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css: store a calc() sum as one flat list of terms, and never drop or order a percentage of a length - #45442
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css: store a calc() sum as one flat list of terms, and never drop or order a percentage of a length#45442robobun wants to merge 9 commits into
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Status: the fix is in this PR (#45442). How it was reproduced, on a release build of main at f0c6cbc:
With this PR each of these takes 0.2 s of CPU or less, and the peak memory is 26 MB. |
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Updated 4:49 AM PT - Oct 21st, 2026
❌ @robobun, your commit d764f76 has 2 failures in
🧪 To try this PR locally: bunx bun-pr 45442That installs a local version of the PR into your bun-45442 --bun |
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WalkthroughCalc sums now use term lists and running accumulation. Parsing combines compatible terms and removes zero terms. Serialization handles each term. Regression tests cover normalization, minification, and long sums across CSS build and runtime paths. ChangesCSS calc sum accumulation
Suggested reviewers: Priority: ⬆️ High Merge Risk: ⚪ Minimal · up to
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The title clearly and concisely identifies the main change: replacing binary calc() sums with a flat term list and preserving length percentages. |
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The description clearly explains the problem, implementation, behavior changes, performance impact, limitations, and verification results. It does not use the template headings "What does this PR do?"… |
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The description clearly explains the problem, implementation, behavior changes, performance impact, limitations, and verification results. It does not use the template headings "What does this PR do?" and "How did you verify your code works?", but it provides the required information in equivalent sections.
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Beyond the inline findings, I also checked the value-index update in SumBuilder::order_first_two (src/css/values/calc.rs:1302-1306) for an out-of-bounds index: the swap only runs when exactly one of the first two terms is a value, so the first recorded position is always 0 or 1 and 1 - *at stays in range. I also checked that the bounded scan in find_value_to_add stays at most SCAN_MAX reads before the index is built.
Extended reasoning...
The change replaces the binary-tree Calc::Sum in src/css/values/calc.rs with a flat term list and a single SumBuilder fold, with matching trait changes in length.rs and percentage.rs and new tests in test/js/bun/css. It touches no security-sensitive surface beyond parsing user-supplied CSS. Inline findings cover an output-semantics change for cancelled percentages, a quadratic Vec::remove path under nested brackets, and test-harness issues, so a human still needs to weigh in.
Findings marked 🟡 are optional suggestions and need no follow-up push.
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…brackets Test only. It passes on main. - The 43 rows of lightningcss v1.33.0 test_calc (src/lib.rs:8064-8169). Main passes 41 of them. The other two are todo. - The printed form of a sum that has no sum as an operand: where a value folds, where a term that cancels goes, when the first two terms change places. No test pinned these.
A calc() sum was a binary tree with one Box level for each term that did not fold. Each pass over a value recursed once for each term, so a long sum ran a bundler thread out of stack. The two folds (DimensionPercentage::add_recursive, Length::try_add) cloned the tree at each level, so a sum of a few hundred terms took seconds. Calc::Sum now holds one list, SumTerms. Only its own module builds one, and Calc::sum splices a term that is a sum, so a sum cannot hold a sum. One fold, SumBuilder, replaces the two copies. Each calc() type says through CalcValue::add_to_sum which of the two ways it adds. An operand that is itself a sum (brackets, a nested calc()) now prints as its terms: calc(100% - (1rem + 2px)) is calc(100% - 1rem - 2px), before calc(100% + -1rem - 2px). A sum with no such operand prints as before.
`SumBuilder` kept the positions of its values in a `Vec` that four places changed by hand. Its `remove` was compiled once for each value type, and most of it does not use the type (mordant: `generic_body_not_generic`). `ValuePositions` owns the positions now. `CalcValue::from_calc` had no caller left for `Length` and `DimensionPercentage`, which do not add through `add_values`. It moves to `ScalarCalcValue`, the trait of the four types that cannot hold a sum. Tests: a fixture that needs the positions (without them, 45,000 values after 45,000 terms take more than 60 s in a debug build), a row for the order of the first two terms after a sum operand, rows with browser targets for the `is_compatible` arm of a sum, and two rows for the types that cannot hold a sum.
A calc() sum left out each value of zero, and min(), max(), clamp(), round(), mod(), rem() and hypot() read two percentages as two numbers. Both are wrong for a percentage of a length, because what it refers to is not known at parse time (CSS Values 4, simplification): - It can refer to nothing. Then the value is `auto`, also at `0%`. So `height: calc(10% + 2px - 10%)` printed as `height: 2px` did not lay out like its source. - It can refer to a size below zero, as in `background-position`. Then `20%` is less than `10%`, and `max(0%, 20%)` is not `20%`. `dim_pct_protocol!` now takes one fact for each type, `percentage_basis_known`. For a length-percentage it is false: a sum keeps `0%` (`CalcValue::zero_in_sum`), and two percentages have no order and do not combine in a math function. For an angle-percentage it is true, and nothing changes. A length of zero is left out as before. A sum that is the only argument of min() or max() is now printed in calc(), as in #38654, and in hypot() it stays in hypot(). Before, it was printed with no math function around it, which is not valid CSS. A kept `0%` makes that argument a sum more often.
Twenty builds of a 1.2 GB debug binary at once came close to the 5 s of a test in a debug build. The sums that take the same command are now rules of one stylesheet, and each test checks its own rule.
… clones A debug build with ASAN takes 336 MB for this build and took 2,005 MB with the clones. The bound for debug and ASAN builds is now 640 MB, not 1,024 MB.
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I re-reviewed the latest push and found no bugs; the earlier inline findings are addressed in the code (a cancelled percentage of a length now stays as 0%, the memory fixture goes through runCommandMaxRSS, and its debug/ASAN bound of 640 MB sits below the unfixed peak). Because this rewrites the Calc::Sum representation and changes minified output for some real stylesheets, and the description leaves the zero-length-beside-percentage rows as an open question, a maintainer look is still worthwhile.
What was reviewed:
Calc::sumin the privatesummodule: flattening of nested sums,zero_in_sumretention of0%, collapse to one term orNumber(0.0); no path builds aSumoutside the module.SumBuilder/RunningSumfold and theValuePositionsindex pastSCAN_MAX, against the old pairwiseaddbehaviour;parse_min_max/parse_hypotwrapping of a lone sum or product.dim_pct_protocol!withpercentage_basis_known: falseforLengthValue, so percentage-vs-percentage clamp/min/max no longer fold.- The new subprocess tests: pipes drained concurrently, bounds branch on
isDebug/isASAN, children killed inafterAll.
Extended reasoning...
The change rewrites the calc() sum representation in src/css/values/calc.rs (binary tree to a flat SumTerms list with a SumBuilder fold), removes the pairwise add code from length.rs and percentage.rs, and adds ~680 lines of tests across css.test.ts and a new calc-long-sum.test.ts. It touches no security-sensitive surface; it is a CSS parser performance and correctness change reachable from bun build, bun pm diff and Bun.color. Deferral rather than approval is driven by the size and complexity of the rewrite, the intentional minified-output changes to real stylesheets, and the author's explicit open question for a maintainer about which zero-length rows to pin. The latest commits addressed every earlier inline finding and this run's hunt ended with no new findings.
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#46145 carries the wrap for a one-argument
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… and CLI (#46021) ### What does this PR do? Hardening. This collects the open pull requests that fix a crash in Bun into one change, and fixes about 20 more crashes that had no pull request. "Crash" here means a segfault, a Rust panic, an abort, a failed assertion, memory corruption that a sanitizer reports, a native stack overflow, or an exception that ends the process and that the program can't catch. With this PR those cases throw a normal error, print a normal CLI error and exit 1, or just work. 306 pull requests are included: 227 whole, and 79 cut down to the crash fix where the rest was a refactor, a feature or a behavior change. Each one was checked against current `main` first. 45 more turned out to be fixed already, and 17 were duplicates. The full list is at the bottom. #### Crashes you could hit in normal use - **`bun build` with macros and a `.env` file crashed at random.** In a repro with many macro modules, more than a third of the builds crashed. Now 3,000 of 3,000 produce the right bundle. (#45960) - **`bun run` and `bunx` aborted if a signal arrived while the child was being spawned.