function pushToContent(node) {
+  /**
+   * @type {<T extends XastNode>(node: T) => T}
+   */
+  const pushToContent = (node) => {
     const wrapped = new JSAPI(node, current);
     current.children.push(wrapped);
     return wrapped;
-  }
+  };
 
-  sax.ondoctype = function (doctype) {
-    pushToContent({
+  /**
+   * @type {(doctype: string) => void}
+   */
+  sax.ondoctype = (doctype) => {
+    /**
+     * @type {XastDoctype}
+     */
+    const node = {
       type: 'doctype',
       // TODO parse doctype for name, public and system to match xast
       name: 'svg',
       data: {
         doctype,
       },
-    });
-
+    };
+    pushToContent(node);
     const subsetStart = doctype.indexOf('[');
-    let entityMatch;
-
     if (subsetStart >= 0) {
       entityDeclaration.lastIndex = subsetStart;
-
-      while ((entityMatch = entityDeclaration.exec(data)) != null) {
+      let entityMatch = entityDeclaration.exec(data);
+      while (entityMatch != null) {
         sax.ENTITIES[entityMatch[1]] = entityMatch[2] || entityMatch[3];
+        entityMatch = entityDeclaration.exec(data);
       }
     }
   };
 
-  sax.onprocessinginstruction = function (data) {
-    pushToContent({
+  /**
+   * @type {(data: { name: string, body: string }) => void}
+   */
+  sax.onprocessinginstruction = (data) => {
+    /**
+     * @type {XastInstruction}
+     */
+    const node = {
       type: 'instruction',
       name: data.name,
       value: data.body,
-    });
+    };
+    pushToContent(node);
   };
 
-  sax.oncomment = function (comment) {
-    pushToContent({
+  /**
+   * @type {(comment: string) => void}
+   */
+  sax.oncomment = (comment) => {
+    /**
+     * @type {XastComment}
+     */
+    const node = {
       type: 'comment',
       value: comment.trim(),
-    });
+    };
+    pushToContent(node);
   };
 
-  sax.oncdata = function (cdata) {
-    pushToContent({
+  /**
+   * @type {(cdata: string) => void}
+   */
+  sax.oncdata = (cdata) => {
+    /**
+     * @type {XastCdata}
+     */
+    const node = {
       type: 'cdata',
       value: cdata,
-    });
+    };
+    pushToContent(node);
   };
 
-  sax.onopentag = function (data) {
-    var element = {
+  /**
+   * @type {(data: { name: string, attributes: Record<string, { value: string }>}) => void}
+   */
+  sax.onopentag = (data) => {
+    /**
+     * @type {XastElement}
+     */
+    let element = {
       type: 'element',
       name: data.name,
       attributes: {},
       children: [],
     };
-
     for (const [name, attr] of Object.entries(data.attributes)) {
       element.attributes[name] = attr.value;
     }
-
     element = pushToContent(element);
     current = element;
-
     stack.push(element);
   };
 
-  sax.ontext = function (text) {
-    // prevent trimming of meaningful whitespace inside textual tags
-    if (textElems.includes(current.name) && !data.prefix) {
-      pushToContent({
-        type: 'text',
-        value: text,
-      });
-    } else if (/\S/.test(text)) {
-      pushToContent({
-        type: 'text',
-        value: text.trim(),
-      });
+  /**
+   * @type {(text: string) => void}
+   */
+  sax.ontext = (text) => {
+    if (current.type === 'element') {
+      // prevent trimming of meaningful whitespace inside textual tags
+      if (textElems.includes(current.name)) {
+        /**
+         * @type {XastText}
+         */
+        const node = {
+          type: 'text',
+          value: text,
+        };
+        pushToContent(node);
+      } else if (/\S/.test(text)) {
+        /**
+         * @type {XastText}
+         */
+        const node = {
+          type: 'text',
+          value: text.trim(),
+        };
+        pushToContent(node);
+      }
     }
   };
 
-  sax.onclosetag = function () {
+  sax.onclosetag = () => {
     stack.pop();
     current = stack[stack.length - 1];
   };
 
-  sax.onerror = function (e) {
+  /**
+   * @type {(e: any) => void}
+   */
+  sax.onerror = (e) => {
     const error = new SvgoParserError(
       e.reason,
       e.line + 1,
@@ -179,3 +256,4 @@ module.exports = function (data, from) {
   sax.write(data).close();
   return root;
 };
+exports.parseSvg = parseSvg;
diff --git a/lib/style.test.js b/lib/style.test.js
index fdb191b4..11669d0b 100644
--- a/lib/style.test.js
+++ b/lib/style.test.js
@@ -7,7 +7,7 @@
 
 const { collectStylesheet, computeStyle } = require('./style.js');
 const { visit } = require('./xast.js');
-const svg2js = require('./svgo/svg2js.js');
+const { parseSvg } = require('./parser.js');
 
