Switch from Esprima to Espree for JavaScript linting in CodeMirror. #10806

westonruter · 2026-01-27T21:49:16Z

Previously developed in westonruter#4 as a sub-PR off of #10778

Depends on:

Allow classic scripts to depend on modules #8024

New Linter Integration:
- Introduces src/js/_enqueues/vendor/codemirror/javascript-lint.js which uses espree (v9.6.1) for parsing and error reporting.
- This replaces the previous dependency on the jshint and esprima scripts. The espree module is now loaded via a dynamic import on demand by the new javascript lint integration.
- This custom linter is bundled into the CodeMirror build via tools/vendors/codemirror-entry.js.
Script Modules:
- Registers espree as a script module in src/wp-includes/script-modules.php.
- Adds a workaround in the wp-codemirror registration to ensure espree is included in the importmap.
Editor Settings:
- Updates wp_get_code_editor_settings() in src/wp-includes/general-template.php to use ES11 defaults.
- Synchronizes JSHint settings from .jshintrc, even though these are not supported by Espree.
Deprecations:
- Marks esprima and jshint script handles as deprecated in src/wp-includes/script-loader.php.
Build Tools:
- Updates Webpack configuration (tools/webpack/codemirror.config.js) to bundle espree as a module.
- Updates codemirror-entry.js to use the new local javascript-lint.js.

Trac ticket: https://core.trac.wordpress.org/ticket/64558

This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

github-actions · 2026-01-27T21:55:21Z

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Replaces the `esprima`-based validation in the code editor with `espree` to provide support for modern JavaScript (ES6+). Key Changes: 1. **New Linter Integration:** * Introduces `src/js/_enqueues/vendor/codemirror/javascript-lint.js` which uses `espree` (v9.6.1) for parsing and error reporting. * This replaces the previous dependency on the `jshint` and `esprima` scripts. The `espree` module is now loaded via a dynamic import on demand by the new javascript lint integration. * This custom linter is bundled into the CodeMirror build via `tools/vendors/codemirror-entry.js`. 2. **Script Modules:** * Registers `espree` as a script module in `src/wp-includes/script-modules.php`. * Adds a workaround in the `wp-codemirror` registration to ensure `espree` is included in the importmap. 3. **Editor Settings:** * Updates `wp_get_code_editor_settings()` in `src/wp-includes/general-template.php` to use ES11 defaults. * Synchronizes JSHint settings from .jshintrc, even though these are not supported by Espree. 4. **Deprecations:** * Marks `esprima` and `jshint` script handles as deprecated in `src/wp-includes/script-loader.php`. 5. **Build Tools:** * Updates Webpack configuration (`tools/webpack/codemirror.config.js`) to bundle `espree` as a module. * Updates `codemirror-entry.js` to use the new local `javascript-lint.js`. Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

…into replace-esprima-with-espree

… at 9acd7f0 Co-authored-by: Jon Surrell <jonsurrell@git.wordpress.org> Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

…resolution. By adding /* webpackIgnore: true */ to the dynamic import in javascript-lint.js, we prevent Webpack from bundling Espree into a separate chunk. This allows the browser to resolve Espree at runtime using the Import Map. Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

The IIFE in javascript-lint.js is removed as it is redundant when bundled by Webpack. Both javascript-lint.js and codemirror-entry.js are updated to use 'const' instead of 'var' for the CodeMirror require, aligning with modern JavaScript practices in the project. Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

…vascript-lint.js. Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

sirreal · 2026-02-03T13:20:14Z

src/js/_enqueues/vendor/codemirror/javascript-lint.js

+ * @since 7.0.0
+ */
+
+const CodeMirror = require( 'codemirror' );


This all requires webpack processing. Can we use a static import here which is more common in modern, compiled JavaScript?

Webpack processing is required anyway since it creates the bundle from codemirror-entry.js. Or is this for the future where we could possibly re-use this module as-is with v6?

In any case, I've switched to using ESM instead of CommonJS for everything in 9e3038d.