** (#38926, #45965) - **`bun build --compile ./index.js ./public/*` panicked** if an embedded file's name wasn't valid UTF-8. - **A truncated or corrupted compiled executable** died with SIGBUS or a panic at startup. It now prints an error. (#31787, #38251, #41360) - **Dev server:** several `Option::unwrap()` panics after a failed or deleted import (#38046, #44744, #44746), a segfault when an `onLoad` plugin throws while another bundle is queued, a request that hung and then panicked with `bundle active`, and `server.stop()` that never resolved after a client aborted a waiting request. - **`Bun.serve`:** `server.fetch(url, { headers: new Headers() })` followed by a GC segfaulted (#40888). Routes were used after free after `server.reload()` with `tls.serverName` (#38636). - **`text()` and `json()` on a stream of string chunks** could abort the process, a regression in 1.4.0. (#44269) - **`Bun.Transpiler` with `exports.eliminate` or `exports.replace`** aborted on `export default 1` and on most re-export clauses. (#44137) - **A decorated `declare` field in a class expression** with `experimentalDecorators` panicked. (#38095) - **YAML and JSON5 files with a key that isn't a string** panicked with `--no-bundle` and in `Bun.Transpiler`. (#41827) - **`Bun.FileSystemRouter`:** reading `.params` segfaulted when a rejected route candidate left its parameters behind. (#39290, #39291) - **Native addons that call `uv_async_*`, `uv_timer_*`, `uv_idle_*`, `uv_prepare_*`, `uv_check_*`, `uv_queue_work` or `uv_cwd`** aborted with "unsupported uv function" on Linux and macOS. They're implemented now. (#36609, #39652, #39892) - **`--watch` and `--hot`** panicked when the system was out of inotify instances or file descriptors, or when the reload `exec` failed. They print an error now. (#39629, #39975, #44837) - **Paths longer than the path buffer** panicked in `bun install`, the resolver, the bundler, `--compile`, `tsconfig.json` `paths` and `baseUrl`, `package.json` `main` and `sideEffects`, `bun run --filter`, `bun pm diff`, source maps and snapshots. They're ordinary errors now, or they work. (#36340, #37529, #39104, #39650, #43067) - **A Worker that creates a `ShadowRealm` and imports `node:worker_threads` in it** segfaulted. - **`structuredClone` or `postMessage` of an X25519 key** gave an object that aborted the process when read. (#45624) - **`node:stream` web adapters and `node:http2`** could end the process with an exception that no handler could catch. (#45076, #45975) - **Windows:** a watcher panic in a burst of file changes (#44344), a segfault after the machine resumes from sleep (#33015), crashes in the shell's pipe reader (#39638, #43606), and addons that import from `node.exe` without the delay-load hook (#35618). Most of the rest needs unusual input: strings near the 2 GiB limit, buffers that another thread or a getter resizes or detaches in the middle of a call, `worker.terminate()` at a bad moment, running out of memory or file descriptors, very deep nesting, or hostile arguments to `bun:ffi`, `node:vm` and `bun:sqlite`. #### Behavior changes Things that didn't crash before and behave differently now: - `new` on native functions that aren't constructors throws a `TypeError`, as in Node: `util.types.*`, `buffer.isAscii`, `isUtf8`, `transcode`, `resolveObjectURL`, `bun:jsc` exports, `cc()` symbols. It used to return the call's result. They also stop printing as `[class hostname]`. (#34575) - `` $`cmd` `` throws `ERR_INVALID_ARG_VALUE` if an environment variable's name or value contains a NUL byte. It used to cut the value at the NUL. (#44981) - `cc()` functions throw a `TypeError` for arguments that used to reach C as garbage, and `read.*(ptr, NaN)` throws. (#37989, #38057, #40773) - As PID 1, `bun` exits with 128 + the signal number on Ctrl+C or `docker stop`. (#38877) - A `NODE_MODULE` addon that's already loaded by the main thread throws `ERR_DLOPEN_FAILED` when a live Worker loads it too, as in Node. (#39968) - An exception from a `node:vm` context reaches `uncaughtException` handlers. (#39992) `vm.constants.DONT_CONTEXTIFY` returns the real global proxy. (#34623) - `createPrivateKey` rejects an EC JWK whose private value doesn't match its public point. (#33752) - `@dec static {}` is a syntax error, as in TypeScript and esbuild. (#44883) - `clearTimeout` ignores 0 and negative ids, and timer ids no longer wrap. (#44771) - HEAD for a `Response` whose body is an S3-backed `Blob` reports the length that GET sends. (#44734) - `bun:sqlite` and `node:sqlite`: if `iterate()` left a write unfinished on a connection that has a hook, a user function or an authorizer, the write is finished on the connection's next call instead of during garbage collection. If the database is gone too, it's rolled back. - `bun test --bail` runs exit listeners and closes SQLite databases. (#39010) - Dev server: a request for a client script waits while a bundle is in flight (#42733), query strings reach framework routes (#33232), and a request gets a 500 instead of hanging when plugins fail (#36812). #### File formats - `.jsc` bytecode files get a 24-byte footer so they can be verified before decoding. Files from an older Bun are ignored and the source is parsed instead. (#39396) - `node:vm` `cachedData` gets an 8-byte checksum. A blob from an older Bun is rejected, which the API allows. (#32839) - The built-in modules section of a compiled executable changes from format 1 to 2 and carries an engine stamp. (#44907) #### Performance Measured in instructions per operation on release builds of this branch and its base, with an A/A run for the noise floor (0.0 to 0.2 %). No change: `Bun.serve`, `node:http`, WebSocket echo and publish, `bun build` of 3,807 modules, `bun run` with 2,000 imports, `readdir` / `Glob` / `fs.cp` over 23,689 entries, startup and RSS. The binary grows by 176 KB (0.17 %). | Faster | Instructions | | --- | --- | | WebSocket echo of a 1 MB non-ASCII text message | −72 % | | `Bun.inspect` of a large non-ASCII string | −39 % | | `Bun.markdown.html` on large non-ASCII input | −33 % | | `` $`cmd` `` with 300 environment variables | −6 % | | `fs.readSync` | −5 % | | `TextEncoder.encodeInto`, short ASCII strings | −4 % | | async `crypto.pbkdf2`, 16-byte inputs | −17 % | | Slower | Instructions | Why | | --- | --- | --- | | `cc()` calls | +5 to +51 per call | Argument count and type checks, and a check for `close()` (#37989, #38057, #43802, #44921). `dlopen()` calls don't change | | `process.env.X = v` | 38 → 593 per write | Writes aren't cached. Reads don't change (#38871) | | async `crypto.pbkdf2`, inputs of 1 KB or more | +4 to +9 % | Password and salt are copied (#40554) | | `bun build` with an object `--define` used thousands of times | +4.5 % | The object is copied per use (#45969) | #### Not included - Fixes that need a WebKit change: #39967, #42534, #42982, #43764, #43786, #44226. #42185 too: a typed array that has no `ArrayBuffer` yet can't be pinned, so `view.buffer.transfer()` during an async call can still free its bytes. Creating the `ArrayBuffer` up front costs 7 to 12 % on every async `fs` call, so the fix belongs in JSC: an `ArrayBuffer` created while the view is borrowed should start out pinned. - #45442 (`calc()` sums as a flat list): it changes minified output for real stylesheets to survive a `calc()` with 25,000 terms. It deserves its own review. - #40023 (Windows event loop redesign), #29928 (Windows exit path), #40534, #43963, #39571, #42904, #42834, #36355, #43266: refactors or features whose crash is already covered or isn't a crash. - The pull requests marked *(crash fix only)* below should stay open for their other half. ### How did you verify your code works? - **Tests.** Every fix has a test that fails on `main` (a release or an ASAN build) and passes on this branch, except where that isn't practical: code that only runs on Windows or macOS, inputs that need several GB of memory, and a few rare races. Those were checked by hand or by reading. - **Stored repro scripts.** 230 crash repros ran on release and ASAN builds of this branch and of `main`, side by side. Release: 88 no longer crash. ASAN: 106 no longer crash. None crashes that didn't before. What still crashes needs WebKit, is SQLite's own bug, or isn't a crash. The ASAN number is from a later commit than the release number. - **Dev server.** Because one fix makes requests wait, 2,171 generated programs ran random interleavings of edits, build errors, failing plugins, reloads, stops and disconnects with about 120,000 requests. No request hung, was answered twice or got a stale body. `main` hung in 82 of 1,161 programs. This also found the four dev server bugs listed above. - **Path helpers.** 336,000 boundary cases with buffers of exactly the computed size, and 12,003 random calls through 30 JS APIs on an ASAN build, compared with `main`. No sanitizer report, and the results match wherever `main` doesn't panic. - **What worked on 1.4.3 still works.** Reviewers compared behavior with 1.4.3 and took out what changed it: for example an output directory layout change for 9 or more entry points, a `server.reload()` change, and a changed error message for `import("file:///50%deposit.ts")`. - **Not run locally:** the Windows, macOS and FreeBSD code paths. CI compiles and tests them. ### Included pull requests **Bundler, transpiler, CSS, macros** (33) - #33881 bundler: allocate wrapper_ref for CommonJS modules with no non-hoistable statements - #35055 Bun.build plugins: handle filter RegExp flags beyond i/m/v - #37769 bundler: fail the build instead of panicking when the bundle thread cannot create its waker - #37784 bundler: copy inlined env values into the define arena, and give each Bun.build its own env copy *(crash fix only)* - #37858 bundler: fail the build instead of panicking when a plugin answer string cannot be converted - #38046 bun build --server-components: require the bun target and reject directives without a framework *(crash fix only)* - #38095 js_parser: fix panic on decorated declare/abstract fields in class expressions with experimentalDecorators - #38966 bundler: keep deep CSS, export star and composes graphs from overflowing the linker's stack - #38984 bundler: stop an export star ambiguity that loops back into a re-export chain from overflowing the stack - #39113 css: reject stylesheets of 2 GiB or more instead of aborting on an int cast - #39396 bundler: frame .jsc bytecode sidecars and verify them before decoding - #39855 bundler: join the work still on the pools before the bundle is torn down *(crash fix only)* - #41157 dev server: leave out an html link to a cached json module instead of panicking, and mark a new placeholder file stale - #41801 css: decode ill-formed UTF-8 to U+FFFD before tokenizing *(crash fix only)* - #41827 bundler: handle YAML and JSON5 keys that are not strings instead of panicking - #42242 js_parser: compress symbol link chains when following merged declarations - #42387 bundler: check receivers on the Bun.build plugin object and freeze its filters during a build - #42413 Bounds-check the InternalSourceMap window reader - #42657 macros: keep visited values alive so a reused address does not get another value's Expr - #43330 transpiler: do not print an empty `var` for a data file with no named export - #43355 bundler: fix "The memory limit has been exceeded." on large HTML entries - #43658 react-compiler: fix skipped functions and build aborts for dead code in a try body *(crash fix only)* - #44137 js_parser: fix four crashes of exports.eliminate and exports.replace - #44467 js_parser: replace skipped expressions with E::Missing and skip argument checks after a stack overflow - #44662 js_parser: walk binary chains on the heap and check the stack when rewriting decorated #private accesses - #44712 json5: reject sources of 2 GiB or more before parsing instead of aborting on an int cast - #44864 js_parser: walk conditional chains in import()/require() and define keys in a loop - #44883 js_parser: reject a decorator on a class static block, keep decorators out of the body of `declare global` *(crash fix only)* - #45045 Fix a segfault