From 59796a829beb4ac7c0291e10e75fa9445ae91aff Mon Sep 17 00:00:00 2001
From: Jon Dufresne <jon.dufresne@gmail.com>
Date: Mon, 15 Jan 2024 13:48:14 -0800
Subject: [PATCH] feat(removeDeprecatedAttrs): new removeDeprecatedAttrs plugin
 (#1869)

---
 docs/03-plugins/remove-deprecated-attrs.mdx   |  27 ++++
 lib/builtin.js                                |   2 +
 plugins/_collections.js                       | 102 +++++++++++++++
 plugins/plugins-types.d.ts                    |   3 +
 plugins/preset-default.js                     |   2 +
 plugins/removeDeprecatedAttrs.js              | 120 ++++++++++++++++++
 test/plugins/_collections.test.js             |  24 ++++
 test/plugins/removeDeprecatedAttrs.01.svg.txt |  13 ++
 test/plugins/removeDeprecatedAttrs.02.svg.txt |  13 ++
 test/plugins/removeDeprecatedAttrs.03.svg.txt |  17 +++
 test/plugins/removeDeprecatedAttrs.04.svg.txt |  27 ++++
 test/plugins/removeDeprecatedAttrs.05.svg.txt |  13 ++
 test/plugins/removeDeprecatedAttrs.06.svg.txt |  13 ++
 test/plugins/removeDeprecatedAttrs.07.svg.txt |  17 +++
 test/plugins/removeDeprecatedAttrs.08.svg.txt |  23 ++++
 15 files changed, 416 insertions(+)
 create mode 100644 docs/03-plugins/remove-deprecated-attrs.mdx
 create mode 100644 plugins/removeDeprecatedAttrs.js
 create mode 100644 test/plugins/_collections.test.js
 create mode 100644 test/plugins/removeDeprecatedAttrs.01.svg.txt
 create mode 100644 test/plugins/removeDeprecatedAttrs.02.svg.txt
 create mode 100644 test/plugins/removeDeprecatedAttrs.03.svg.txt
 create mode 100644 test/plugins/removeDeprecatedAttrs.04.svg.txt
 create mode 100644 test/plugins/removeDeprecatedAttrs.05.svg.txt
 create mode 100644 test/plugins/removeDeprecatedAttrs.06.svg.txt
 create mode 100644 test/plugins/removeDeprecatedAttrs.07.svg.txt
 create mode 100644 test/plugins/removeDeprecatedAttrs.08.svg.txt

diff --git a/docs/03-plugins/remove-deprecated-attrs.mdx b/docs/03-plugins/remove-deprecated-attrs.mdx
new file mode 100644
index 000000000..a294f2006
--- /dev/null
+++ b/docs/03-plugins/remove-deprecated-attrs.mdx
@@ -0,0 +1,27 @@
+---
+title: Remove Deprecated Attributes
+svgo:
+  pluginId: removeDeprecatedAttrs
+  defaultPlugin: true
+  parameters:
+    removeAny:
+      description: By default, this plugin only removes safe deprecated attributes that do not change the rendered image. Enabling this will remove all deprecated attributes which may impact rendering.
+      type: boolean
+      default: false
+---
+
+Removes deprecated attributes from elements in the document.
+
+This plugin does not remove attributes from the deprecated XLink namespace. To remove them, use the [Remove XLink](/docs/plugins/remove-xlink/) plugin.