… at 9acd7f0...3a67800 Co-authored-by: Jon Surrell <jonsurrell@git.wordpress.org> Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

…into replace-esprima-with-espree

github-actions · 2026-02-04T01:47:48Z

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props westonruter, jonsurrell.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

Update src/js/_enqueues/vendor/codemirror/javascript-lint.js and tools/vendors/codemirror-entry.js to use ESM import statements instead of CommonJS require(). This aligns with modern JavaScript standards and ensures compatibility with the project's build process. Co-authored-by: Jon Surrell <jonsurrell@git.wordpress.org> Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

westonruter · 2026-02-04T01:58:54Z

tools/vendors/espree-entry.js

@@ -0,0 +1 @@
+export * from 'espree';


Unfortunately, Epsree does not have an ES module included in its distribution.

Copilot

Pull request overview

This PR replaces Esprima/JSHint with Espree for JavaScript linting in CodeMirror to address GPL compatibility issues. The change introduces a new custom JavaScript linter that uses the Espree parser (v9.6.1) for syntax validation, registers Espree as a script module, and deprecates the legacy esprima and jshint script handles.

Changes:

Introduces a custom JavaScript linter using Espree for syntax-only validation (no linting rules)
Registers Espree as a script module with import map integration via module dependencies
Updates build tooling to generate separate espree.min.js module and integrate the new linter into codemirror.min.js

Reviewed changes

Copilot reviewed 9 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/js/_enqueues/vendor/codemirror/javascript-lint.js	New custom JavaScript linter using Espree for syntax validation
tools/webpack/codemirror.config.js	Adds espree build configuration and restructures codemirror build
tools/vendors/espree-entry.js	Entry point for bundling espree as a module
tools/vendors/codemirror-entry.js	Updates to use new javascript-lint and ES module imports
src/wp-includes/script-modules.php	Registers espree as a script module
src/wp-includes/script-loader.php	Adds module dependency for wp-codemirror and deprecates jshint/esprima
src/wp-includes/general-template.php	Updates JSHint settings to ES11 and adds clarifying comments
tests/phpunit/tests/dependencies/scripts.php	Updates tests to reflect jshint key changes and adds espree to exclusions
tests/phpunit/tests/widgets/wpWidgetCustomHtml.php	Removes jshint enqueue test expectation
package.json	Adds espree 9.6.1 and @types/codemirror dependencies
package-lock.json	Lock file updates for new dependencies

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Copilot · 2026-02-04T02:06:19Z

src/wp-includes/script-loader.php

 	);

 	$scripts->add( 'wp-codemirror', '/wp-includes/js/codemirror/codemirror.min.js', array(), '5.65.20' );
+	did_action( 'init' ) && $scripts->add_data( 'wp-codemirror', 'module_dependencies', array( 'espree' ) );


The condition did_action( 'init' ) is used here as a guard, but this creates a timing-dependent behavior. If this code runs before the 'init' action, the module dependency won't be added. Consider either: (1) always adding this data unconditionally, or (2) hooking into the 'init' action to add this dependency at the appropriate time. The current pattern may lead to inconsistent behavior depending on when wp_default_scripts is called.

Suggested change

did_action( 'init' ) && $scripts->add_data( 'wp-codemirror', 'module_dependencies', array( 'espree' ) );

$scripts->add_data( 'wp-codemirror', 'module_dependencies', array( 'espree' ) );

Copilot · 2026-02-04T02:06:19Z

src/wp-includes/general-template.php

+			// The following are copied from <https://github.com/WordPress/wordpress-develop/blob/6.9.0/.jshintrc>.
+			// Nevertheless, they are not supported by Espree, which is used instead of JSHint for licensing reasons.


The comment states that the JSHint options are "not supported by Espree", but this is only partially accurate. While most of the JSHint options listed (boss, curly, eqeqeq, etc.) are indeed linting rules that Espree doesn't support, the options esversion, es5, es3, module, and strict ARE used by the Espree integration in javascript-lint.js. The comment should be clarified to distinguish between the parsing-related options that Espree does support and the linting-rule options that it doesn't support. This would help future developers understand which options are still relevant.

Suggested change

// The following are copied from <https://github.com/WordPress/wordpress-develop/blob/6.9.0/.jshintrc>.

// Nevertheless, they are not supported by Espree, which is used instead of JSHint for licensing reasons.