in new Bun.Transpiler(): re-point options.log after the constructor moves its Log - #45604 css: keep a url() in an at-rule prelude as written, and never print the resolved path of a url() *(crash fix only)* - #45748 bundler: put --banner/--footer in the bytecode ESM module record (flags from a parse, entries from JSC) *(crash fix only)* - #45960 macros: give each parse-worker macro VM its own env loader - #45969 js_parser: copy object and array defines per use, and copy the list of a lone JSX spread object *(crash fix only)* **`bun build --compile` and standalone executables** (3) - #31787 Don't crash at startup when a standalone executable's embedded graph is corrupted *(crash fix only)* - #38251 compile: exit with an error instead of SIGBUS when a standalone executable is truncated - #41360 standalone: check every offset in the embedded module graph before reading it **Resolver, module loading, plugins, paths** (25) - #32269 Bun.plugin: validate the namespace without a shared regex - #33183 bun:jsc: filter internal cells out of getProtectedObjects() - #34575 Don't register native functions as their own constructors - #36340 paths: size the thread-local join output buffers to MAX_PATH_BYTES on Windows - #37037 mock.module: reject async factory results that are not objects - #37065 bun:jsc: propagate JSONParse exceptions from samplingProfilerStackTraces - #37529 resolver: don't abort on a package.json sideEffects entry longer than the join buffer - #38179 node:module: throw instead of crashing when module._compile is set to a non-function - #38273 bun test: report a test file or preload the loader cannot resolve instead of exiting; keep the JUnit report valid U… *(crash fix only)* - #38732 paths: compute the common path of 9+ inputs with the same loop as fewer *(crash fix only)* - #39228 paths: strip C:\\ down to the drive root in without_trailing_slash_windows_path *(crash fix only)* - #39650 bun run --filter: stop panicking on workspace paths longer than the path buffer - #40186 resolver: stop deeply nested exports targets from overflowing the stack - #40258 resolver: publish Entry.abs_path through the per-entry mutex - #42183 node:module: reject a _resolveFilename override result that contains a null byte - #42401 node:module: accept any `this` in Module.prototype.require *(crash fix only)* - #42405 Bun.plugin: transpile a copy of typed array onLoad contents - #42414 node:module: end the Module._stat path at the first null byte - #42685 resolver: strip the trailing separator inside bust_dir_cache - #42735 Throw a RangeError instead of aborting when require.resolve paths or Worker preload outgrows its Vector - #43067 Report a path that does not fit a path buffer instead of aborting *(crash fix only)* - #44410 Fix a crash when code from a node:vm context reads require.cache or require.extensions - #44466 Trace the value an object or data module exports from its JSSourceCode - #45044 Bun.plugin: give onLoad's args.path its own bytes - #45117 cjs: do not call an `__esModule` getter during the annotation lookup **Dev server, `bun bake`, routers, `--watch` and `--hot`** (28) - #28793 Stop file watcher thread before Global.exit tears down memory *(crash fix only)* - #32143 bake: fix "Runtime file not found" panic in production builds of custom frameworks - #32443 watcher: don't free the Watcher in the spawn-to-start window *(crash fix only)* - #33232 bake: normalize the HTTP request-target before matching framework routes - #36812 bake: respond 500 and release both RequestContext refs when on_plugins_rejected / OOM drains a deferred framework r… - #37039 bake: report per-file print failures in the dev server instead of serving empty modules - #37276 hot_reloader: take entries_mutex for watcher-thread directory cache probes - #37444 bake: unregister Bake::SourceProvider from the source map table when it is destroyed - #39290 FileSystemRouter: match / against a root-level optional catch-all route *(crash fix only)* - #39291 FileSystemRouter: order dynamic routes by per-segment precedence like Next.js *(crash fix only)* - #39629 watch: report a failed watcher init as an error instead of a crash - #41185 bake: check for exceptions in the production build's module loader hooks and helpers - #41340 bake: skip the directory watch when the directory cannot be opened - #41617 Decide a directory watch event from the watchlist, not from the resolver's cached listing *(crash fix only)* - #42547 bake: re-arm the memory visualizer timer when it fires - #42733 dev server: make a client script request wait for the bundle in flight - #42828 bake: serve routes from a router root outside the project root instead of aborting or answering 404 - #42831 bake: resolve app.root and router roots through one checked join - #42836 bake: report route scan errors instead of aborting, and fail bun build --app on them *(crash fix only)* - #42840 dev server: map a router type's server entry point to the root route of that type - #42862 Bun.serve: return before a pending app.plugins setup() settles *(crash fix only)* - #42920 Do not create a mimalloc heap per FileSystemRouter, reload() or :nth-child(An-B) selector - #42934 dev server: register a client component without evaluating it - #43329 dev server: check the route bundle index of a client script URL before Index::init - #44249 fs.watch: read each directory and close it before descending - #44344 Windows: fix a watcher panic and lost events in a burst of file changes, and a --hot that stops watching a deleted… - #44744 dev server: answer a cached-file lookup only for a graph that bundled the file - #44746 dev server: keep an importer in its own graph when an import fails or is deleted **`Bun.serve`, sockets, HTTP, WebSocket, HTTP/2, QUIC, DNS** (28) - #42667 Reland "usockets(windows): keep a closed poll alive until the outer tick and libuv are done with it" (#39643) - #33015 fix(windows): segfault in uv__wake_all_loops after system resume *(crash fix only)* - #35761 node:quic: detach lsquic ctx pointers before the finalize-order sweep at worker VM teardown - #37082 Bun.serve: terminate FIFO/pipe file responses at EOF - #38024 dns: keep the c-ares uv_poll_t alive while its poll callback is on the stack (Windows) - #38636 serve: fix route use-after-free after reload() with tls.serverName *(crash fix only)* - #40888 server.fetch: copy a Headers argument instead of adopting the wrapper's pointer - #41337 Update lsquic to 4.9.4 and free unsent stateless resets on destroy *(crash fix only)* - #41384 usockets: hold a tick level for the whole of close_all - #41412 Windows: wait for close completions when closing a worker's uv loop - #41516 node:http2: handle an empty byte range in respondWithFile and respondWithFD - #41521 udp: report every binaryType from the getter, reject a dgram bind of the other family *(crash fix only)* - #42188 net: do not assert a two-character host in SocketAddress.parse - #42210 libuv(windows): keep a pipe's completed read counted until its read callback returns - #42334 fetch, Bun.serve: throw a RangeError for Headers that total 4 GiB or more *(crash fix only)* - #43738 usockets: close a socket whose resume the kernel refuses from the loop, not from the caller - #44338 node:http: response trailers travel with the end call of the response *(crash fix only)* - #44433 bake: make the parked-request list non-owning and look up the DevServer when a plugin load settles - #44533 node:quic: capture the handshake while the conn is alive, set the application at session creation - #44734 Bun.serve: answer HEAD for an S3-backed Blob body without an S3 stat - #44751 node:quic: close() waits only for opened streams, and lsquic sends no GOAWAY before HTTP/3 starts *(crash fix only)* - #44897 node:http2: throw instead of panic when the native setNextStreamID() misses its argument - #45076 node:http2: let close() and destroy() win over the refusal of a request - #45341 uws: AsyncSocket::write takes a size_t length, so res.end() sends a body of 2 GiB or more whole - #45522 node:http2: throw for an ALTSVC frame that is too long and for a pushPromise id that is not a stream id - #45676 node:quic: do not reset a stream lsquic has already finished - #45822 node:quic: name a stream in queued session events by a per-session key, not by its address - #45858 Bun.serve WebSocket: a message that does not fit in memory fails one connection, not the server *(crash fix only)* **Streams, Blob, S3, files, `node:fs`** (28) - #33845 io: propagate IoRequestLoop init failure instead of aborting *(crash fix only)* - #36365 prompt: drop debug_assert that rejects answers containing CR - #37090 Deliver FIFO bodies whose writer connects after the reader opens *(crash fix only)* - #38039 node:fs: stop fs.copyFile(src, "") from segfaulting on Windows - #38653 shell(cp): reject copying a directory into itself; walk cp trees without recursion - #39207 Convert scope-object receivers in the chaining functions and inspect.custom fallbacks - #39390 Blob deserialize: reject over-long paths, treat size >= MAX_SIZE as unknown, make slice() non-panicking - #39639 fetch: drop the upload and drain hop refs at VM teardown *(crash fix only)* - #40008 inspect hooks: copy user options with putDirectMayBeIndex *(crash fix only)* - #40462 Windows: FileSink.start({ path }) on a live writer: hand the writer a libuv fd and close the old source *(crash fix only)* - #41440 node:fs: pass the buffer to the read/readv/write/writev callback on error - #41584 Walk the timer pairing heap without recursion - #41608 native-readable: accept a stream with no native handle - #41710 JSSink write(): convert the chunk before resolving the native sink *(crash fix only)* - #42711 webstreams: bound the native recursion through a chain of tees or text streams - #43264 fetch: reject a file: URL whose path has an encoded NUL - #43709 s3: fix double free of a multipart part's bytes on worker terminate - #43950 streams: link readers and writers last, reject their promises as handled - #44036 PipeReader: label a chunk Eof only when the reader is at its end - #44181 streams: throw instead of aborting when a direct stream's text sink cannot take a string chunk - #44195 fs: validate POSIX directory records in one parser, report a malformed record as EIO *(crash fix only)* - #44269 streams: join the string chunks of a text consumer with one allocation - #44490 watch(windows): report a failed child spawn as an error instead of a panic *(crash fix only)* - #44954 process.stdout/stderr with no FileSink: write synchronously, reset after a failed write *(crash fix only)* - #45004 streams: leave a stream alone when a consumer fails to lock it - #45521 FileSink: throw ERR_ILLEGAL_CONSTRUCTOR from the constructor that script reaches by writer.constructor - #45738 s3: own the Blob store across the calls that run user JS - #45975 node:stream: do not touch the web controller after the web side is done **Node-API, V8 API, `bun:ffi`, `process.dlopen`** (15) - #36609 napi: implement uv_cwd on POSIX - #37989 bun:ffi: stop cc() from turning non-numeric pointer arguments into garbage pointers - #38057 bun:ffi: make cc() reject non-numeric i64/u64 arguments instead of passing garbage - #38425 bun:ffi: throw on an empty cc() source array instead of panicking - #39652 napi: implement uv_async_t, uv_queue_work and uv_default_loop on posix - #39805 Share one handle scope implementation between Node-API and the V8 API - #39892 napi: implement uv_idle_t, uv_prepare_t, uv_check_t and uv_timer_t on posix - #40144 bun:ffi: return undefined for a NULL napi_value from cc() and throw the scheduled napi exception - #40773 bun:ffi: add the full byteOffset in read.