fix: preserve CSS propagation for partial pages imported as components by 0xbejaxer · Pull Request #16415 · withastro/astro

0xbejaxer · 2026-04-20T18:49:13Z

Summary

refine build CSS boundary detection so top-level pages only stop traversal when they are referenced exclusively by Astro's virtual page module
allow partial pages (export const partial = true) that are imported by other pages to keep propagating transitive component CSS in production builds
add a regression fixture and build test that verifies transitive CSS from an imported partial is present in index.html output

Validation

pnpm -C packages/astro exec astro-scripts test "test/partials-css-boundary.test.ts"
Full PR CI matrix is green (build, lint, test, E2E, platform matrix)

Fixes #16296.

changeset-bot · 2026-04-20T18:49:22Z

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Latest commit: f22ad01

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Treat top-level pages as CSS boundaries only when they are referenced exclusively by the virtual page module, so partial pages imported as components continue propagating transitive styles in production builds. Made-with: Cursor

codspeed-hq · 2026-04-20T19:29:31Z

Merging this PR will not alter performance

✅ 18 untouched benchmarks

_{Comparing 0xbejaxer:fix-16296-partial-css-boundary (f22ad01) with main (471a4d6)¹}

No successful run was found on main (1f31d6f) during the generation of this report, so 471a4d6 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

Correct the regression fixture path so the partial page can resolve ResultsTable during build on CI. Made-with: Cursor

Assert that scoped ResultsTable selectors are present in extracted styles instead of matching a specific color token that can be minified differently across environments. Made-with: Cursor

0xbejaxer · 2026-04-20T21:54:09Z

Quick update after addressing CI feedback:

Fixed fixture import path in the new regression setup
Made the assertion minification-safe (checks for scoped selector presence instead of a specific color literal)
Kept the core fix unchanged: treat top-level pages as CSS boundaries only when they are imported exclusively by the virtual page module, so imported partial pages continue propagating transitive CSS

All checks are now passing on this branch. Happy to adjust test coverage/assertions further if maintainers prefer a different shape.

AceCodePt · 2026-04-21T05:18:34Z

Thanks @0xbejaxer !
This is a big help!

Trigger a fresh workflow run for PR withastro#16415 after unrelated flaky E2E failures in actions-blog/cloudflare/hmr tests. Made-with: Cursor

leefreemanxyz · 2026-04-29T09:22:38Z

Thanks for opening this PR @0xbejaxer, I hope it can get some attention soon and merged 🙏