+
+## Usage
+
+<PluginUsage />
+
+## Demo
+
+<PluginDemo />
+
+## Implementation
+
+- https://github.com/svg/svgo/blob/main/plugins/removeDeprecatedAttrs.js
diff --git a/lib/builtin.js b/lib/builtin.js
index 7e7639758..57e8bae64 100644
--- a/lib/builtin.js
+++ b/lib/builtin.js
@@ -24,6 +24,7 @@ import * as prefixIds from '../plugins/prefixIds.js';
 import * as removeAttributesBySelector from '../plugins/removeAttributesBySelector.js';
 import * as removeAttrs from '../plugins/removeAttrs.js';
 import * as removeComments from '../plugins/removeComments.js';
+import * as removeDeprecatedAttrs from '../plugins/removeDeprecatedAttrs.js';
 import * as removeDesc from '../plugins/removeDesc.js';
 import * as removeDimensions from '../plugins/removeDimensions.js';
 import * as removeDoctype from '../plugins/removeDoctype.js';
@@ -79,6 +80,7 @@ export const builtin = [
   removeAttributesBySelector,
   removeAttrs,
   removeComments,
+  removeDeprecatedAttrs,
   removeDesc,
   removeDimensions,
   removeDoctype,
diff --git a/plugins/_collections.js b/plugins/_collections.js
index 832907103..fdae3558a 100644
--- a/plugins/_collections.js
+++ b/plugins/_collections.js
@@ -375,11 +375,35 @@ export const attrsGroupsDefaults = {
   },
 };
 
+/**
+ * @type {Record<string, { safe?: Set<string>, unsafe?: Set<string> }>}
+ * @see https://www.w3.org/TR/SVG11/intro.html#Definitions
+ */
+export const attrsGroupsDeprecated = {
+  animationAttributeTarget: { unsafe: new Set(['attributeType']) },
+  conditionalProcessing: { unsafe: new Set(['requiredFeatures']) },
+  core: { unsafe: new Set(['xml:base', 'xml:lang', 'xml:space']) },
+  presentation: {
+    unsafe: new Set([
+      'clip',
+      'color-profile',
+      'enable-background',
+      'glyph-orientation-horizontal',
+      'glyph-orientation-vertical',
+      'kerning',
+    ]),
+  },
+};
+
 /**
  * @type {Record<string, {
  *   attrsGroups: Set<string>,
  *   attrs?: Set<string>,
  *   defaults?: Record<string, string>,
+ *   deprecated?: {
+ *     safe?: Set<string>,
+ *     unsafe?: Set<string>,
+ *   },
  *   contentGroups?: Set<string>,
  *   content?: Set<string>,
  * }>}
@@ -574,6 +598,7 @@ export const elems = {
       name: 'sRGB',
       'rendering-intent': 'auto',
     },
+    deprecated: { unsafe: new Set(['name']) },
     contentGroups: new Set(['descriptive']),
   },
   cursor: {
@@ -958,6 +983,7 @@ export const elems = {
       width: '120%',
       height: '120%',
     },
+    deprecated: { unsafe: new Set(['filterRes']) },
     contentGroups: new Set(['descriptive', 'filterPrimitive']),
     content: new Set(['animate', 'set']),
   },
@@ -978,6 +1004,15 @@ export const elems = {
       'horiz-origin-x': '0',
       'horiz-origin-y': '0',
     },
+    deprecated: {
+      unsafe: new Set([
+        'horiz-origin-x',
+        'horiz-origin-y',
+        'vert-adv-y',
+        'vert-origin-x',
+        'vert-origin-y',
+      ]),
+    },
     contentGroups: new Set(['descriptive']),
     content: new Set(['font-face', 'glyph', 'hkern', 'missing-glyph', 'vkern']),
   },
@@ -1028,6 +1063,31 @@ export const elems = {
       'panose-1': '0 0 0 0 0 0 0 0 0 0',
       slope: '0',
     },
+    deprecated: {
+      unsafe: new Set([
+        'accent-height',
+        'alphabetic',
+        'ascent',
+        'bbox',
+        'cap-height',
+        'descent',
+        'hanging',
+        'ideographic',
+        'mathematical',
+        'panose-1',
+        'slope',
+        'stemh',
+        'stemv',
+        'unicode-range',
+        'units-per-em',
+        'v-alphabetic',
+        'v-hanging',
+        'v-ideographic',
+        'v-mathematical',
+        'widths',
+        'x-height',
+      ]),
+    },
     contentGroups: new Set(['descriptive']),
     content: new Set([
       // TODO: "at most one 'font-face-src' element"
@@ -1038,10 +1098,12 @@ export const elems = {
   'font-face-format': {
     attrsGroups: new Set(['core']),
     attrs: new Set(['string']),
+    deprecated: { unsafe: new Set(['string']) },
   },
   'font-face-name': {
     attrsGroups: new Set(['core']),
     attrs: new Set(['name']),
+    deprecated: { unsafe: new Set(['name']) },
   },
   'font-face-src': {
     attrsGroups: new Set(['core']),
@@ -1134,6 +1196,18 @@ export const elems = {
     defaults: {
       'arabic-form': 'initial',
     },
+    deprecated: {
+      unsafe: new Set([
+        'arabic-form',
+        'glyph-name',
+        'horiz-adv-x',
+        'orientation',
+        'unicode',
+        'vert-adv-y',
+        'vert-origin-x',
+        'vert-origin-y',
+      ]),
+    },
     contentGroups: new Set([
       'animation',
       'descriptive',
@@ -1173,6 +1247,14 @@ export const elems = {
       'vert-origin-x',
       'vert-origin-y',
     ]),
+    deprecated: {
+      unsafe: new Set([
+        'horiz-adv-x',
+        'vert-adv-y',