// The following JSHint *linting rule* options are copied from

// <https://github.com/WordPress/wordpress-develop/blob/6.9.0/.jshintrc>.

// Parsing-related options such as `esversion` (and, in other contexts, `es5`, `es3`, `module`, `strict`)

// are honored by the Espree-based integration, but these linting-rule options are not interpreted by Espree

// and are kept only for compatibility/documentation with the original JSHint configuration.

westonruter force-pushed the replace-esprima-with-espree branch from 5c7da3d to cfd3baf Compare January 27, 2026 22:06

westonruter mentioned this pull request Jan 28, 2026

CodeMirror: Esprima to Espree for JavaScript validation westonruter/wordpress-develop#4

Closed

westonruter and others added 2 commits January 28, 2026 10:11

Simplify javascript-lint module definition and ensure proper types

bd2376c

westonruter force-pushed the replace-esprima-with-espree branch from cfd3baf to bd2376c Compare January 28, 2026 18:39

westonruter and others added 6 commits January 30, 2026 19:53

Merge branch 'trunk' of https://github.com/WordPress/wordpress-develop …

9d5d79a

…into replace-esprima-with-espree

Squash sirreal:scripts/allow-script-module-dependency (WordPress#8024)…

daa5e2e

… at 9acd7f0 Co-authored-by: Jon Surrell <jonsurrell@git.wordpress.org> Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Leverage the module_dependencies arg to add espree to importmap

34f5e4c

Fix minification of espree after debugging

57cd3b0

westonruter force-pushed the replace-esprima-with-espree branch from 942ce9e to 99a6994 Compare January 31, 2026 04:44

westonruter mentioned this pull request Jan 31, 2026

Allow classic scripts to depend on modules #8024

Closed

westonruter and others added 2 commits January 30, 2026 20:54

CodeMirror: Add since 7.0.0 JSDoc tags to javascript-lint.js.

0f8878d

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Change method for suppressing JSHint warning for console.warn() in ja…

89c8db8

…vascript-lint.js. Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

westonruter mentioned this pull request Feb 1, 2026

Upgrade CodeMirror to latest v5 #10778

Closed

sirreal self-requested a review February 3, 2026 13:15

sirreal reviewed Feb 3, 2026

View reviewed changes

westonruter and others added 2 commits February 3, 2026 17:45

Squash sirreal:scripts/allow-script-module-dependency (WordPress#8024)…

0edaefa

… at 9acd7f0...3a67800 Co-authored-by: Jon Surrell <jonsurrell@git.wordpress.org> Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Merge branch 'trunk' of https://github.com/WordPress/wordpress-develop …

7a8d756

…into replace-esprima-with-espree

westonruter marked this pull request as ready for review February 4, 2026 01:47

westonruter commented Feb 4, 2026

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Switch from Esprima to Espree for JavaScript linting in CodeMirror. #10806

Switch from Esprima to Espree for JavaScript linting in CodeMirror. #10806

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westonruter commented Jan 27, 2026 •

edited

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	did_action( 'init' ) && $scripts->add_data( 'wp-codemirror', 'module_dependencies', array( 'espree' ) );
	$scripts->add_data( 'wp-codemirror', 'module_dependencies', array( 'espree' ) );

		// The following are copied from <https://github.com/WordPress/wordpress-develop/blob/6.9.0/.jshintrc>.
		// Nevertheless, they are not supported by Espree, which is used instead of JSHint for licensing reasons.

-			// The following are copied from <https://github.com/WordPress/wordpress-develop/blob/6.9.0/.jshintrc>.
-			// Nevertheless, they are not supported by Espree, which is used instead of JSHint for licensing reasons.
+			// The following JSHint *linting rule* options are copied from
+			// <https://github.com/WordPress/wordpress-develop/blob/6.9.0/.jshintrc>.
+			// Parsing-related options such as `esversion` (and, in other contexts, `es5`, `es3`, `module`, `strict`)
+			// are honored by the Espree-based integration, but these linting-rule options are not interpreted by Espree
+			// and are kept only for compatibility/documentation with the original JSHint configuration.

Switch from Esprima to Espree for JavaScript linting in CodeMirror. #10806

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Test using WordPress Playground

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westonruter commented Jan 27, 2026 •

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