Build: Skip sourcemaps for WASM-inlined script module workers by adamsilverstein · Pull Request #75993 · WordPress/gutenberg

adamsilverstein · 2026-02-27T04:46:22Z

Summary

Suppresses source map generation for WASM-inlined worker builds (currently only @wordpress/vips/worker). The worker is ~13MB of base64-encoded WASM data where source maps provide no debugging value, yet the .map file is nearly the same size (~13MB).

This builds on #76615 (skip unminified worker build) and #76639 (remove unused JXL WASM) which already landed on trunk.

Size impact

	Trunk	This PR	Saved
`build/modules/vips/`	26 MB	10 MB	16 MB
Plugin ZIP	33 MB	27 MB	~6 MB (18%)

What changed

The only functional change is setting sourcemap: ! isWasmWorker in the esbuild config for script module builds. This skips generating worker.min.js.map (~13MB) and the unminified loader's .map files for packages whose exports correspond to wpWorkers entries.

Files removed from `build/modules/vips/`

File	Size	Status
`worker.min.js.map`	13.2 MB	Removed by this PR
`loader.js.map`	999 B	Removed by this PR
`loader.min.js.map`	1,006 B	Removed by this PR
`loader.js` (unminified)	173 B	Removed by this PR
`worker.js` (unminified)	~13 MB	Already removed by #76615
`vips-jxl.wasm` (inlined)	~3 MB	Already removed by #76639

Context

Fixes #64734

Test plan

npm run build — verify build/modules/vips/ contains only worker.min.js, loader.min.js, and *.asset.php (no .map files)
Verify other script modules still have source maps (e.g. ls build/modules/interactivity/)
Upload an image in the editor — verify VIPS processing works correctly

github-actions · 2026-02-27T04:46:31Z

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.

If you're merging code through a pull request on GitHub, copy and paste the following into the bottom of the merge commit message.

Co-authored-by: adamsilverstein <adamsilverstein@git.wordpress.org>
Co-authored-by: andrewserong <andrewserong@git.wordpress.org>
Co-authored-by: youknowriad <youknowriad@git.wordpress.org>
Co-authored-by: Mamaduka <mamaduka@git.wordpress.org>
Co-authored-by: desrosj <desrosj@git.wordpress.org>

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Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Mamaduka · 2026-03-02T06:16:51Z

@adamsilverstein, have you tested with SCRIPT_DEBUG enabled? The plugin and core will use non-minified files when script debugging is enabled. If the file doesn't exist, this could potentially break things. At least it will produce a 404 error.

We might have to add special handling for this file. Here's a related discussion - #75396.

andrewserong · 2026-03-02T06:26:53Z

We might have to add special handling for this file. Here's a related discussion - #75396.

Thanks for flagging — that's interesting, that case is about an environment-based flag (i.e. running a production build), whereas this case is about the package itself having an opinion on how it's built. I wonder if there's a way to combine these concepts / features into a single idea. Or failing that, closely related ones 🤔

adamsilverstein · 2026-03-02T06:45:43Z

@adamsilverstein , have you tested with SCRIPT_DEBUG enabled? The plugin and core will use non-minified files when script debugging is enabled. If the file doesn't exist, this could potentially break things. At least it will produce a 404 error.

We might have to add special handling for this file. Here's a related discussion - #75396.

That makes sense. My local is loading the core version now on trunk, so I need to test against 6.9.

adamsilverstein · 2026-03-02T07:02:02Z

I verified this is causing an issue with 6.9, working on it.

Mamaduka · 2026-03-02T07:03:55Z

Thanks for the confirmation, @adamsilverstein! I think we'll have the same issue with 7.0 once changes are synced.

youknowriad · 2026-03-02T09:33:44Z

What's the reasoning for wanting to skip these files. What is special for these packages compared to all the other ones?

adamsilverstein · 2026-03-02T10:05:12Z

What's the reasoning for wanting to skip these files. What is special for these packages compared to all the other ones?

Their very large size. This fixes https://core.trac.wordpress.org/ticket/64734 see that ticket for details.

@youknowriad - If preferable we can ship these files with Gutenberg, but omit them during the WordPress build process. what do you think?

youknowriad · 2026-03-02T10:09:40Z

@youknowriad - If preferable we can ship these files with Gutenberg, but omit them during the WordPress build process. what do you think?

I'm not sure, I see Gutenberg as alpha, so I believe we should do the same.

It seems like the "wasm" package is a good enough differentiation to consider it special.

--

Should we name the flag wpScriptDebugSupport: true/false and support it for all the outputs of a given package (styles, scripts or script modules)

adamsilverstein · 2026-03-02T10:37:57Z

Should we name the flag wpScriptDebugSupport: true/false and support it for all the outputs of a given package (styles, scripts or script modules)

that makes sense, and i assume the default is true since we normally do support debugging by outputting map files and unminified versions.

adamsilverstein · 2026-03-02T12:12:31Z

I started working on a simpler solution for core since we probably need to adjust loading there as well to always use the minified VIPS file: WordPress/wordpress-develop#11109

The previous commit added wpScriptModuleMinifiedOnly to package.json but didn't pass the flag through to the PHP registry data. Without the minified_only entry in the registry, the PHP template couldn't override the .js extension when SCRIPT_DEBUG is on, causing module resolution failures for packages that only ship .min.js files.

github-actions · 2026-03-02T13:07:17Z

Flaky tests detected in 43735c6.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/23452985817
📝 Reported issues:

[Flaky Test] post title and content are editable and blocks can be inserted #76524 in /test/e2e/specs/editor/various/post-content-focus-mode.spec.js

Broadens the flag to cover all build outputs (scripts, script modules, and styles) instead of just script modules. When set to false, skips unminified builds and sourcemaps for all output types. Adds file_exists fallbacks in script and style PHP templates so SCRIPT_DEBUG gracefully falls back to minified files when unminified versions don't exist.