+        'vert-origin-x',
+        'vert-origin-y',
+      ]),
+    },
     contentGroups: new Set([
       'animation',
       'descriptive',
@@ -1236,6 +1318,7 @@ export const elems = {
   hkern: {
     attrsGroups: new Set(['core']),
     attrs: new Set(['u1', 'g1', 'u2', 'g2', 'k']),
+    deprecated: { unsafe: new Set(['g1', 'g2', 'k', 'u1', 'u2']) },
   },
   image: {
     attrsGroups: new Set([
@@ -1430,6 +1513,14 @@ export const elems = {
       'vert-origin-x',
       'vert-origin-y',
     ]),
+    deprecated: {
+      unsafe: new Set([
+        'horiz-adv-x',
+        'vert-adv-y',
+        'vert-origin-x',
+        'vert-origin-y',
+      ]),
+    },
     contentGroups: new Set([
       'animation',
       'descriptive',
@@ -1710,6 +1801,15 @@ export const elems = {
       contentScriptType: 'application/ecmascript',
       contentStyleType: 'text/css',
     },
+    deprecated: {
+      safe: new Set(['version']),
+      unsafe: new Set([
+        'baseProfile',
+        'contentScriptType',
+        'contentStyleType',
+        'zoomAndPan',
+      ]),
+    },
     contentGroups: new Set([
       'animation',
       'descriptive',
@@ -1956,11 +2056,13 @@ export const elems = {
       'viewTarget',
       'zoomAndPan',
     ]),
+    deprecated: { unsafe: new Set(['viewTarget', 'zoomAndPan']) },
     contentGroups: new Set(['descriptive']),
   },
   vkern: {
     attrsGroups: new Set(['core']),
     attrs: new Set(['u1', 'g1', 'u2', 'g2', 'k']),
+    deprecated: { unsafe: new Set(['g1', 'g2', 'k', 'u1', 'u2']) },
   },
 };
 
diff --git a/plugins/plugins-types.d.ts b/plugins/plugins-types.d.ts
index 6b06dcb00..246ea6249 100644
--- a/plugins/plugins-types.d.ts
+++ b/plugins/plugins-types.d.ts
@@ -144,6 +144,9 @@ type DefaultPlugins = {
   removeComments: {
     preservePatterns: Array<RegExp | string> | false;
   };
+  removeDeprecatedAttrs: {
+    removeUnsafe?: boolean;
+  };
   removeDesc: {
     removeAny?: boolean;
   };
diff --git a/plugins/preset-default.js b/plugins/preset-default.js
index a6742b13e..5291ab6c2 100644
--- a/plugins/preset-default.js
+++ b/plugins/preset-default.js
@@ -2,6 +2,7 @@ import { createPreset } from '../lib/svgo/plugins.js';
 import * as removeDoctype from './removeDoctype.js';
 import * as removeXMLProcInst from './removeXMLProcInst.js';
 import * as removeComments from './removeComments.js';
+import * as removeDeprecatedAttrs from './removeDeprecatedAttrs.js';
 import * as removeMetadata from './removeMetadata.js';
 import * as removeEditorsNSData from './removeEditorsNSData.js';
 import * as cleanupAttrs from './cleanupAttrs.js';
@@ -41,6 +42,7 @@ const presetDefault = createPreset({
     removeDoctype,
     removeXMLProcInst,
     removeComments,
+    removeDeprecatedAttrs,
     removeMetadata,
     removeEditorsNSData,
     cleanupAttrs,
diff --git a/plugins/removeDeprecatedAttrs.js b/plugins/removeDeprecatedAttrs.js
new file mode 100644
index 000000000..1894ca230
--- /dev/null
+++ b/plugins/removeDeprecatedAttrs.js
@@ -0,0 +1,120 @@
+import * as csswhat from 'css-what';
+import { attrsGroupsDeprecated, elems } from './_collections.js';
+import { collectStylesheet } from '../lib/style.js';
+
+export const name = 'removeDeprecatedAttrs';
+export const description = 'removes deprecated attributes';
+
+/**
+ * @typedef {{ safe?: Set<string>; unsafe?: Set<string> }} DeprecatedAttrs
+ * @typedef {import('../lib/types.js').XastElement} XastElement
+ */
+
+/**
+ * @param {import('../lib/types.js').Stylesheet} stylesheet
+ * @returns {Set<string>}
+ */
+function extractAttributesInStylesheet(stylesheet) {
+  const attributesInStylesheet = new Set();
+
+  stylesheet.rules.forEach((rule) => {
+    const selectors = csswhat.parse(rule.selector);
+    selectors.forEach((subselector) => {
+      subselector.forEach((segment) => {
+        if (segment.type !== 'attribute') {
+          return;
+        }
+
+        attributesInStylesheet.add(segment.name);
+      });
+    });
+  });
+
+  return attributesInStylesheet;
+}
+
+/**
+ * @param {XastElement} node
+ * @param {DeprecatedAttrs | undefined} deprecatedAttrs
+ * @param {import('./plugins-types.js').DefaultPlugins['removeDeprecatedAttrs']} params
+ * @param {Set<string>} attributesInStylesheet
+ */
+function processAttributes(
+  node,
+  deprecatedAttrs,
+  params,
+  attributesInStylesheet,
+) {
+  if (!deprecatedAttrs) {
+    return;
+  }
+
+  if (deprecatedAttrs.safe) {
+    deprecatedAttrs.safe.forEach((name) => {
+      if (attributesInStylesheet.has(name)) {
+        return;
+      }
+      delete node.attributes[name];
+    });
+  }
+
+  if (params.removeUnsafe && deprecatedAttrs.unsafe) {
+    deprecatedAttrs.unsafe.forEach((name) => {
+      if (attributesInStylesheet.has(name)) {
+        return;
+      }
+      delete node.attributes[name];
+    });
+  }
+}
+
+/**
+ * Remove deprecated attributes.
