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fix(css): join the rules a gathered @layer block leaves side by side - #22204
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A named `@layer` block gathered into an earlier sibling makes the earlier block's last rule and the incoming block's first rule neighbours, but the streamed path folded the bodies as text and never offered that pair the join two siblings are offered. Minifying the same sheet twice then joined them only on the second pass: over Tailwind 4 + daisyUI 5 the printer's own idempotence sweep reported a 75-byte drift. The collected path already joins the seam through `_joinRuleEntries`; the streamed one now does it with the span primitives the piece is keyed by, so both agree. Also read an at-rule between two rules `mergeDistantRules` would join for what its own rules declare, rather than taking it as declaring everything. A condition only narrows which elements read the block it holds, so what it can shadow is what its rules declare; `@layer` and anything whose declarations cannot be read still stand in the way whatever they say. Over the comparison fixtures that is -418 raw / -48 gzip on daisyUI, -151 raw on Foundation and -39 raw on Bulma, with nothing lost elsewhere. Gathering two blocks of one condition is left declined with the reason measured in place: it moves a body up into a rule merge's way, for +835 raw and +25 gzip bytes over daisyUI.
🦋 Changeset detectedLatest commit: b041bdb The changes in this PR will be included in the next version bump. This PR includes changesets to release 1 package
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## main #22204 +/- ##
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Coverage 94.98% 94.98%
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Files 747 747
Lines 104394 104438 +44
Branches 32157 32182 +25
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+ Hits 99154 99201 +47
+ Misses 5240 5237 -3
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In @.changeset/006-css-distant-merge-reads-conditions.md:
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The CLI flags are derived from the schema and their snapshot carries each option's description, so rewording `mergeDistantRules` left it stale in both the `optimization.minimize.css` and `optimization.minimizeOptions.css` entries. Cover the paths where the gathered seam declines the join as well: a first child that is an at-rule or carries a selector no list may take, an earlier rule whose own list may not be joined, a pair whose blocks differ, and a selector the grown list already carries.
Merging this PR will regress 2 benchmarks
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| Mode | Benchmark | BASE |
HEAD |
Efficiency | |
|---|---|---|---|---|---|
| ❌ | Memory | benchmark "common-libs", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' |
576.6 KB | 892.3 KB | -35.39% |
| ❌ | Memory | benchmark "asset-modules-bytes", scenario '{"name":"mode-production","mode":"production"}' |
6.2 MB | 8.2 MB | -24.86% |
| ⚡ | Memory | benchmark "future-defaults", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' |
294.9 KB | 160.5 KB | +83.8% |
| ⚡ | Simulation | benchmark "wasm-modules-sync", scenario '{"name":"mode-development","mode":"development"}' |
1,149.2 ms | 849 ms | +35.36% |
| ⚡ | Memory | benchmark "asset-modules-source", scenario '{"name":"mode-production","mode":"production"}' |
8.4 MB | 6.2 MB | +34.52% |
| ⚡ | Memory | benchmark "hmr", scenario '{"name":"mode-development-rebuild","mode":"development","watch":true}' |
970.7 KB | 793.3 KB | +22.36% |
Tip
Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.