@Fryuni

* Fix merge-fix workflow to handle conflict markers before install (#16539) * Handle merge conflicts in merge-fix workflow by stripping JSON/YAML markers and verifying via AI (#16541) * [ci] format * fix(render): avoid script dedup state consumption in inert template c… (#16527) * fix(render): avoid script dedup state consumption in inert template contexts #16525 * fix(render): normalize inert script dedup test outputs to strings * fix: add missing hydration metadata fields in inert-script-dedup tests * test(app): add component-level inert template script dedup coverage * test(app): stabilize inert script dedup regression coverage * fix(astro): move inert template dedup logic into hydration/directive script guards * [ci] format * fix: emit fallback rewrite pages (#16515) * fix(i18n): emit fallback rewrite pages * chore: add changeset * [ci] format * refactor(astro): replace tsconfck with get-tsconfig (#16433) * fix(language-server): remove circular dependency on svelte/vue integrations (#16532) * [ci] format * fix(upgrade): use bundled JS output (#16547) * Update dependency postcss to v8.5.10 [SECURITY] (#16489) Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com> * Update dependency fastify to v5.8.5 [SECURITY] (#16346) Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com> * Update dependency fast-xml-parser to v5.7.0 [SECURITY] (#16452) Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com> * fix(cloudflare): preserve existing KV namespace bindings when injecting SESSION (#16555) * fix(slots): unwrap conditional slot callbacks (#16509) Co-authored-by: cyphercodes <cyphercodes@users.noreply.github.com> * fix: preserve CSS propagation for partial pages imported as components (#16415) * fix(astro): preserve CSS from imported partial pages Treat top-level pages as CSS boundaries only when they are referenced exclusively by the virtual page module, so partial pages imported as components continue propagating transitive styles in production builds. Made-with: Cursor * test(astro): fix partial CSS fixture component import path Correct the regression fixture path so the partial page can resolve ResultsTable during build on CI. Made-with: Cursor * test(astro): make partial css assertion robust to minification Assert that scoped ResultsTable selectors are present in extracted styles instead of matching a specific color token that can be minified differently across environments. Made-with: Cursor * chore: rerun CI after unrelated e2e flake Trigger a fresh workflow run for PR #16415 after unrelated flaky E2E failures in actions-blog/cloudflare/hmr tests. Made-with: Cursor * fix: propagate head metadata across ssr and prerender envs in dev (#16292) * fix: propagate head metadata across ssr and prerender envs in dev Signed-off-by: Patrick Linnane <patrick@linnane.io> * test(astro): cover head propagation through prerender env Signed-off-by: Patrick Linnane <patrick@linnane.io> --------- Signed-off-by: Patrick Linnane <patrick@linnane.io> * fix(assets): pass through images Sharp cannot decode instead of crashing (#16451) * fix(assets): pass through images Sharp cannot decode instead of crashing * test(assets): add test for animated AVIF pass-through * test(assets): add test for animated AVIF pass-through * fix(test): remove incorrect avif extension assertion * chore: add changeset for animated AVIF fix * feat(assets): add warning when Sharp cannot optimize unsupported image formats * chore: lint and whitespace * [ci] format * Update dependency @fastify/middie to v9.3.2 [SECURITY] (#16369) Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com> * perf(astro): skip session storage lookup if no cookie is set (#16540) * Fix defineLiveCollection interface loader typing (#16018) * Fix defineLiveCollection interface loader typing * Retrigger CI * Retrigger CI * [ci] format * Fix style compilation failure when importing components via tsconfig path aliases (#15994) * fix: resolve relative virtual module IDs in normalizeFilename for path alias styles When a component with a <style> tag is imported via a TypeScript path alias, certain environments (Windows + newer Node.js) can produce a relative virtual module ID (e.g. ./src/components/Foo.astro?astro&type=style). The load handler passed this through normalizeFilename to look up the compile metadata cache, but the function had no branch for ./-prefixed relative paths, so it returned the path unchanged instead of resolving it to an absolute path. This caused a cache miss and a build error. Adds a branch to resolve relative paths against root, matching the behavior used for /@fs and /path variants. Fixes #15963 * test: assert against emitted CSS file for path alias style regression test * fix(cloudflare): fix static assets and prerendered pages 404ing when `base` is configured. (#16277) * fix(cloudflare): static assets being in the wrong place * test(cloudflare): add tests * add changeset --------- Co-authored-by: Matthew Phillips <matthew@matthewphillips.info> * [ci] format * fix(test): update test-utils import from .js to .ts in .test.js files (#16560) * fix(frontmatter): preserve strings and comments when replacing top-le… (#16552) * fix(frontmatter): preserve strings and comments when replacing top-level return (#16551) * chore: add changeset for cloudflare KV namespace fix * fix(cloudflare): re-apply KV namespace merge fix after source revert --------- Co-authored-by: Matthew Phillips <matthewphillips@cloudflare.com> * fix: processing procedure for dynamic paths (#16144) * feat: test maching dynamic routes contain .html in their params * fix: processing procedure for dynamic paths * feat: changeset file for processing procedure for dynamic pahts * refactor(routing): move .html stripping logic from getParams to getProps * fix: UT of getParams function by fixing path mismatch error returning html file * fix: logic of removing .html extention * Apply suggestion from @Fryuni Co-authored-by: Luiz Ferraz <luiz@lferraz.com> * Apply suggestion from @Fryuni Co-authored-by: Luiz Ferraz <luiz@lferraz.com> * Apply suggestion from @Fryuni Co-authored-by: Luiz Ferraz <luiz@lferraz.com> --------- Co-authored-by: Matthew Phillips <matthew@matthewphillips.info> Co-authored-by: Luiz Ferraz <luiz@lferraz.com> Co-authored-by: Matthew Phillips <matthewphillips@cloudflare.com> * fix(css): preserve scope on nested & with lightningcss transformer (#16548) * fix(css): preserve scope on nested & with lightningcss transformer with `vite.css.transformer: 'lightningcss'`, scoped styles using `:where(& > ...)