+ *
+ * @type {import('./plugins-types.js').Plugin<'removeDeprecatedAttrs'>}
+ */
+export function fn(root, params) {
+  const stylesheet = collectStylesheet(root);
+  const attributesInStylesheet = extractAttributesInStylesheet(stylesheet);
+
+  return {
+    element: {
+      enter: (node) => {
+        const elemConfig = elems[node.name];
+        if (!elemConfig) {
+          return;
+        }
+
+        // Special cases
+
+        // Removing deprecated xml:lang is safe when the lang attribute exists.
+        if (
+          elemConfig.attrsGroups.has('core') &&
+          node.attributes['xml:lang'] &&
+          !attributesInStylesheet.has('xml:lang') &&
+          node.attributes['lang']
+        ) {
+          delete node.attributes['xml:lang'];
+        }
+
+        // General cases
+
+        elemConfig.attrsGroups.forEach((attrsGroup) => {
+          processAttributes(
+            node,
+            attrsGroupsDeprecated[attrsGroup],
+            params,
+            attributesInStylesheet,
+          );
+        });
+
+        processAttributes(
+          node,
+          elemConfig.deprecated,
+          params,
+          attributesInStylesheet,
+        );
+      },
+    },
+  };
+}
diff --git a/test/plugins/_collections.test.js b/test/plugins/_collections.test.js
new file mode 100644
index 000000000..0dea420eb
--- /dev/null
+++ b/test/plugins/_collections.test.js
@@ -0,0 +1,24 @@
+import { elems } from '../../plugins/_collections.js';
+
+describe('elems.deprecated', () => {
+  Object.entries(elems).forEach(([tagName, elemConfig]) => {
+    const deprecated = elemConfig.deprecated;
+    if (!deprecated) {
+      return;
+    }
+
+    test(`${tagName} deprecated attributes are all known attributes`, () => {
+      if (deprecated.safe) {
+        deprecated.safe.forEach((attr) => {
+          expect(elemConfig.attrs).toContain(attr);
+        });
+      }
+
+      if (deprecated.unsafe) {
+        deprecated.unsafe.forEach((attr) => {
+          expect(elemConfig.attrs).toContain(attr);
+        });
+      }
+    });
+  });
+});
diff --git a/test/plugins/removeDeprecatedAttrs.01.svg.txt b/test/plugins/removeDeprecatedAttrs.01.svg.txt
new file mode 100644
index 000000000..d4bcf872d
--- /dev/null
+++ b/test/plugins/removeDeprecatedAttrs.01.svg.txt
@@ -0,0 +1,13 @@
+Removes safe deprecated version attribute from svg node.
+
+===
+
+<svg version="1.1" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <rect x="10" y="10" width="80" height="80"/>
+</svg>
+
+@@@
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <rect x="10" y="10" width="80" height="80"/>
+</svg>
diff --git a/test/plugins/removeDeprecatedAttrs.02.svg.txt b/test/plugins/removeDeprecatedAttrs.02.svg.txt
new file mode 100644
index 000000000..4a8b693ab
--- /dev/null
+++ b/test/plugins/removeDeprecatedAttrs.02.svg.txt
@@ -0,0 +1,13 @@
+Does not remove unsafe deprecated viewTarget attribute from view node by default.