*, do not truncate it to int32 - #41704 napi: hand the thrown value to napi_get_and_clear_last_exception after napi_run_script - #42960 process.dlopen: run a V8 addon's init function after dlopen() returns - #43797 Fix debug assertion on an empty error message from a V8 addon or SQLite *(crash fix only)* - #43802 bun:ffi: throw a TypeError when a cc() symbol is called after its library's close() - #43940 napi: fail with ERR_BUFFER_TOO_LARGE instead of aborting above the ArrayBuffer limit *(crash fix only)* - #44921 bun:ffi: pad a short call to a cc() symbol with undefined **`node:vm`, workers, process, timers** (19) - #34623 node:vm: run DONT_CONTEXTIFY contexts directly against the real global - #32839 node:vm: reject invalid cachedData instead of crashing - #36921 error printer: clear the pending exception when formatting a non-Error uncaught value throws - #37270 error printer: one render per error, [Circular] under the key that closes the cycle - #38740 bun:test: give each VM its own fake clock *(crash fix only)* - #39864 Report a refused HTTP, bundle, IO or process waiter thread as an error instead of a crash *(crash fix only)* - #39992 process: deliver exceptions reported against a node:vm context to uncaughtException - #41654 node:vm: give each SourceTextModule request the import attributes of the declaration that created it *(crash fix only)* - #41739 Do not forward the inherited IPC channel to spawned scripts and tools - #41769 node:vm: stop compiling accepted cachedData, report each cachedData decode to the GC *(crash fix only)* - #42045 bun:test fake timers: never move the fake clock backwards - #42308 process.execve: throw instead of aborting for a string past the string limits - #42734 node:vm: report cachedData of 2 GiB or more as rejected instead of aborting - #42843 process.dlopen: reject a filename of PATH_MAX or more before dlopen() - #43500 process: accept SIGSTKFLT, SIGPOLL and SIGPWR, and emit every name of a signal number *(crash fix only)* - #44486 worker: stop the start sequence when a handler it calls stops the worker - #44771 timers: allocate ids from one 64-bit counter that never wraps - #44837 --hot: defer a reload during the preloads, and report a reload that cannot start - #44991 Fix a use-after-free in the VM ref-string intern for a string over the length limit **Shell, spawn, CLI, `bun test`, `bun install`** (31) - #30642 Fail fast at startup when simdutf has no usable implementation for this CPU - #34223 Fix four crashes: HTMLRewriter disturbed body, S3 locked-stream upload, ConnectionsList closed parser, shell brace… *(crash fix only)* - #34884 Guard the console and test-runner formatters against native stack overflow on deeply nested values *(crash fix only)* - #36584 process.chdir: publish an immutable cwd slice so no thread sees a torn cwd - #37135 bun test --parallel: hold the JSC API lock while draining the worker's final IPC backlog - #37527 shell(mv): report ENAMETOOLONG instead of panicking when a source name does not fit the path buffers - #37528 cli: stop aborting on absolute script paths longer than 1024 bytes on Windows - #38162 shell(cp): report ENAMETOOLONG instead of panicking on operands longer than the path buffers - #38205 shell(windows): report ENAMETOOLONG for operands that do not fit the path buffer - #39010 bun test: exit through the VM teardown path when --bail stops a run - #39104 bun test: report over-long coverage dir, JUnit outfile and bunfig root instead of panicking *(crash fix only)* - #39638 shell(cat): serve a second cat on the same stdin instead of hanging or panicking - #39641 usockets: report an out-of-descriptors event loop init as an error, not a crash *(crash fix only)* - #40181 shell: stop deeply nested if clauses from overflowing the parser stack - #40885 shell: throw instead of panicking when a ReadableStream is used as a redirect - #41155 ipc: send a queue item larger than 2 GiB in capped write requests - #42298 bun:test: print String objects with 16-bit storage correctly - #42577 bun:test: root the return values toHaveReturnedWith collects - #43606 shell(windows): report a failed pipe reader start through on_reader_error instead of leaking the subprocess *(crash fix only)* - #43838 node:cluster: read a worker's `ack` and `addressType` in the primary only when they are int32 - #44172 node:cluster: refuse a descriptor of the wrong kind in the primary *(crash fix only)* - #44185 node:cluster: one handle for each descriptor that workers name *(crash fix only)* - #44491 bun test: run every callback when native code leaves an exception pending *(crash fix only)* - #44694 shell mv: refuse to copy a directory into itself on the cross-device fallback - #44752 shell: take the command-substitution capture and drop its NUL bytes - #44981 shell: reject NUL bytes in .cwd() and .env() at the native setters - #45206 ini: reject a source of 2 GiB or more in Parser::parse instead of aborting on an int cast *(crash fix only)* - #45348 bun test: fix a segfault in .not.toThrow(Class) when Symbol.hasInstance accepts a thrown string, symbol or BigInt - #45649 shell: replace the output counters in mkdir, cp, ls and touch with the OutputTask queue - #45792 bun test: SIGKILL a spawnSync child that is still running 500 ms after the test's timeout *(crash fix only)* - #45910 create: own the remote-template response buffers instead of parking them in the CLI arena **Web APIs, Buffer, encoding, URL, crypto, zlib, SQLite, Redis and the rest** (96) - #29709 console: guard JSX/Proxy recursion in Bun.inspect (stack overflow SIGSEGV) - #30817 console.takeHeapSnapshot: clear prior snapshots before building - #30956 spawnSync: make signal-forwarding register/unregister safe for concurrent callers *(crash fix only)* - #31505 node:zlib: reject invalid brotli flush values at validation *(crash fix only)* - #31735 node:path: fix win32 drive-relative resolve on non-Windows hosts *(crash fix only)* - #32085 Fix crash when RedisClient onclose/onconnect is set to a non-callable - #32240 Fix BroadcastChannel custom inspect crash with numeric option keys - #33181 Reject interior null bytes in Bun.mmap, Glob.scan, and FileSystemRouter paths *(crash fix only)* - #33752 node:crypto: validate EC JWK private scalar matches public point in createPrivateKey - #34976 spyOn: install and restore through one writer that throws when the object refuses *(crash fix only)* - #35562 structuredClone: purify NaN in deserialized Date timestamp so getTime never returns a forged JSValue - #35618 napi(windows): load addons that import node.exe without win_delay_load_hook - #35757 Coerce later arguments before capturing input buffers in Bun.Transpiler and Bun.RedisClient - #37252 Report UTF-16 to UTF-8 encode counts through size_t so exactly 2^32 written bytes doesn't wrap to 0 - #37338 node:module: build require.cache without user-writable globals and propagate its exceptions *(crash fix only)* - #37340 redis: accept unsubscribe acks that arrive outside subscriber mode - #37370 Error.appendStackTrace: make appending an error's trace to itself a no-op - #37443 node:crypto: fix null deref when worker.terminate() lands during an EC JWK private key import - #37448 jsc: check for exceptions before using a stored constructEmptyArray result *(crash fix only)* - #38009 MessagePort: fix a heap-use-after-free in contextDestroyed(), release ref() when the last 'message' listener is rem… *(crash fix only)* - #38469 napi: settle or refuse async work queued during VM teardown instead of taking a ticket - #38708 Handle 16-bit module sources in the error preview, the new-position fix-up and the REPL *(crash fix only)* - #38821 process.env: make a failed env build throw instead of aborting (Windows 0xC0000409 on Bun.$ / Bun.sql / process.env… - #38871 process.env: coerce to string on every execution of an assignment, not just the first - #38877 cli: exit 128 + signo when bun cannot die from a re-raised signal (bun as container PID 1) - #38926 Clear the inherited signal mask at startup and exec children with an empty one *(crash fix only)* - #39382 Make a failed util.inspect load throw from custom inspect functions instead of aborting - #39481 Always create the error when a native error message exceeds the string length limit - #39651 performance: keep the user timing entry counts exact after clearMarks(name) and clearMeasures(name) - #39775 Turn seccomp SIGSYS traps into ENOSYS so the syscall fallbacks run on Android - #39968 process.dlopen: replay a non-context-aware V8 addon only while no other live VM owns it - #39975 watch: report a failed reload exec as an error instead of a panic *(crash fix only)* - #40346 Give Glob's native scan methods their own private names - #40554 node:crypto: copy password and salt for async pbkdf2 and scrypt - #40567 url: reject URL-encoded input over the WTF decode limit instead of aborting - #40577 url: throw a RangeError instead of aborting when URLSearchParams or FormData outgrows its Vector - #41073 Store array-index property names as indexed properties in native object builders - #41137 Write the sampling profiler report at exit from Bun, not JSC's atexit hook - #41365 webview: fail only the view when WebKit lacks initWithDirectory: - #41574 Decode a private copy of a JS buffer in the UTF-8 decoders *(crash fix only)* - #41652 console: read a BigInt depth option by value in console.dir - #41749 Startup: reopen fd 0-2 as /dev/null only when the fd is closed - #41819 Report an incoherent BUN_JSC_* option combination as a configuration error, not a crash *(crash fix only)* - #42158 webview: reject malformed Chrome replies instead of crashing - #42179 shell: clamp a `> ${buf}` redirect to the target buffer's live length - #42187 node:crypto: throw ERR_OUT_OF_RANGE for >2 GiB buffer arguments instead of aborting - #42191 URLPattern: throw instead of aborting when a pattern string passes the string limit - #42192 Copy WebAssembly.Memory bytes for native borrows that outlive the call *(crash fix only)* - #42198 Make Bun.