Editor Styles: Add a transform for button rules

packages/block-editor/src/utils/transform-styles/index.js

@@ -14,6 +14,7 @@ import { compose } from '@wordpress/compose';
 import traverse from './traverse';
 import urlRewrite from './transforms/url-rewrite';
 import wrap from './transforms/wrap';
+import avoidEditorComponents from './transforms/avoid-editor-components';
 
 /**
  * Applies a series of CSS rule transforms to wrap selectors inside a given class and/or rewrite URLs depending on the parameters passed.
@@ -29,6 +30,7 @@ const transformStyles = ( styles, wrapperClassName = '' ) => {
 			const transforms = [];
 			if ( wrapperClassName && ! __experimentalNoWrapper ) {
 				transforms.push( wrap( wrapperClassName ) );
+				transforms.push( avoidEditorComponents() );
 			}
 			if ( baseURL ) {
 				transforms.push( urlRewrite( baseURL ) );

packages/block-editor/src/utils/transform-styles/transforms/avoid-editor-components.js

@@ -0,0 +1,46 @@
+/**
+ * This transform targets inputs and buttons and prevents css styles for the editor
+ * from the theme to bleed into the editor's components. It is a bit hacky but
+ * it is contained and prevents us from having to do make changes over multiple files.
+ *
+ * @constant string IS_BUTTON_TAG Regex to check if the selector is a button tag selector.
+ * @constant string IS_INPUT_TAG Regex to check if the selector is an input tag selector.
+ */
+const IS_BUTTON_TAG = /^(button).*$/;
+
+const IS_INPUT_TAG = /^(input).*$/;
+
+const avoidEditorComponents = ( ignore = [] ) => ( node ) => {
+	const updateSelector = ( selector ) => {
+		if ( ignore.includes( selector.trim() ) ) {
+			return selector;
+		}
+
+		if ( selector.match( IS_BUTTON_TAG ) ) {
+			return selector.replace(
+				IS_BUTTON_TAG,
+				'button:not(.components-button):not([id^=mceu_])'
+			);
+		}
+
+		if ( selector.match( IS_INPUT_TAG ) ) {
+			return selector.replace(
+				IS_INPUT_TAG,
+				'input:not(.components-text-control__input):not(.components-placeholder__input):not(.components-form-token-field__input)'
+			);
+		}
+
+		return selector;
+	};
+
+	if ( node.type === 'rule' ) {
+		return {
+			...node,
+			selectors: node.selectors.map( updateSelector ),
+		};
+	}
+
+	return node;
+};
+
+export default avoidEditorComponents;

packages/block-editor/src/utils/transform-styles/transforms/test/__snapshots__/avoid-editor-components.js.snap

@@ -0,0 +1,13 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`CSS selector wrap should add editor classes to buttons 1`] = `
+"button:not(.components-button):not([id^=mceu_]) {
+background-color: #ff0000;
+}"
+`;
+
+exports[`CSS selector wrap should add editor classes to inputs 1`] = `
+"input:not(.components-text-control__input):not(.components-placeholder__input):not(.components-form-token-field__input) {
+border-color: #ff0000;
+}"
+`;

packages/block-editor/src/utils/transform-styles/transforms/test/__snapshots__/wrap.js.snap

@@ -22,6 +22,12 @@ color: red;
 }"
 `;
 
+exports[`CSS selector wrap should replace :root selectors 1`] = `
+".my-namespace {
+--my-color: #ff0000;
+}"
+`;
+
 exports[`CSS selector wrap should replace root tags 1`] = `
 ".my-namespace,
 .my-namespace h1 {
@@ -41,9 +47,3 @@ exports[`CSS selector wrap should wrap regular selectors 1`] = `
 color: red;
 }"
 `;
-
-exports[`CSS selector wrap should replace :root selectors 1`] = `
-".my-namespace {
---my-color: #ff0000;
-}"
-`;

packages/block-editor/src/utils/transform-styles/transforms/test/avoid-editor-components.js

@@ -0,0 +1,29 @@
+/**
+ * Internal dependencies
+ */
+import traverse from '../../traverse';
+import avoidEditorComponents from '../avoid-editor-components';
+
+describe( 'CSS selector wrap', () => {
+	it( 'should add editor classes to buttons', () => {
+		const callback = avoidEditorComponents();
+		const input = `
+		button {
+			background-color: #ff0000;
+		}`;
+		const output = traverse( input, callback );
+
+		expect( output ).toMatchSnapshot();
+	} );
+
+	it( 'should add editor classes to inputs', () => {
+		const callback = avoidEditorComponents();
+		const input = `
+		input {
+			border-color: #ff0000;
+		}`;
+		const output = traverse( input, callback );
+
+		expect( output ).toMatchSnapshot();
+	} );
+} );