 /**
  * @type {(node: XastParent, id: string) => XastElement}
@@ -33,7 +33,7 @@ const getElementById = (node, id) => {
 };
 
 it('collects styles', () => {
-  const root = svg2js(`
+  const root = parseSvg(`
       <svg>
         <rect id="class" class="a" />
         <rect id="two-classes" class="b a" />
@@ -88,7 +88,7 @@ it('collects styles', () => {
 });
 
 it('prioritizes different kinds of styles', () => {
-  const root = svg2js(`
+  const root = parseSvg(`
       <svg>
         <style>
           g > .a { fill: red; }
@@ -130,7 +130,7 @@ it('prioritizes different kinds of styles', () => {
 });
 
 it('prioritizes important styles', () => {
-  const root = svg2js(`
+  const root = parseSvg(`
       <svg>
         <style>
           g > .a { fill: red; }
@@ -166,7 +166,7 @@ it('prioritizes important styles', () => {
 });
 
 it('treats at-rules and pseudo-classes as dynamic styles', () => {
-  const root = svg2js(`
+  const root = parseSvg(`
       <svg>
         <style>
           @media screen {
@@ -208,7 +208,7 @@ it('treats at-rules and pseudo-classes as dynamic styles', () => {
 });
 
 it('considers <style> media attribute', () => {
-  const root = svg2js(`
+  const root = parseSvg(`
       <svg>
         <style media="print">
           @media screen {
@@ -241,7 +241,7 @@ it('considers <style> media attribute', () => {
 });
 
 it('ignores <style> with invalid type', () => {
-  const root = svg2js(`
+  const root = parseSvg(`
       <svg>
         <style type="text/css">
           .a { fill: red; }
@@ -270,7 +270,7 @@ it('ignores <style> with invalid type', () => {
 });
 
 it('ignores keyframes atrule', () => {
-  const root = svg2js(`
+  const root = parseSvg(`
       <svg>
         <style>
           .a {
diff --git a/lib/svgo.js b/lib/svgo.js
index d29213fb..599bf53e 100644
--- a/lib/svgo.js
+++ b/lib/svgo.js
@@ -5,7 +5,7 @@ const {
   resolvePluginConfig,
   extendDefaultPlugins,
 } = require('./svgo/config.js');
-const svg2js = require('./svgo/svg2js.js');
+const { parseSvg } = require('./parser.js');
 const js2svg = require('./svgo/js2svg.js');
 const { invokePlugins } = require('./svgo/plugins.js');
 const JSAPI = require('./svgo/jsAPI.js');
@@ -31,7 +31,7 @@ const optimize = (input, config) => {
     info.multipassCount = i;
     // TODO throw this error in v3
     try {
-      svgjs = svg2js(input, config.path);
+      svgjs = parseSvg(input, config.path);
     } catch (error) {
       return { error: error.toString(), modernError: error };
     }
diff --git a/lib/svgo/svg2js.d.ts b/lib/svgo/svg2js.d.ts
deleted file mode 100644
index a11ba35f..00000000
--- a/lib/svgo/svg2js.d.ts
+++ /dev/null
@@ -1,2 +0,0 @@
-declare let obj: any;
-export = obj;
diff --git a/lib/types.ts b/lib/types.ts
index 32cdcbc7..b62145a3 100644
--- a/lib/types.ts
+++ b/lib/types.ts
@@ -1,4 +1,4 @@
-type XastDoctype = {
+export type XastDoctype = {
   type: 'doctype';
   name: string;
   data: {
@@ -6,23 +6,23 @@ type XastDoctype = {
   };
 };
 
-type XastInstruction = {
+export type XastInstruction = {
   type: 'instruction';
   name: string;
   value: string;
 };
 
-type XastComment = {
+export type XastComment = {
   type: 'comment';
   value: string;
 };
 
-type XastCdata = {
+export type XastCdata = {
   type: 'cdata';
   value: string;
 };
 
-type XastText = {
+export type XastText = {
   type: 'text';
   value: string;
 };
diff --git a/test/svg2js/_index.test.js b/test/svg2js/_index.test.js
index dabd7efa..4c48db83 100644
--- a/test/svg2js/_index.test.js
+++ b/test/svg2js/_index.test.js
@@ -5,7 +5,7 @@ const PATH = require('path');
 const JSAPI = require('../../lib/svgo/jsAPI');
 const CSSClassList = require('../../lib/svgo/css-class-list');
 const CSSStyleDeclaration = require('../../lib/svgo/css-style-declaration');
-const SVG2JS = require('../../lib/svgo/svg2js');
+const { parseSvg } = require('../../lib/parser.js');
 
 describe('svg2js', function () {
   describe('working svg', function () {
@@ -18,7 +18,7 @@ describe('svg2js', function () {
           throw err;
         }
 
-        root = SVG2JS(data);
+        root = parseSvg(data);
         done();
       });
     });
diff --git a/tsconfig.json b/tsconfig.json
index 5e36786c..d757d054 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -11,6 +11,7 @@
   },
   "include": [
     "plugins/**/*",
+    "lib/svg-parser.js",
     "lib/xast.test.js",
     "lib/path.test.js",
     "lib/style.test.js",