Comparing fix/css-rule-merge-seams (b041bdb) with main (0af51c4)2
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Coverage Report |
This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [webpack](https://github.com/webpack/webpack) | [`5.111.1` → `5.112.0`](https://renovatebot.com/diffs/npm/webpack/5.111.1/5.112.0) |  |  | --- >⚠️ **Warning** > > Some dependencies could not be looked up. Check the [Dependency Dashboard](issues/99) for more information. --- ### Release Notes <details> <summary>webpack/webpack (webpack)</summary> ### [`v5.112.0`](https://github.com/webpack/webpack/blob/HEAD/CHANGELOG.md#51120) [Compare Source](webpack/webpack@v5.111.1...v5.112.0) ##### Minor Changes - Apply `plugins` set on a multi-configuration array to the `MultiCompiler`. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22702](webpack/webpack#22702)) - Add `optimization.minimize.css.dropOverriddenDeclarations`, dropping a declaration a later one overrides where no target is named. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22175](webpack/webpack#22175)) - Export more plugins under their scope, move eleven loose exports under theirs, deprecate the old, and expose `template.DependencyTemplate`, `module.NullFactory` and `util.makeSerializable`. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22261](webpack/webpack#22261)) - Let `util.makeSerializable` take several requests, current one first. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22340](webpack/webpack#22340)) - Emit the source map `scopes` field, so a debugger resolves imported ESM bindings by name. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​21999](webpack/webpack#21999)) - Add `library.entryExports: "all"` to expose the exports of every entry module. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22235](webpack/webpack#22235)) - Recognize a required `const` binding assigned to `exports` as a re-export. (by [@​hai-x](https://github.com/hai-x) in [#​22276](webpack/webpack#22276)) - Accept glob patterns in more path, module and file filter options. (by [@​hai-x](https://github.com/hai-x) in [#​22422](webpack/webpack#22422)) - Bundle a run of inline `<script>` tags into one chunk the page can inline. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22188](webpack/webpack#22188)) - Add `module.parser.javascript.topLevelThis` for classic-script `this` semantics. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22193](webpack/webpack#22193)) - Add `module.parser.html.chunkName` and a `webpackChunkName` comment for tags. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22200](webpack/webpack#22200)) - Add `include`/`exclude` version and request filters to shared modules. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22297](webpack/webpack#22297)) - Keep module side-effect information in ESM output as PURE annotations. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​21789](webpack/webpack#21789)) - Add `optimization.splitChunks.dedupDepth` to discover chunk intersections. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22240](webpack/webpack#22240)) - Add `optimization.minimizeOptions.json`, on by default with `futureDefaults`. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22286](webpack/webpack#22286)) - Add `SSRManifestPlugin` and fix server-rendered CSS collection and adoption. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​21913](webpack/webpack#21913)) - Add an `ignore` hook to `output.copy` and keep unfollowed `from` symlinks. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22216](webpack/webpack#22216)) - Add `optimization.minimize.css.convertApproximateColors`. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22157](webpack/webpack#22157)) - Add XML parsing and SVG/XML minification with data URLs and attribute sorting. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22269](webpack/webpack#22269)) - Extract CSS/HTML license comments like JS and safely shorten CSS gradients. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22408](webpack/webpack#22408)) - Resolve an async `DefinePlugin.runtimeValue` over an async `beforeParse` hook. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22210](webpack/webpack#22210)) - Add CSS `customMedia`/`customSelectors` minimize options; resolve chained names. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22360](webpack/webpack#22360)) - Rename the `Harmony*` names to `ESM*` and deprecate the old spellings. (by [@​hai-x](https://github.com/hai-x) in [#​22283](webpack/webpack#22283)) - Reduce `css.syntax`/`html.syntax` to `parser`, `printer`, `SourceProcessor` with one node path. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22233](webpack/webpack#22233)) - Add a JavaScript `SyntaxTree` read like the CSS one, and `toEstreeObject`. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22608](webpack/webpack#22608)) - Fix minified code that threw, and add `pure_conversions` and `pure_heritage`. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22473](webpack/webpack#22473)) - Shorten more CSS values and selectors, fold longhands, order declarations and gather layer blocks. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22442](webpack/webpack#22442)) - Add `optimization.minimize.css.charset`; `false` drops `@charset` for UTF-8 CSS. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22632](webpack/webpack#22632)) ##### Patch Changes - Join rules a gathered `@layer` leaves adjacent, and an at-rule with a later one (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22204](webpack/webpack#22204)) stating the same condition; read what a condition declares. - Read escaped CSS names and functions as spelled, and minify them unescaped. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22262](webpack/webpack#22262)) - Minify JavaScript, CSS and HTML assets whose names carry a `#fragment`. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22277](webpack/webpack#22277)) - Require `minimizer-webpack-plugin` 5.12, so inline scripts in HTML minify again. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22296](webpack/webpack#22296)) - Minify the attributes of an HTML tag without rewriting the template in it. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22166](webpack/webpack#22166)) - Order joined at-rule selector lists and gather a repeated large `@layer` block. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22224](webpack/webpack#22224)) - Preserve case-sensitive template identifiers when minifying HTML tag attributes. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22177](webpack/webpack#22177)) - Match Acorn's strict directives, Unicode identifiers and expression validation. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22185](webpack/webpack#22185)) - Skip concatenating modules when `optimization.providedExports` is disabled. (by [@​hai-x](https://github.com/hai-x) in [#​22410](webpack/webpack#22410)) - Join rules a nesting lowering or duplicate drop left for a second pass. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22268](webpack/webpack#22268)) - Write U+00A0 in a minified HTML attribute as the character, not ` `. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22208](webpack/webpack#22208)) - Escape a foreign `<script>` or `<style>` body, which is character data. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22233](webpack/webpack#22233)) - Name the runtime module whose generation fails while hashing. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22203](webpack/webpack#22203)) - Rebuild a module in watch when its missing unused dependencies swap. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22693](webpack/webpack#22693)) - Rebuild in watch mode when a file is deleted while a build is running. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22650](webpack/webpack#22650)) - Take out the declaration a lowered shorthand writes over, which its source spelling made look like a fallback. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22270](webpack/webpack#22270)) - Read a foreign `<script>` or `<style>` body as character data, not as raw text. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22258](webpack/webpack#22258)) - Keep an inline `<style>` body as written when rebuilding a page webpack emitted. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22265](webpack/webpack#22265)) - Fix minified HTML for `style` spellings, CSS quotes, `<noscript>` and a BOM. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22370](webpack/webpack#22370)) - Record a build dependency required through a spread on Bun. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22230](webpack/webpack#22230)) - Write a nested selector opening on a combinator against its parent the way the printer writes one. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22271](webpack/webpack#22271)) - Fix missing async stylesheets with a shared runtime. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22659](webpack/webpack#22659)) - Support deferred imports introduced by hot updates. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22668](webpack/webpack#22668)) - Fix trailing commas in `require.resolve()` and `require.resolveWeak()` calls. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22658](webpack/webpack#22658)) - Keep regular expressions, functions and plugins distinct in resolver caches. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22667](webpack/webpack#22667)) - Order the list a lowered nested selector lands in on what is written, not on what was. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22287](webpack/webpack#22287)) - Hoist a vendor-prefixed nested rule for a target that reads no nesting. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22308](webpack/webpack#22308)) - Name a hoisted nested rule in the dark-scheme copy it writes. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22318](webpack/webpack#22318)) - Minify data: URL payloads in HTML attributes and `new URL`, and web manifests. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22300](webpack/webpack#22300)) - fold a fallback's colors over the author's arguments, and print with (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22314](webpack/webpack#22314)) `recurseBlocks: false` rather than throwing - Read a regular expression repeating a capture group name in linear time. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22187](webpack/webpack#22187)) - Make lazy barrels defer import declarations and keep no deferral across compilations. (by [@​hai-x](https://github.com/hai-x) in [#​22359](webpack/webpack#22359)) - Invalidate unaffected caches when connection activity or async status changes. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22431](webpack/webpack#22431)) - Order concatenated re-exports deterministically when their source order ties. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22697](webpack/webpack#22697)) - Regenerate a module's exports when a require() cycle forms or breaks around it. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22644](webpack/webpack#22644)) - Recompute re-exports, code and warnings when a module goes missing or returns. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22432](webpack/webpack#22432)) - Preserve loader resolution dependencies across cached rebuilds. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22430](webpack/webpack#22430)) - Read unwatched changes afresh and wait for restarted watch compilers to finish. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22646](webpack/webpack#22646)) - Parse loader output for `.wasm` as JavaScript when async wasm is auto-enabled. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22556](webpack/webpack#22556)) - Remove modules an async chunk inherits from a named parent chunk grown later. (by [@​hai-x](https://github.com/hai-x) in [#​22555](webpack/webpack#22555)) - Fix JavaScript minifier crashes, altered behavior, lost comments, unparsable output and null source map sources, including parameter aliases, ESTree trees and preserved names, and stop it writing into the caller's parse options. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22352](webpack/webpack#22352)) - Preserve the source phase of dynamic WebAssembly import contexts. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22604](webpack/webpack#22604)) - Await every async entry before resolving an ESM library import. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22617](webpack/webpack#22617)) - Keep unknown `import.meta` properties per module, alike for aliases and direct use. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22618](webpack/webpack#22618)) - Return WebAssembly modules directly from eager and weak source imports. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22606](webpack/webpack#22606)) - Handle missing ESM hot update manifests in Node.js without failing HMR checks. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22613](webpack/webpack#22613)) - Speed up JavaScript parsing: comment lookup, the tokenizer and the grammar. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22179](webpack/webpack#22179)) - Name a core module external by its key whichever spelling the code uses. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22565](webpack/webpack#22565)) - Prefix and drop 2009 flexbox names, keeping them where a box lays out by them. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22320](webpack/webpack#22320)) - Keep `initial` where Gecko or WebKit reads the property's keyword apart. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22176](webpack/webpack#22176)) - Fold `calc()` as lightningcss does, keeping it where a bare value is refused. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22205](webpack/webpack#22205)) - Keep a `color-mix()` whose hue rests on a gray's conversion residue. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22198](webpack/webpack#22198)) - Keep a shorthand's initial keyword where it parts two keywords of another slot. (by [@​dependabot](https://github.com/apps/dependabot) in [#​22518](webpack/webpack#22518)) - Group `lib/` and `lib/dependencies/` sources into directories. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22118](webpack/webpack#22118)) - Treat a browserslist target given at a bare major version (e.g. `safari 10`) as `<major>.0` when a feature's first supported version is a `[major, minor]` pair, so it is no longer reported as unsupported. (by [@​Eshiv-Pandey](https://github.com/Eshiv-Pandey) in [#​22280](webpack/webpack#22280)) - Keep the last HMR update with `output.clean`; stop rechecking removed files. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22339](webpack/webpack#22339)) - Read and print a CSS backslash as the spec does, and a NUL as U+FFFD. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22201](webpack/webpack#22201)) - Make minified CSS and HTML stable on a second pass, even for truncated input. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22290](webpack/webpack#22290)) - Minify a merged `<style>` run as one sheet, closing each where its input ended. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22302](webpack/webpack#22302)) - Minify JavaScript with webpack's printer under `futureDefaults`, `terser` otherwise. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22217](webpack/webpack#22217)) - Preserve `wrappedContextRegExp` flags when rebuilding context request matchers. (by [@​Eshiv-Pandey](https://github.com/Eshiv-Pandey) in [#​22303](webpack/webpack#22303)) - Minify CSS `@supports`, `@import` and `@custom-media` conditions, and exponent numbers. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22347](webpack/webpack#22347)) - Fold unitless `hsl()`/`hwb()` channels, and only where the separators are valid. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22242](webpack/webpack#22242)) - Split `@value` imports on the `from` keyword, not a substring in the path. (by [@​Eshiv-Pandey](https://github.com/Eshiv-Pandey) in [#​22306](webpack/webpack#22306)) - Destructure a dotted `DefinePlugin` key whose value is falsy or a runtimeValue. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22215](webpack/webpack#22215)) - Make `Stats.hasErrors()` read errors through the `processErrors` hook (via `getErrors()`), matching `hasWarnings()`, so a plugin that filters errors out of the hook is no longer contradicted by `hasErrors()`. (by [@​Eshiv-Pandey](https://github.com/Eshiv-Pandey) in [#​22281](webpack/webpack#22281)) - Allow wrapping an external concatenated module, now asked of the module itself, and re-exporting a JSON or asset `default` as a namespace object. (by [@​hai-x](https://github.com/hai-x) in [#​22226](webpack/webpack#22226)) - Match `urlHints` rules written with `and`, `or`, `not` and `glob` conditions; profile hook map taps, such as resolver and parser hooks, in `ProfilingPlugin`; report `import.meta` option errors inside `require.ensure` callbacks, not crash; and replace `any`, `object` and `Function` with precise types in the type definitions. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22681](webpack/webpack#22681)) - Reduce CSS and HTML build time and memory allocation. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22135](webpack/webpack#22135)) - Reuse free names instead of re-parsing modules for the entry IIFE rename. (by [@​hai-x](https://github.com/hai-x) in [#​22206](webpack/webpack#22206)) - Release each module's ast once scope-analysed, and encode each export path once. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22241](webpack/webpack#22241)) - Export a module library entry's default expression as its own binding, and keep (by [@​hai-x](https://github.com/hai-x) in [#​22227](webpack/webpack#22227)) the export helpers where the entry is not inlined. - Give a wrapped concatenated body the same function header as a module factory. (by [@​hai-x](https://github.com/hai-x) in [#​22254](webpack/webpack#22254)) - Skip reading every asset when no content hash is named. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22256](webpack/webpack#22256)) - Cut graph, cached set, lazy barrel and ESM import memory and allocations. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22289](webpack/webpack#22289)) - Stop a module source from being held as both a string and a buffer. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22294](webpack/webpack#22294)) - Read the browserslist data and options schema only when a build needs them. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22324](webpack/webpack#22324)) - Release the eval devtool's cached module sources after wrapping them. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22358](webpack/webpack#22358)) - Release the rendered module sources after emitting the chunks. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22365](webpack/webpack#22365)) - Cut the peak memory and time of minifying through webpack's printer. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22368](webpack/webpack#22368)) - Shrink minified JS: unwrap IIFEs, fold calls, drop dead code, split arrays. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22393](webpack/webpack#22393)) - Cut JavaScript minifier time and memory; keep token positions in large inputs. (by [@​bjohansebas](https://github.com/bjohansebas) in [#​22329](webpack/webpack#22329)) - Keep the `calc()` around a `steps()` count `jump-none` would reject bare. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22168](webpack/webpack#22168)) - Split the CSS syntax module into a parser file and a printer file. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22222](webpack/webpack#22222)) - Update enhanced-resolve to 5.26.0. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22358](webpack/webpack#22358)) - Update watchpack to 2.6.1. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22670](webpack/webpack#22670)) - Split the HTML syntax module into a parser file and a printer file. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22223](webpack/webpack#22223)) - Rename classes in `lib/` so each says what it does and no two share a name. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22361](webpack/webpack#22361)) - Keep the remote fallback index aligned with registered container externals when an `internal ` external precedes a real one. (by [@​Eshiv-Pandey](https://github.com/Eshiv-Pandey) in [#​22362](webpack/webpack#22362)) - Stop a minified inlined chunk leaving a doubled `;` in its `<script>`. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22370](webpack/webpack#22370)) - Stop `mergeDistantRules` mangling rules or reordering `all`, and merge more. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22370](webpack/webpack#22370)) - Minify by parsing with webpack's own parser rather than terser's. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22397](webpack/webpack#22397)) - Read JavaScript with webpack's parser alone when minifying, refusing early errors. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22397](webpack/webpack#22397)) - Parse an `assert(...)` call after an import with no semicolon, and a regular expression after `yield` in a generator method. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22406](webpack/webpack#22406)) - Keep the private names a direct `eval` reads when mangling. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22412](webpack/webpack#22412)) - Keep a class dropped for its effects where they read a private name it declares. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22421](webpack/webpack#22421)) - Parenthesize the right side of a private `in`, a `yield`, `await`, private `in` or optional chain tagging a template, and a `let` or `async` starting a statement or loop head, where the minifier printed code that no longer parsed or read otherwise. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22437](webpack/webpack#22437)) - Keep a name a parameter list or catch parameter reads from resolving to what the function body or catch block declares, which the minifier renamed or dropped as unused. (by [@​aryanraj45](https://github.com/aryanraj45) in [#​22439](webpack/webpack#22439)) - Scope and export a CSS Modules `@value` the same way whether local or imported. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22443](webpack/webpack#22443)) - Keep CSS `border: none` and gradient fallbacks for units a target cannot read. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22567](webpack/webpack#22567)) - Keep minified CSS safe for older browsers; drop dead fallbacks and overrides. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22696](webpack/webpack#22696)) - Keep CSS rules apart from a neighbor whose selector no browser parses. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22634](webpack/webpack#22634)) - Keep an `:nth-*()` argument with a space after its sign as written. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22700](webpack/webpack#22700)) - Keep minified CSS readable by browsers the compat data does not cover. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22701](webpack/webpack#22701)) - Keep a module its chunk still needs after `compilation.rebuildModule()`. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22705](webpack/webpack#22705)) - Keep a CSS rule nested under a selector opening on a combinator when lowering. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22707](webpack/webpack#22707)) - Use module paths for webpack's built-in minimizers so parallel minification can load them directly in workers instead of serializing their function sources. (by [@​xiaoxiaojx](https://github.com/xiaoxiaojx) in [#​22309](webpack/webpack#22309)) - Keep stats from an earlier build readable after a later build no longer has one of their modules. (by [@​alexander-akait](https://github.com/alexander-akait) in [#​22695](webpack/webpack#22695)) </details> --- ### Configuration 📅 **Schedule**: (UTC) - Branch creation - "before 9am on tuesday" - Automerge - At any time (no schedule defined) 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box --- This PR has been generated by [Mend Renovate CLI](https://github.com/renovatebot/renovate). <!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0NC4xNjcuMCIsInVwZGF0ZWRJblZlciI6IjQ0LjE2Ny4wIiwidGFyZ2V0QnJhbmNoIjoiZGV2ZWxvcCIsImxhYmVscyI6WyJkZXBlbmRlbmNpZXMiLCJyZW5vdmF0ZSJdfQ==--> Reviewed-on: https://code.futo.org/harbor/harbor/pulls/1941 Reviewed-by: Mark Harding <mark@futo.org>
Summary
Gathering a named
@layerblock into an earlier sibling makes that block's last rule and the incoming block's first rule neighbours. The collected path offers that pair the join through_joinRuleEntries; the streamed path folded the bodies as text and never did, so the same sheet minified twice joined them only on the second pass — the printer's own idempotence sweep reported a 75-byte drift over Tailwind 4 + daisyUI 5. The streamed path now joins the seam with the span primitives its piece is keyed by, taking the sweep to 25 bytes and cutting daisyUI's output by 50.Also reads an at-rule between two rules
mergeDistantRuleswould join for what its own rules declare, rather than taking it as declaring everything: a condition only narrows which elements read the block it holds.@layerand anything whose declarations cannot be read still stand in the way whatever they say. Over thebenchmark:css-minifiersfixtures that is -418 raw / -48 gzip on daisyUI, -151 raw on Foundation and -39 raw on Bulma, with no class or rule lost anywhere. Gathering two blocks of one condition is left declined with the measurement in place: it moves a body up into a later rule merge's way, for +835 raw and +25 gzip bytes over daisyUI.The remaining 25 bytes are a streaming limit rather than an oversight: a
@layerblock past_STREAM_MIN_NODEShas its body written out before the gather can know it repeats a layer, so it can be folded into but never folded backwards.What kind of change does this PR introduce?
fix
Did you add tests for your changes?
Yes —
test/unitCases/CssSyntax.unittest.js(a streamed-gather seam case under "block streaming", and the widenedmergeDistantRulesgates), andtest/configCases/css/minimize-merge-distant-rulesfor the condition reading.Does this PR introduce a breaking change?
No. Default output changes only where a streamed
@layergather happens; the rest of the comparison corpus is byte-identical.If relevant, what needs to be documented once your changes are merged or what have you already documented?
The
optimization.minimize.css.mergeDistantRulesdescription inschemas/WebpackOptions.jsonis updated to say that a condition between counts for what its own rules declare; no site docs change.Use of AI
Claude Code was used to root-cause the sweep finding, write the change and its tests, and take the measurements quoted above. Every claim here comes from a run on this branch: the invariant sweep,
ConfigTestCases/ConfigCacheTestCasesforcss, the CSS unit tests, andtest:syntax-equivalenceagainst Chromium.🤖 Generated with Claude Code
https://claude.ai/code/session_018tNx7sU4SbnKFhFeofDVr5
Generated by Claude Code
Summary by CodeRabbit
@mediaand@supportswhen declarations do not conflict.@layerblocks while preserving cascade behavior.