` (the shape tailwind v4's `space-x-*`, `space-y-*`, and `divide-*` expand to) put the scope attribute on the matched child instead of the parent. lightningcss flattened the nesting before `@astrojs/compiler` ran scope injection, so by then `:where(...)` was the leading compound and the injector prepended `[data-astro-cid-X]` as a new leading compound — constraining the wrong element. ask lightningcss to skip nesting lowering during the per-component `preprocessCSS` call (via `Features.Nesting` on a shallow-cloned config — non-mutating, safe under parallel compiles). vite's final pipeline still lowers nesting for the bundle. adds a regression test covering the reporter's exact shape. Fixes #16524 * docs(changeset): rewrite per astro guidelines --------- Co-authored-by: Matthew Phillips <matthewphillips@cloudflare.com> * Fixes @_@ not being stripped from CSS file names (#16264) Co-authored-by: Matthew Phillips <matthew@matthewphillips.info> Co-authored-by: Matthew Phillips <matthewphillips@cloudflare.com> * fix : astro image position prop bug (#16236) * feat: test of astro image position prop bug * fix: logic of getItem function * feat: changeset file * fix: create data-astro-image-pos attribute all time for path csp unit test * feat: another test of getImage function * fix: change set explanetion more clealy for users * Add: yaml file * chore: clean up changeset --------- Co-authored-by: Matthew Phillips <matthew@matthewphillips.info> Co-authored-by: Matthew Phillips <matthewphillips@cloudflare.com> * [ci] format * fix(build): exclude prerendered route styles from SSR manifest (#16517) Inline CSS for prerendered routes is dead weight in the SSR manifest: the prerendered HTML on disk already contains the <style> tags, and the SSR worker never renders these routes. Strip styles for prerendered routes from the SSR manifest while leaving the prerender manifest (and prerendered HTML) unchanged. Cuts SSR entry-chunk size on hybrid builds with build.inlineStylesheets: "always", reducing cold-start parse cost on Cloudflare Workers and similar platforms. * fix(prefetch): trigger tap strategy when clicking nested child elements (#16566) * fix(prefetch): trigger tap strategy when clicking nested child elements * fix(prefetch): trigger tap and hover strategies when clicking nested child elements * fix(astro): persist session delete without prior get/set (#16565) * fix(astro): persist session delete without prior get/set * est(e2e): sync collectLoads to avoid race with assertions * fix(astro): persist session delete without prior get/set * fix: route mismatch using trail slash never (#16516) * feat: test for route match fails when trailingSlash never * fix: root route matching with trailingSlash: 'never' and base path * feat: changeset file * fix: root route matching with trailingSlash 'never' and base path in dev server and rewrites The `normalizeRewritePathname` in rewrite.ts was returning '' (empty string) for root-path rewrites with a non-root base, and app.ts was converting the stripped pathname '/' to '' before route matching. Both relied on the old '^$' pattern for the index route. After the pattern.ts fix made the root pattern '^/$', these normalizations broke matching. Remove the '/' -> '' conversions so route.pattern.test('/') correctly matches the fixed '^/$' pattern in both direct requests and Astro.rewrite() calls * fix: add regression test for root path normalization with base --------- * [ci] format * [ci] release (#16545) Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com> * fix: resolve merge conflicts from main into next * fix: resolve merge issues from main into next - Add missing dependencies (get-tsconfig, jsonc-parser) and remove tsconfck (replaced on main by PR #16433 but deps were lost during merge) - Remove unused replaceTopLevelReturns export from vite-plugin-astro/utils.ts (function from main's PR #16552 not used by next's Rust compiler, fixes knip lint) - Update lightningcss-scoped-nesting test expectations for Rust compiler (next branch handles CSS scoping differently, test from PR #16548) - Format compile.ts (remove extra blank line) * chore: trigger CI * fix: add head-inject directive to propagated assets module for CSS injection * chore: update main-to-next merge * chore: retrigger CI * chore: retrigger CI --------- Signed-off-by: Patrick Linnane <patrick@linnane.io> Co-authored-by: Matthew Phillips <matthewphillips@cloudflare.com> Co-authored-by: Matthew Phillips <matthewp@users.noreply.github.com> Co-authored-by: Chan <101856681+enjoyandlove@users.noreply.github.com> Co-authored-by: knj <kenji.tomita1996@gmail.com> Co-authored-by: knj <ematipico@users.noreply.github.com> Co-authored-by: ocavue <ocavue@users.noreply.github.com> Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com> Co-authored-by: web-dev0521 <jasonpette1783@gmail.com> Co-authored-by: Rayan Salhab <r.salhab@aiyexpertsolutions.com> Co-authored-by: cyphercodes <cyphercodes@users.noreply.github.com> Co-authored-by: 0x K. <66915025+0xbejaxer@users.noreply.github.com> Co-authored-by: Patrick Linnane <patrick@linnane.io> Co-authored-by: Maxim Slobodchikov <93232189+maximslo@users.noreply.github.com> Co-authored-by: Matt Kane <m@mk.gg> Co-authored-by: Felmon <felmonon@gmail.com> Co-authored-by: Ossaid <imossaidquadri@gmail.com> Co-authored-by: Calvin Liang <me@calvin.sh> Co-authored-by: Matthew Phillips <matthew@matthewphillips.info> Co-authored-by: fkatsuhiro <113022468+fkatsuhiro@users.noreply.github.com> Co-authored-by: Luiz Ferraz <luiz@lferraz.com> Co-authored-by: Utpal Sen <utpalsen902@gmail.com> Co-authored-by: atsbob <98831687+atsbob@users.noreply.github.com> Co-authored-by: Adam Chalemian <adam@chal.net> Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