$, Bun.sql, Bun.postgres and Bun.SQL custom value getters so reifying the Bun object passes exception chec… - #42203 node:fs: fs.read into a WebAssembly.Memory view writes into the block a grow freed - #42214 Headers: throw a RangeError instead of aborting when the set-cookie list cannot grow - #42218 Headers: throw instead of aborting when a value passes the string length limit - #42220 URLPattern: throw instead of aborting when the token list cannot grow - #42225 Throw ERR_STRING_TOO_LONG from Bun.wrapAnsi instead of aborting when the output passes the string length limit - #42226 Throw instead of aborting when a MIME string does not fit in a string *(crash fix only)* - #42237 Bun.Cookie: throw instead of aborting when the Set-Cookie string passes the string length limit - #42249 Copy a shared input before libdeflate compresses it in Bun.gzipSync and Bun.deflateSync - #42253 bun test: walk nested describe scopes without native recursion - #42259 Throw instead of aborting when a domainToASCII host passes the string length limit - #42310 Parse a private copy of a shared or resizable buffer in Bun.Transpiler, Bun.markdown, Bun.YAML and Bun.TOML *(crash fix only)* - #42312 YAML, JSON5, XML stringify: throw instead of aborting when the output passes the string length limit - #42318 Bound libdeflate's emit path so a racing input cannot overrun the output - #42338 inspector: check the type of process.argv in getModuleGraph - #42364 node:perf_hooks: do not truncate the monitorEventLoopDelay resolution to int32 - #42412 transpiler cache: reject an entry with no sourcemap section - #42479 worker_threads: do not abort when markAsUntransferable/markAsUncloneable gets a WebAssembly GC reference - #42517 EventTarget: skip a listener object that has no realm - #42518 fs.Stats: make the date accessors define the property like Object.defineProperty *(crash fix only)* - #42575 Stop natives from writing onto a foreign `this` with putDirect: process.ppid, require.cache, StringDecoder, the nat… *(crash fix only)* - #42631 JSStringView: pin the cell that owns the borrowed characters - #42660 bun_core: read /dev/urandom when getrandom(2) answers ENOSYS or EPERM - #42780 node:crypto: treat a name too long to convert to UTF-8 as unknown instead of aborting - #42782 node:crypto: throw ERR_OUT_OF_RANGE for a passphrase larger than INT_MAX bytes - #42856 url: do not abort when a host is too long for the IDNA conversion buffers - #42868 sqlite, console, process: do not abort on a string too long to convert to UTF-8 *(crash fix only)* - #42941 Bun.sliceAnsi: throw instead of aborting when the result passes the string length limit - #43058 Bun.serve: fix crash and cross-request 500 when inspecting a non-Response return value throws - #43904 JSC bindings: build property keys from a BunString through Bun::toIdentifier - #44124 Bun.Image: decode WebP into a Bun-owned canvas and read ICCP without the demuxer *(crash fix only)* - #44190 Convert scope-object receivers before Buffer read*/write* and vm.Script describe them - #44211 Stop getsockname(out), useFakeTimers() and the stream source pull() from writing onto a caller's object with putDirect - #44295 bun test --coverage: append a final newline to a text that lacks one *(crash fix only)* - #44360 rust-argon2: return OutOfMemory instead of aborting when the memory cost cannot be allocated - #44421 node:zlib: free zstd's workers before the dictionary they read - #44521 util.parseArgs: pick the default args start from a per-VM eval flag, as Node v26 does *(crash fix only)* - #44740 structured clone: tolerate a zero-sized shared WebAssembly.Memory in computeMemoryCost() - #44759 HTMLRewriter: park a suspended handler's token before the output flush - #44907 Builtins section format 2: an engine stamp says which buns compile its modules - #45188 Reject an oversized WebCrypto cipher output instead of aborting - #45354 Throw for a `file:` URL whose path is not UTF-8 on Linux and macOS, through one `fileSystemPath()` accessor *(crash fix only)* - #45608 ipc: refuse an over-long message before the receive buffer stores it - #45624 webcrypto: write the key type into the X25519 structured-clone record - #45625 node:sqlite: refuse session.close() and Symbol.dispose inside a SQLite callback - #45653 glob: a group with `?` or a class matches when an alternative takes 64 bytes or more - #45820 Bun.file, S3Client.file and Bun.write no longer keep a buffer path alive forever - #45832 `bun check`: fix a panic on `export *` without a module specifier, and a false error for one in parentheses ### Already fixed on `main`, or duplicates of a pull request above Already fixed: #27323 #30401 #31011 #31206 #31566 #31626 #31695 #31702 #31945 #32773 #34154 #34697 #34744 #34964 #35655 #35816 #36020 #36181 #36296 #36342 #36581 #36602 #36807 #36818 #36857 #37172 #37235 #37239 #37267 #37420 #37731 #37914 #38113 #38119 #38509 #38514 #38540 #38975 #39410 #40749 #41163 #41171 #42108 #43085 #43230 Duplicates: #45654 #29986 #33378 #36895 #37070 #37639 #38014 #39021 #41266 #42250 #42951 #43238 #44259 #45335 #45565 #45726 #45965 Fixes #5019 Fixes #6106 Fixes #10690 Fixes #10886 Fixes #13566 Fixes #14745 Fixes #15551 Fixes #20454 Fixes #21310 Fixes #29145 Fixes #30454 Fixes #30613 Fixes #30766 Fixes #32103 Fixes #32142 Fixes #32183 Fixes #32212 Fixes #39060 Fixes #42296 Fixes #42931 Fixes #43671 Fixes #44201 Fixes #44735 Fixes #44783 Fixes #45198 Fixes #45327 Fixes #45491 Fixes #45721 --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
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### What does this PR do? Consolidates the open pull requests on the CSS parser (`src/css`: parsing, minifying, lowering, printing, CSS modules) into one. 179 open pull requests were in scope. Each was judged by one rule: **the output must mean to a browser what the input meant.** Every claim was run through a build of `main`, a build with the change, lightningcss 1.33 and Chromium 156 (CSSOM, computed values, painted pixels for colors and gradients), and counted against 10,116 real stylesheets: the published CSS of about 190 popular npm packages, plus stylesheets from open source repositories. 107 land here, whole or in part, most of them cut down. The source diff is net negative. Of the 10,116, 9,509 are stylesheets that someone ships. The rest are test fixtures of other tools (521), Tailwind v4 source that needs its plugin (59) and SCSS, PostCSS or template source (27). | 9,509 shipped stylesheets | `main` | this branch | |---|---|---| | fail to build | 71 | 35 | | ... of those, valid CSS that Bun rejects | | 0 | | minified output reads differently in Chromium than the input | 552 | 2 | | CSS modules with a name that is referenced but not defined, or exported but not defined | 166 | 0 | | all 10,116 | `main` | this branch | |---|---|---| | fail to build | 192 | 141 | | minified output reads differently in Chromium than the input | 593 | 15 | | build on `main`, fail here | | 0 | | right on `main`, wrong here (minified, and at the default targets) | | 0 | | size of the minified output, no targets | 162.32 MB | 162.47 MB (+0.093%) | | size of the output at the default targets | 224.1 MB | 210.2 MB (-6.2%) | A syntax error is a build error, with one exception: the IE star hack `*zoom: 1` is skipped, because tachyons and handsontable ship it. The 35 shipped stylesheets that fail are invalid CSS: 28 have a selector that Chromium drops (semantic-ui-css, swiper, @ionic/core, Adobe Spectrum, xp.css), 2 an `@import` after other rules, and one each `@supports not X and Y`, a nested `@keyframes`, a stray comma, a selector list in `::slotted()`, `@media screen\0` (govuk-frontend). The 2 that read differently fold a `color-mix()` inside a gradient (see the known gaps). The growth of the minified output is rules and declarations that `main` deleted by mistake: 87 KB of rules, 45 KB of prefixed declarations that only browser targets can rule out. #### Popular CSS that `main` breaks today - normalize.css, modern-normalize, sanitize.css: `font-family: monospace, monospace` is collapsed to `monospace`, which changes the font size from 16px to 13px (#46662). - CKEditor 5, Tabler, Carbon, VitePress, Ionic, PatternFly, Excalidraw: a rule of custom properties is deleted as a "duplicate" of a later rule with the same selector and other custom properties. 37 stylesheets lose 1,681 custom properties (#33684). - Material Components, daisyUI, DocSearch, plyr: a `var()` size loses to its own fallback (#42101). - nextra, daisyUI, CKEditor: declarations written after a nested rule are moved above it (#45462). - antd 4, purecss, govuk-frontend: browser hacks in selector lists start to apply everywhere (#42100). - foundation-sites, flatpickr, 98.css, blueprintjs, scalar, react-datepicker: the build fails on valid CSS (#46756, #38552, #38534). tachyons, handsontable: it fails on the IE star hack (#46751). - nodejs.org, Mantine: a CSS module exports classes that no rule defines, because the `@apply` or `@mixin` in them is moved out of the rule (#46759). - hint.css and 42 more: `z-index: 1000001` and `1000000` become the same number (#46715). - Adobe Spectrum: `--version: 5.0.1` prints as `5.1`. - A quarter of all stylesheets: minified output has a stray space in `align-items: center` (#41993). #### Behavior changes to look at first 1. **`light-dark()` is kept as written at the default browser targets** (#42009). The lowered form `var(--buncss-light, a) var(--buncss-dark, b)` is invalid unless a compiled `color-scheme` covers the element: 184 of the 215 real stylesheets that get it never define the variable, so every browser drops the declaration. The docs section on the polyfill is removed. 2. **`border` is not built from longhands** (#42072): `border-width:0;border-style:solid;border-color:red` stays three declarations, because `border` also resets `border-image`. 305 real stylesheets grow by 30 KB in total; `bootstrap.min.css` by 113 bytes, 5 gzipped. No real stylesheet was found where the old merge shows, so this is the one to drop if size matters more. 14 existing expectations change. 3. **A CSS module no longer exports names that only occur inside `:global(...)`** (#45487). 73 real modules lose 202 export keys, all of them names that no rule has. `import { g }` or `composes: g` of such a name becomes a build error. 4. **Container names and `@counter-style` names stay global in a CSS module** (#45247 by @mikamikasuki). `main` hashes the `@container` name but not `container-name`, so a named query never matches. postcss-modules (Vite, css-loader, Next.js) keeps them global; lightningcss and esbuild hash both. Global keeps a container that is queried from another file or from JS working. 5. **Syntax errors are build errors, also two that `main` lets through**: a media query that stops short (`@media screen and {`, `@media not {`, `@import "a.css" screen and;`) and `@media (width <) foo {`. No stylesheet of the 10,116 has either. A condition that is valid by the grammar though no browser knows it, `( ... )` or `fn( ... )`, is kept as written (#46756): `(min-width:0\0)`, `(not(hover))`. 