The file_exists fallback in the PHP template handles missing unminified files generically, making the per-module minified_only flag in the registry unnecessary.

- Collapse multiline `skipDebugBuilds` assignments to single lines (prettier) - Re-align JSDoc @typedef/@Property columns in package-utils.mjs Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

youknowriad · 2026-03-04T10:40:10Z

This is looking good for me.

desrosj · 2026-03-20T18:25:41Z

@adamsilverstein is this still needed after the recent work to shrink the related source?

adamsilverstein · 2026-03-21T19:45:06Z

Maybe not? We might still want it to reduce Gutenberg's package size.

adamsilverstein · 2026-03-23T17:45:02Z

@adamsilverstein is this still needed after the recent work to shrink the related source?

we do still want this PR:

Plugin ZIP Size

	Size
Trunk (current)	33 MB (34,154,414 bytes)
PR #75993	27 MB (27,890,699 bytes)
Savings	~6 MB (18%)

Build Directory

	Trunk	PR	Saved
`build/` total	132 MB	113 MB	19 MB
`build/modules/vips/`	26 MB	10 MB	16 MB
`.map` files in `build/modules/`	19.2 MB	5.8 MB	13.4 MB

What the PR still removes vs current trunk

The recent PRs (#76615, #76639, #76657) already landed the unminified worker skip, JXL WASM removal, and SCRIPT_DEBUG fallback. What this PR still does on top of trunk:

File removed	Size
`vips/worker.min.js.map`	13.2 MB
`vips/loader.js` (unminified)	173 B
`vips/loader.js.map`	999 B
`vips/loader.min.js.map`	1,006 B
Total additional savings	~13.2 MB from build, ~6 MB from ZIP

The remaining value of this PR is removing source maps from the vips build output, which saves ~13 MB from the build directory and ~6 MB from the plugin ZIP. The non-vips source maps (5.8 MB) are still present in both builds.

Resolve conflicts with #76615 and #76657 which landed the unminified worker skip and SCRIPT_DEBUG fallback. Keep trunk's isWasmWorker/min_only approach and add sourcemap suppression for WASM workers. Remove the unused wpScriptDebugSupport flag and related dead code paths. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

adamsilverstein · 2026-04-21T19:00:38Z

@youknowriad can you please approve this if it looks good to you?

adamsilverstein · 2026-04-24T15:40:22Z

This worked well in my local testing.

adamsilverstein requested review from ajitbohra, nerrad and ntwb as code owners February 27, 2026 04:46

adamsilverstein added [Status] In Progress Tracking issues with work in progress [Type] Build Tooling Issues or PRs related to build tooling [Feature] Client Side Media Media processing in the browser with WASM labels Feb 27, 2026

adamsilverstein added this to WordPress 7.0 Editor Tasks Feb 27, 2026

adamsilverstein self-assigned this Feb 27, 2026

github-project-automation Bot moved this to 🔎 Needs Review in WordPress 7.0 Editor Tasks Feb 27, 2026

adamsilverstein requested review from a team, DAreRodz, desrosj, ellatrix, fabiankaegy, gigitux, juanmaguitar, luisherranz, ntsekouras, oandregal and spacedmonkey as code owners February 27, 2026 05:16

Fix JSDoc line alignment in package-utils.mjs

f01cb58

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

adamsilverstein and others added 3 commits March 3, 2026 11:11

Remove minifiedOnly from module registry data

938d47c

The file_exists fallback in the PHP template handles missing unminified files generically, making the per-module minified_only flag in the registry unnecessary.

Fix prettier and JSDoc lint errors in wp-build

de8559a

- Collapse multiline `skipDebugBuilds` assignments to single lines (prettier) - Re-align JSDoc @typedef/@Property columns in package-utils.mjs Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

adamsilverstein mentioned this pull request Mar 23, 2026

Client Side Media iteration for WordPress 7.1 #76756

Open

adamsilverstein and others added 4 commits March 23, 2026 10:54

Revert unrelated whitespace change in package-utils.mjs

339d5f5

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Remove unrelated comment and formatting changes from merge

501d1f9

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Remove hardcoded size from comment

43735c6

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

adamsilverstein mentioned this pull request Apr 1, 2026

Add JPEG XL (JXL) support #76981

Open

7 tasks

youknowriad approved these changes Apr 21, 2026

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github-actions Bot mentioned this pull request Apr 28, 2026

Add a scheduled Gutenberg upstream TypeScript watch and triage workflow imjlk/wp-typia#283

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Summary

Size impact

What changed

Files removed from build/modules/vips/

Context

Test plan

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Mamaduka commented Mar 2, 2026

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andrewserong commented Mar 2, 2026

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youknowriad commented Mar 4, 2026

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adamsilverstein commented Mar 23, 2026

Plugin ZIP Size

Build Directory

What the PR still removes vs current trunk

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adamsilverstein commented Feb 27, 2026 •

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Files removed from `build/modules/vips/`

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