fix(astro): preserve CSS from imported partial pages

01986de

Treat top-level pages as CSS boundaries only when they are referenced exclusively by the virtual page module, so partial pages imported as components continue propagating transitive styles in production builds. Made-with: Cursor

0xbejaxer force-pushed the fix-16296-partial-css-boundary branch from 9a87942 to 01986de Compare April 20, 2026 18:50

github-actions Bot added the pkg: astro Related to the core `astro` package (scope) label Apr 20, 2026

0xbejaxer added 2 commits April 20, 2026 19:44

test(astro): fix partial CSS fixture component import path

68de140

Correct the regression fixture path so the partial page can resolve ResultsTable during build on CI. Made-with: Cursor

test(astro): make partial css assertion robust to minification

570a527

Assert that scoped ResultsTable selectors are present in extracted styles instead of matching a specific color token that can be minified differently across environments. Made-with: Cursor

0xbejaxer mentioned this pull request Apr 20, 2026

Breaking Change: CSS missing in production when using 'export const partial = true' (6.1.0+) #16296

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0xbejaxer and others added 3 commits April 21, 2026 07:39

Merge branch 'main' into fix-16296-partial-css-boundary

fb5212b

Merge branch 'main' into fix-16296-partial-css-boundary

c0449fc

chore: rerun CI after unrelated e2e flake

f22ad01

Trigger a fresh workflow run for PR withastro#16415 after unrelated flaky E2E failures in actions-blog/cloudflare/hmr tests. Made-with: Cursor

matthewp approved these changes May 1, 2026

View reviewed changes

matthewp merged commit 559c0fd into withastro:main May 1, 2026
28 checks passed

astrobot-houston mentioned this pull request May 1, 2026

[ci] release #16545

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fix: preserve CSS propagation for partial pages imported as components#16415

fix: preserve CSS propagation for partial pages imported as components#16415
matthewp merged 6 commits intowithastro:mainfrom
0xbejaxer:fix-16296-partial-css-boundary

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