6. **Declarations after a nested rule stay where they were written**, as a nested declarations rule (#45462). Changes the output of 199 real stylesheets; in a fuzz of 2,850 nested programs compared by computed style, `main` was wrong in 1,056 and the pull request's code, before it was trimmed here, in none. 7. **`Bun.color`**: `color()` inputs are converted instead of returned as a string (`Bun.color("color(srgb 1 0 0)", "hex")` was `"color(srgb 1 0 0)"`); `currentColor`, system colors and `light-dark()` give `null` in the converting formats instead of the keyword as a string; a relative color or `color-mix()` outside sRGB is clipped, not gamut-mapped (`hsl(from oklch(100% .399 336.3) h s l)` is `#ff5bff`, was `#fff`). 8. The `:-moz-any()` and `:-webkit-any()` copies of rules with `:is()` are gone at the default targets (#45945, #42029). The `:-webkit-any()` copy outranked the original rule: `.title{color:blue} :is(h1,h2,h3){color:red}` painted red. 5.8% of all default-target output was the `:-moz-any()` copies. 9. `Property` grows from 216 to 224 bytes: `Url` stores its text as a slice so that two `url()` values can be compared (#46895). The pull request packed a pointer and a `u32` behind `unsafe` to avoid that. #### Not in this PR, needs a decision - **Raise the default browser targets (#40369) and add a `cssTarget` option (#40368).** Today: Chrome 80, Edge 80, Firefox 78, Safari 14, Opera 67, and no public way to change them. At Vite 8's floor the output of the 9,924 stylesheets is 15.3% smaller (3.9% gzipped). About a dozen fixes here only matter at today's floor, and code for older targets is unreachable without the option. - Vendor prefixes for `user-select`, `appearance`, `hyphens` and five more (#45814): 1,116 real stylesheets lack a prefix they need at the default targets. And for `backdrop-filter` (#44648): 173. - Clip instead of gamut-map in the sRGB fallback of a plain wide-gamut color: deletes about 90 lines, changes every pinned fallback hex. If the mapping stays, #44647 by @oddharsh makes it closer to what browsers paint (colors off by 2/255 or more: 168 to 110 of 3,170 real ones). #### Changes **Rules: duplicates, merging, nesting, fallbacks** - The `:-moz-any()` copy of every rule with `:is()` or `:not(a, b)` is gone: Firefox 78 has `:is()` (#45945). 1,164 real stylesheets - Keep declarations written after a nested rule in place with a nested declarations rule (#45462). 379 real stylesheets - With nesting compiled away, an unknown at-rule inside a style rule was moved out of it: `.wrapper{@apply flex}` printed a bare `@apply flex;` and the rule was gone, so a CSS module exported a class that no rule defines. It now stays in a block under the compiled selector. 72 real modules with Tailwind's `@apply`, 25 with Mantine's `@mixin` (#46759). 316 real stylesheets - Keep !important in the rules generated for logical properties and color-scheme (#38597). 311 real stylesheets - With browser targets, remove an earlier duplicate rule only when its declaration block is equal (#46861). 171 real stylesheets - Compare custom property names in `PropertyId` equality and importance in duplicate-rule detection (#33684). 40 real stylesheets - Keep same-condition @supports rules and empty named @layer blocks (#46733). 31 real stylesheets - Keep target-added vendor prefix passes on cloned and re-minified rules, and never print a bare `:full-screen` (#43339). 12 real stylesheets - Keep the selectors on rules added for color fallbacks and logical properties (#43240). 3 real stylesheets - A later declaration of a property drops the `@supports` color copies of the earlier one, which printed after the rule and won (#45560). 2 real stylesheets - Do not merge style rules in a stylesheet that holds `revert-rule` (#46953). 1 real stylesheets - `@import ... supports(-webkit-mask: none)` kept its prefix (#38589) **Properties and shorthands** - Print align-items:center without a stray space when no safe/unsafe keyword is given (#41993). 3,317 real stylesheets - Emit the physical longhands instead of the inset shorthand for targets without it (#38583). 1,452 real stylesheets - Keep the stops of an upward gradient as written, and drop a `50%` hint only at the midpoint (#46790). 104 real stylesheets - Emit unparsed border-block-* declarations when compiling logical borders (#38582). 89 real stylesheets - Keep repeated font families and dedupe only the inserted system-ui fallbacks (#46662). 88 real stylesheets - A `width` / `height` / `min-*` / `max-*` with `var()` or `env()` was printed before the plain fallback written above it, so the fallback won (#42101). 26 real stylesheets - Keep box-orient and box-direction when flex-direction or flex-flow follows (#45672). 16 real stylesheets - Write held prefixed background declarations at every flush (#46882). 6 real stylesheets - Derive equality for Size2D and BorderRadius, and keep every prefix in the border-radius handler (#45665). 2 real stylesheets - Print `none` instead of an empty border-image, mask-border or mask-box-image value (#45143). 2 real stylesheets - Keep font/transition sub-properties on the side of the shorthand they were written on (#41990). 2 real stylesheets - CSS-wide keywords are not names: `font:12px Arial;font-family:inherit` printed `font:12px inherit`, `color-scheme:inherit` and `color-scheme:auto` printed `normal`, `transition-property:unset` was folded into `transition` (#42022). 2 real stylesheets - Only fold font longhands into `font` when the rule declared a `font` (#45459) - Keep a font family name quoted when its identifiers do not read back as the same name (#46606) - Stop rewriting valid positions into ones browsers reject (#45197) - `border` is no longer built from longhands unless the rule also sets what `border` resets (`border-image`), and an author's `border-image` reset is no longer dropped. `transition` is likewise only written where the rule wrote one, because it resets `transition-behavior` (#42072) - `border; border-image: <gradient>; border-image-slice: 1` lost the gradient in every default build (#42018) - A prefixed `linear-gradient` keeps its direction, written or generated: the prefixed syntax names the starting side and measures angles differently (#46697) **At-rules** - Print @font-face format() keywords as strings (#37979). 439 real stylesheets - Print @supports `not` conditions without a leading space (#38559). 88 real stylesheets - Reset after the number token of a unicode-range (#45835). 33 real stylesheets - Keep `<general-enclosed>` media and container conditions as written (#46756). 24 real stylesheets - A strict range such as `(width < 768px)` lowered for old targets still matched at exactly 768px. The step is now `.02px`. The `not all and` form for other units is not taken (#46806). 18 real stylesheets - Keep scanning an @supports condition after a nested block (#38552). 9 real stylesheets - Every `@counter-style name` printed as `@counter-stylename`, which browsers drop (also #46692). In a CSS module the name now stays global, like the `list-style` that refers to it (#33679). 9 real stylesheets - Keep a keyframe whose block has an invalid item (#46288). 2 real stylesheets - Read an @Property initial-value on the stylesheet's parser, keep an unmatched value as written (#45806). 2 real stylesheets - `@media {}` is `all`. A media query that stops after `and`, `or` or `not` (`@media screen and {`) is a build error; `main` printed `not all` or dropped the condition, silently. The `@layer` and type selector parts are not taken (#46869). 2 real stylesheets - Accept a name-only `@container` and a `style()` feature with no value (#46689). 1 real stylesheets - Parse `<timeline-range-name> <percentage>` keyframe selectors (#45652) - Allow `or` inside parentheses after a media type (#45088) - Print the `=` comparison in media and container queries as `=` (#45071) - Parse the @font-palette-values font-family descriptor as a list of family names (#45484) **Selectors** - Never wrap a selector list in :is() (#46787). 414 real stylesheets - Stop emitting :-webkit-any() copies of :is() that outrank the original rule (#42029). 373 real stylesheets - With browser targets, a selector list with a vendor-prefixed member was split, which revives hacks that rely on other engines dropping the whole list: `.s *::-ms-backdrop,.s{flex:auto}` applied everywhere. Rewritten; the list is printed as written (#42100). 42 real stylesheets - Print the vendor prefix on downleveled :any-link, :read-only, :read-write, :placeholder-shown and :autofill (#42131). 12 real stylesheets - Fix nesting lowering of a `&` that does not lead its selector (#43047). 8 real stylesheets - `@scope`: `&` and implicit selectors compile to `:where(:scope)`, relative selectors and bare declarations parse (#43165). 7 real stylesheets - Only reject bare :global / :local pseudo-classes in CSS modules (#38534). 5 real stylesheets - Stop truncating `@scope to (...)` and stop replacing `&` in the scope-end selector (#43146). 2 real stylesheets - `[xl|href$=".pdf"]` lost its namespace prefix (#45159). 2 real stylesheets - Match An+B keywords exactly and take only `+` as the leading sign (#42953). 1 real stylesheets - Parse ::details-content and ::picker() like ::part() (#45504). 1 real stylesheets - Parse :window-inactive as an ordinary pseudo-class, and accept it after ::selection (#45815) - Print :nth-col(1) and :nth-last-col(1) in functional form (#41575) - `li::before::marker` failed the build (#45810) - `&` inside `:nth-child(... of S)` is resolved when nesting is compiled away. The second selector serializer (326 lines) is deleted (#43024) **Colors and `Bun.color`** - Keep light-dark() as written under the default browser targets (#42009). 227 real stylesheets - Number and percentage channels parse in `lab()`, `lch()`, `oklab()`, `oklch()`, `hsl()` and `hwb()`; the hue of `lch` / `oklch` is no longer scaled by alpha (#45084). 130 real stylesheets - `Bun.color` returns `null` for `currentColor`, system colors and `light-dark()` in the converting formats, instead of the CSS keyword as a string (#33047). 130 real stylesheets - Relative colors: channel keywords are on the scale of their function (`rgb(from #369 calc(r + 10) g b)`), the origin's alpha is kept, a relative color kept as written gets no `@supports` copies, and a result outside sRGB is not folded (#45362). 31 real stylesheets - Keep rotate: 0deg out of none, and keep the origin alpha in relative colors (#38486). 13 real stylesheets - Compute the D50 reference white in f32 so greys convert to lab(l 0 0) like lightningcss (#38535). 7 real stylesheets - Return a missing hue for a grey from conversions into lch, oklch, hsl and hwb (#45201). 5 real stylesheets - Fix color(a98-rgb), srgb-linear relative colors and color-mix(in xyz-d50) (#38487). 4 real stylesheets - Match named colors without regard to ASCII case (#45092). 3 real stylesheets - Fold min(), max() and clamp() over plain numbers (#39515) - `calc(l - .08)` in a percentage channel of a relative color became NaN and printed `#000` (also #45970) (#45971) - Bun.color: convert color() inputs instead of returning them as a CSS string (#38488) - A `color-mix(in srgb, ...)