+
+===
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <view id="one" viewBox="0 0 100 100" viewTarget=""/>
+</svg>
+
+@@@
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <view id="one" viewBox="0 0 100 100" viewTarget=""/>
+</svg>
diff --git a/test/plugins/removeDeprecatedAttrs.03.svg.txt b/test/plugins/removeDeprecatedAttrs.03.svg.txt
new file mode 100644
index 000000000..af835184f
--- /dev/null
+++ b/test/plugins/removeDeprecatedAttrs.03.svg.txt
@@ -0,0 +1,17 @@
+Remove unsafe deprecated viewTarget attribute from view node with param.
+
+===
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <view id="one" viewBox="0 0 100 100" viewTarget=""/>
+</svg>
+
+@@@
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <view id="one" viewBox="0 0 100 100"/>
+</svg>
+
+@@@
+
+{ "removeUnsafe": true }
diff --git a/test/plugins/removeDeprecatedAttrs.04.svg.txt b/test/plugins/removeDeprecatedAttrs.04.svg.txt
new file mode 100644
index 000000000..37158db23
--- /dev/null
+++ b/test/plugins/removeDeprecatedAttrs.04.svg.txt
@@ -0,0 +1,27 @@
+Removes deprecated presentation group attribute enable-background.
+
+===
+
+<svg xmlns="http://www.w3.org/2000/svg" width="100.5" height=".5" enable-background="new 0 0 100.5 .5">
+    <defs>
+        <filter id="ShiftBGAndBlur">
+            <feOffset dx="0" dy="75"/>
+        </filter>
+    </defs>
+    test
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" width="100.5" height=".5">
+    <defs>
+        <filter id="ShiftBGAndBlur">
+            <feOffset dx="0" dy="75"/>
+        </filter>
+    </defs>
+    test
+</svg>
+
+@@@
+
+{ "removeUnsafe": true }
diff --git a/test/plugins/removeDeprecatedAttrs.05.svg.txt b/test/plugins/removeDeprecatedAttrs.05.svg.txt
new file mode 100644
index 000000000..ff762fde9
--- /dev/null
+++ b/test/plugins/removeDeprecatedAttrs.05.svg.txt
@@ -0,0 +1,13 @@
+Removes deprecated xml:lang attribute when lang attribute exists.
+
+===
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <text xml:lang="en-CA" lang="en-US">English text</text>
+</svg>
+
+@@@
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <text lang="en-US">English text</text>
+</svg>
diff --git a/test/plugins/removeDeprecatedAttrs.06.svg.txt b/test/plugins/removeDeprecatedAttrs.06.svg.txt
new file mode 100644
index 000000000..86dcb2768
--- /dev/null
+++ b/test/plugins/removeDeprecatedAttrs.06.svg.txt
@@ -0,0 +1,13 @@
+Keeps xml:lang attribute when lang attribute doesn't exist.
+
+===
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <text xml:lang="en-US">English text</text>
+</svg>
+
+@@@
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <text xml:lang="en-US">English text</text>
+</svg>
diff --git a/test/plugins/removeDeprecatedAttrs.07.svg.txt b/test/plugins/removeDeprecatedAttrs.07.svg.txt
new file mode 100644
index 000000000..685f98eef
--- /dev/null
+++ b/test/plugins/removeDeprecatedAttrs.07.svg.txt
@@ -0,0 +1,17 @@
+Removes unsafe xml:lang attribute when lang attribute doesn't exist with removeUnsafe param.
+
+===
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <text xml:lang="en-US">English text</text>
+</svg>
+
+@@@
+
+<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <text>English text</text>
+</svg>
+
+@@@
+
+{ "removeUnsafe": true }
diff --git a/test/plugins/removeDeprecatedAttrs.08.svg.txt b/test/plugins/removeDeprecatedAttrs.08.svg.txt
new file mode 100644
index 000000000..5b5499f4e
--- /dev/null
+++ b/test/plugins/removeDeprecatedAttrs.08.svg.txt
@@ -0,0 +1,23 @@
+Keeps deprecated version attribute when it is a CSS selectors
+
+===
+
+<svg version="1.1" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <style>
+        <![CDATA[svg[version="1.1"]{fill:blue;}rect[clip]{fill:green;}]]>
+    </style>
+    <rect x="10" y="10" width="80" height="80" clip="1"/>
+</svg>
+
+@@@
+
+<svg version="1.1" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+    <style>
+        <![CDATA[svg[version="1.1"]{fill:blue;}rect[clip]{fill:green;}]]>
+    </style>
+    <rect x="10" y="10" width="80" height="80" clip="1"/>
+</svg>
+
+@@@
+
+{ "removeUnsafe": true }