` result outside sRGB prints `color(srgb ...)` instead of a gamut-mapped hex (#39269) **`calc()` and numbers** - Rounding to 6 significant digits ate into the integer part: `z-index:2147483647` became `2147480000`, `max-width:9999999px` became `10000000px`, `--x:1234567.5` became `1234570`. It now only cuts a fraction short: a value kept as tokens prints its source text, a typed value prints every integer digit and at least one digit of the fraction (#46715). 43 real stylesheets - A number without a unit is no longer repaired into `px` (`height:1.5715` is dropped by a standards-mode browser, so it prints as written), `calc(-1 * 0)` is not a length, and on a property of the range [0,∞] (sizes, border radii, padding, border and outline widths, gap, `flex-basis`, `font-size`) a `calc()` that folds below zero prints `0` instead of an invalid negative literal, and a negative literal no longer replaces the valid declaration before it (`width:10px;width:-5px` printed `width:-5px`) (#42104). 24 real stylesheets - Print numbers from the f32's shortest digits, not its f64 expansion (#38565). 17 real stylesheets - Print negative numbers below 1 with a single minus sign (#38516) - Keep math functions over two different length units as written (#38489) - Fold rem() with a truncated quotient, so it keeps the sign of the dividend (#32286) - A one-argument `min()` / `max()` around a sum printed without any function (`width:100% - 20px`) (#46145) - `round()` breaks ties upward and handles a negative step as browsers do (#45249) **CSS modules** - A CSS module exports its `@keyframes` names (`styles.spin`). Hashing is unchanged (#46720). 145 real stylesheets - A name inside `:global(...)` prints plain but was exported as `name_<hash>`, a class no rule has (also #38573) (#45487). 90 real stylesheets - Keep container names global in CSS modules (#45247). 6 real stylesheets - Tag the keyframes name when an `animation` value falls back to raw tokens (#46034). 6 real stylesheets - In a plain stylesheet `composes: a from "./b.css"` was treated as an import: the file was inlined and an absolute path printed (#45961). 4 real stylesheets - Drop a rejected composes instead of failing the file at print time (#38538). 1 real stylesheets - Keep every rule's custom properties for the composes conflict check (#38523) - Keep composes working after a nested rule in the same block (#38520) - `IdentOrRef::hash` read 2 of 16 bytes, so in release builds every class of a module hashed alike (#30784) **Tokens, `url()`, diagnostics** - The block skip stack no longer allocates on every block exit (#39533) - Report the diagnostic's line without its line breaks in position.lineText (#38342). 192 real stylesheets - Compare `url()` values by their text (#46895). 26 real stylesheets - Values kept as tokens keep the blanks they were written with instead of having them re-invented at print time: `attr(x type(<number>))` printed `type(< number> )`, which browsers drop. Minified output still drops the blanks that cannot matter (#45577). 19 real stylesheets - The IE star hack (`*zoom:1`) failed the whole build. The declaration is skipped, as every browser does. It is the one syntax error that builds: tachyons, handsontable and jasmine ship it (#46751). 8 real stylesheets - The path of a copied asset spliced into `url()` is always quoted, so a file name with a space or a parenthesis cannot end the `url()` (#41557). 7 real stylesheets - Move the skip loop of parse_until_before out of the generic body (#39520) - Remove dead code from bun_css: the unused `impl Default for Property` (#45618) - Default the at-rule and qualified-rule parser traits, drop the url_to_css shim (#31999) **Speed** Four inputs that took quadratic or exponential time, or produced output out of proportion, are now linear, with no new limit and no extra pass (#31639, #42243, #38531, #43421). **Tests only** - `css-fuzz.test.ts` never ran in CI and timed out on debug builds; it is a deterministic table now (#38500) - `nth-anplusb-ident.test.ts` counts heaps in a child process (#46331) - `color.test.ts` checks the ansi-16 sweep with one `expect()` (#42824) - Not CSS, but it failed this PR's CI and fails on `main` too: `ws-proxy.test.ts` on Windows, "a message sent during a TLS renegotiation arrives after it". The helper server now renegotiates from the callback of the frame's write (#46170) **No pull request covered these** - `--v: 5.0.1` printed as `5.1`, `--w: 1.0.0` as `10`, `--x: 1+2` as `12`, `2n+1` as `2n1`: a number token that touches another keeps its source text. - `color-scheme: auto` printed as `normal`, and `color-scheme: dark light` as `light dark`. - A bare `:global` or `:local` in a CSS module sets the scope of the names after it, up to the end of the selector, as in css-loader. It was a build error. - The scrollbar states (`a:horizontal`, `::-webkit-scrollbar{&:horizontal{}}`) are valid in a plain compound, as in WebKit and Blink. - Without browser targets, `-webkit-box-align`, `-ms-flex-align` and the like were dropped next to their standard form (flatpickr, foundation-sites, materialize-css: 28 stylesheets), and `-webkit-fill-available` before `-moz-available` (beercss). - `(-o-min-device-pixel-ratio: 2/1)` printed as `2`. - `sin()`, `cos()` and `tan()` are exact at multiples of 90deg: `calc(100px * cos(90deg))` printed `-.00000437114px`. - A `display-p3` color at targets that have P3 but not the other `color()` spaces (Safari 10.1 to 14) got itself as a fallback. - `width: rem(-18px, 5px)` folds to a negative literal once `rem()` is right; it prints `0`. - Consecutive nested declarations rules, which arise when same-query `@media` blocks in one rule merge, are folded into one and count against the existing selector expansion limit as the `&{}` rules they replace did. #### Known and not fixed here - Four longhands are still folded into a `transition` the author did not write where the targets add a prefixed copy of a property (`mask-image` at Chrome 80): only the shorthand gives the copy its own times. - A later `background`, `box-shadow` or `border-*` declaration still loses to the `@supports` copy of an earlier `var()` value of the same property with a wide-gamut color. Same on `main`; #45560 is taken for the properties of the fallback handler and for unparsed values only. - A merged rule prints the unprefixed name in the passes of the rule it absorbed: `.d::-webkit-input-placeholder{}.d::-moz-placeholder{}` prints `::placeholder` for the second (#42106, not taken: it breaks the merge of prefix-equivalent rules). - The `border`, `outline` and `font` shorthands, `line-height`, `scroll-padding`, `background-size` and a few more still print a `calc()` that folds below zero as a negative literal. No real stylesheet has one. - `all` is not a property Bun knows, so `a{margin-top:1px;all:unset}` prints `all` first. Same on `main`. - A selector kept as raw tokens loses the blank before `*` when minified: `--sel: .dark *` prints `.dark*`. Same on `main`. - `width:calc(0% + 12px)` folds to `12px`, which lays out differently in a table cell. Same on `main`. - The `:dir()` / `:lang()` rules of a lowered logical property print before the nested rules of their rule, so a logical declaration written after a nested rule of equal specificity still loses to it. Same on `main`. - A fraction is still rounded to 6 significant digits (`12345.678` prints `12345.7`, `33.3333333333%` prints `33.3333%`). Keeping every digit would add up to 282 KB over the corpus. - `@keyframes "quoted"` is hashed in a module but not exported. - In a module, a keyframes name inside a `var()` fallback is not hashed: `animation: var(--enter, fade 1s)`. Same on `main`. - A `color-mix()` or relative color folded to a hex inside a gradient changes the interpolation from Oklab to sRGB (VS Code, clawhub). Printing `color(srgb ..)` instead needs a fallback for `mask-image`, `list-style-image` and custom properties at the default targets, which have none. - A comma list in `@container` still fails the build. - After a bare `:global`, names that are hashed at print time (`::view-transition-old(foo)`) are still hashed; inside `:global(...)` they are not. #### Pull requests in scope that do not land here - Duplicates of a pull request that lands here: #36961 (of #37979), #38478 (of #46662), #38480 (of #46733), #38482 (of #46715), #38491 (of #38500), #38508 (of #45201), #38513 (of #45362), #38573 (of #45487), #38640 (of #38500), #45525 (of #45247), #45589 (of #46756), #45970 (of #45971) - Already fixed on `main`: #38674 - Right, but for input nobody writes (0 of 10,116 stylesheets, and not new syntax): #31916, #38526, #38592, #39349, #41139, #41801, #42042, #42484, #43078, #45604, #45908, #46086, #46221, #46224, #46273, #46694, #46707, #46737, #46755, #46816, #46870, #46934 - Right or harmless, but not worth their code, their bigger output or the behavior they change: #30905, #31924, #33332, #34426, #36225, #38006, #38512, #38547, #38551, #38561, #38572, #38576, #38607, #38623, #38667, #38692, #42106, #42912, #42918, #43407, #43434, #44700, #45442, #45546, #45747, #45759, #45825, #45946, #46061, #46127, #46206 - Need a decision (see above), stay open: #40368, #40369, #44647, #44648, #45814 - Stays open: #45787 Out of scope: CSS linking and chunking in the bundler, the dev server, docs-only pull requests, and repository-wide sweeps that touch `src/css` in passing. Thanks to @mikamikasuki (#45247), @alii (#39520, #31999) and @oddharsh, whose measurements on #40369 and #41990 were used. Fixes #16727. Fixes #24770. Fixes #30772. Fixes #44704. Fixes #45089. Fixes #45237. Fixes #46872. ### How did you verify your code works? - The 35 CSS test files pass on a debug build, also with `FORCE_COLOR=1`. 600+ of the tests in this branch fail on a build of `main`. An earlier head of this branch passed all 179 CI jobs that ran. - The reproduction of each issue listed above was run on `main` (wrong) and on this branch (right). - Differential run over the 10,116 stylesheets, `main` against this branch, minified without targets and through `Bun.build` at the default targets: no stylesheet that builds on `main` fails; Chromium 156 compares the output with the input rule by rule (CSSOM, then computed values on a sized element in a standards-mode document, colors as painted pixels in sRGB and P3). The comparison has 195 control pairs that must read equal or different. For stylesheets that read differently on both builds, mostly because of lowering, the sets of differences were compared; the three new ones are two minifier fixtures that are wrong on both and one comparison artifact. - CSS modules are checked for consistency instead, since hashed names defeat the comparison: every reference points at a name the output defines, every export exists. - `Bun.color`: 59 inputs in 13 formats on both builds; every changed cell was read.
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The part of this change that changes no output, the copies in the fold, is in #47267 ( |
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Problem
calc()sum holdsBun.color()for 5.7 s (1.3.11: 2 ms) andbun pm difffor 3.2 s.bun builddies with SIGSEGV inCalc<..>::deep_cloneand prints nothing.Calc::Sumwas a binary tree, oneBoxlevel per term (src/css/values/calc.rs). Each pass recursed per term, and both folds cloned it per level.Fix
Calc::Sumholds one list,SumTerms, that only its module builds.SumBuilderfolds it.0%and has no order. A lone sum inmin(),max()orhypot()keeps a function.calc-long-sum.test.tsand 99 of 1,628 incss.test.ts. Self-reviewed: 32 concerns raised, 29 addressed, 3 rejected (Notes).Background
Calc<V>is a parsed math expression. A length-percentage keeps a sum it cannot reduce. A value folds into the term of its unit.auto) or to a size below zero.Downsides
width:-2px, which browsers reject: 80 of 64,484 enumerated rows (css: treat out-of-range and unit-less numeric values as invalid instead of merging or repairing them #42104).calc(100% - 10px): +30 instructions inparse_sum, 7 fewer mallocs.Notes
Question for a maintainer. Draft #45415 (bun:dom) changes the same fold: it removes the zero checks of
DimensionPercentage::add_impl, which this PR deletes, and it makessign_f32return a zero as it is. It pins three rows. This PR agrees on one:height:sourcecalc(0% + 5px)5pxcalc(0% + 5px)calc(0% + 5px)calc(0% + 0px)00%calc(0% + 0px)calc(50% - 0px)50%50%calc(50% - 0px)The difference is a length of zero beside a percentage. This PR leaves it out, as main does. Evidence for the draft's rows: in Chrome 153 a table row or cell with
height: calc(80% + 0px)is 80px high in a 240px table, and withheight: 80%it is 192px. Cost of the draft's rows:calc(100% - 0px)stays a sum. The rule has one place here,CalcValue::zero_in_sum. The fold does not read the sign of a zero value: with thesign_f32of the draft applied to this branch,css.test.tspasses unchanged. Which rows do you want? If the answer needs a debate, the commit34ee5573f4can become a PR stacked on the list.The output changes, with examples. Each row is pinned in
css.test.ts.top: calc(50% - (calc(0.2px + 0.05em) / 2))(uikit)calc(50% + -.1px - .025em)calc(50% - .1px - .025em)width: calc(3rem + calc(1.5em + 0.75rem))(Bootstrap 5)calc(1.5em + 3.75rem)calc(3.75rem + 1.5em)height: calc(10% + 2px - 10%)2pxcalc(0% + 2px)margin-left: calc(0% + 1.25rem / 2)(Foundation).625remcalc(0% + .625rem)height: calc((1px + 10%) + (1px - 10%))calc(2px - 10% + 10%)calc(2px + 0%)background-position: max(0% + 0px, 20%) 0max(0px,20%) 0max(0%,20%) 0width: clamp(10%, 5%, 20%)10%clamp(10%,5%,20%)width: min(1px + 1em)1px + 1em(not valid)calc(1px + 1em)width: hypot(1px + 1em)1px + 1em(not valid)hypot(1px + 1em)Calc::sumputs the terms of a sum operand into the sum, and each value folds into the term of its unit. Main folded at most one pair of values between two sums. Stylo and CSS Values 4 keep a sum as one list too.percentage_basis_knownindim_pct_protocol!. It is false for a length-percentage and true for an angle-percentage (a part of a turn). A percentage that is a number (opacity) has no such fact and folds as before. CSS Values 4 says: "Zero-valued terms cannot be simply removed from a Sum", and "percentages might resolve against a negative basis". The web platform testcss/css-values/calc-serialization-002.htmlexpectscalc(0% + 1em)forcalc(100% - 100% + 1em). lightningcss drops the zero and orders the percentages. A length of zero is left out as before.css.test.tshere. Without change 3, change 2 makesmin(10% - 10% + 2px)print0% + 2px.bun pm diffcalls a file "formatting only" when both sides print the same. With change 2 it reportsheight: calc(10% + 2px - 10%)againstheight: 2pxas a change. With change 1 it does not reportcalc(1px + (1em + 2px))againstcalc(3px + 1em). One test incss.test.tspins both.Measured. Release builds on the base
f0c6cbc81a, all made in one directory: main, the list alone (the first two commits), and this PR. The branch was rebased after that, with no change insrc/css.Bun.color("hsl(atan2(<difference of N terms>, 1px) 50% 50%)"), 400 terms (6 KB) and 800 terms (12 KB): 1.2.16 2.2 ms and 6.8 ms. 1.3.11 2.3 ms and 7.0 ms. 1.4.0 2.7 s and 30 s. 1.4.3 6.3 s and 63 s. Main 5.7 s and 64 s. This PR 1.3 ms and 1.4 ms.bun pm diffof a package that adds a 6 KB stylesheet: 1.4.3 2.9 s, main 3.2 s, this PR 0.01 s. With a 3 MB stylesheet (a sum of 200,000 terms): 1.4.3 and main die with SIGSEGV and print no diff, this PR exits 0 in 0.19 s.bun build, main -> this PR: a difference of 400 terms 3.6 s -> 0.02 s of CPU, of 800 terms 36 s -> 0.02 s. 3,000 terms plus1vw979 MB -> 26 MB (a debug build with ASAN: 2,005 MB -> 336 MB, which is what that build takes for any stylesheet).@media (width > calc(8,000 terms))10.4 s and 6.9 GB -> 0.04 s and 26 MB. 30,000 terms: SIGSEGV with nothing on stdout or stderr -> exit 0. 1,000,000 terms: exit 0 on 9 of 9 entry points, about 1 s of CPU each.outline-widthrows differ, and 33,926 of 173,088widthrows, each with a percentage that is zero at some point of the sum. Sums with a sum operand: 44,058 of 128,968 rows differ.min(),max()andhypot()of one sum: main prints 25,113 of 34,200 rows with no function, this PR 0. A check of the value, unit by unit, finds 0 wrong rows in the 386,256 sums on both. A second minify changes 0 of 420,456 rows here.widthrows, the list alone 47,010, this PR 0.width: max(<sum>, 20%)reduced to one value: main 4,890 of 71,684 rows, the list alone 5,038, this PR 0.heightin a parent of unknown height and ofwidthafterwidth:123px: rows that lay out unlike their source: main 20,659 of 71,684, the list alone 20,855, this PR 2,759. Each of the 2,759 is one bare negative length, and 80 of them are new against main.test/js/bun/css/filesand 174 of the WebKit tree that usecalc(). 165 build. Three change: uikit (1 declaration, 1 byte less), bootstrap-5.3.7 (2, the order of two terms), Foundation (3, 11 bytes more each)..text+13,824. The symbols ofcalc.rs,percentage.rsandlength.rs245,331 -> 257,233 bytes.parse_sumto its return (gdbstepi), main -> this PR: first argument ofmin(10px,1em)1,788 -> 1,798, ofclamp(10px,1em,2vh)1,889 -> 1,899,calc(10px + 2px)4,393 -> 4,400,calc(100% - 10px)5,049 -> 5,079,calc(100% - 10px + 2em)8,320 -> 8,207.width: calc(Npx)width: calc(Npx + 2px)width: min(Npx,1em)width: clamp(Npx,1em,2vh)width: calc(100% - Npx)width: calc(100% - Npx + 2em)width: calc(100% - Npx + 2em - 1vh)width: calc(100% - (1rem + Npx))outline-width: calc(1em + Npx)height: calc(10% + Npx - 10%)margin-left: calc(0% + Nrem / 2)bun build --no-bundle, 50,000 declarations, 7 interleaved runs, median, spread about 5%), main -> this PR:width: Npx2,008 ns -> 1,987 ns,min(Npx,1em)2,787 -> 2,780,clamp(Npx,1em,2vh)2,808 -> 2,814,calc(Npx + 2px)2,310 -> 2,264,calc(100% - Npx)2,914 -> 2,708,calc(100% - (1rem + Npx))3,804 -> 3,234,height: calc(10% + Npx - 10%)2,636 -> 3,000.(1px + <sum>) - 1pxaround 77,000 terms (1.2 MB): 0.49 s. Main needs 0.4 s for 1 level around 2,000 terms.min(1px, 1em + min(...)): a release build holds 511 levels on main and here, and 512 givesMaximum CSS nesting depth exceededon both. A debug build with ASAN holds 251 here.anyforallinis_compatible, and no list of the positions of the values (22,500 values after 22,500 terms then take 17.9 s, against 1.5 s).mordantreports nothing withValuePositions.Not fixed here.
width: calc(1px - 3px)prints-2pxon main too. The fold cannot know the range of the property. css: treat out-of-range and unit-less numeric values as invalid instead of merging or repairing them #42104 has the range check.sign()of a sum that keeps0%is not a number, socalc(sign(10% - 10% + 2px) * 1px)stays as written, where main printed1px. Afterwidth:5pxin the same rule, such a value is printed before it (css: keep an unparsed width/height/color after the declarations written before it #42101, older), and the page shows 5px.0%holds the first place, socalc(0% - 1px - 10% + 9%)printscalc(--1% - 1px), where main printedcalc(-1px - 1%). 0 of 237,572 enumerated rows are new.*or/over a long sum costs terms times operators: 8,000 terms and 8,000 operators take 0.7 s here and 1.7 s on main. A second session has it, with no PR yet.Calc::reduce_argsis quadratic in the arguments ofmin()andmax(): 40,000 math functions and 40,000 values take 0.6 s on both. Handed to a second session./3.40282e38(older, css: print numbers from the f32's shortest digits, not its f64 expansion #38565 has the second minify). Handed to a second session.calc(-1 * (1px - 10%) + 1em)changes the order of its first two terms on a second minify, on main too.composeschain still overflows (bundler: keep deep CSS, export star and composes graphs from overflowing the linker's stack #38966).Percentage::from_calcgives NaN for a sum it cannot reduce (css: parse number and percentage channels in lab(), lch(), oklab(), oklch(), hsl() and hwb() #45084 removes it).Other PRs on this code.
add_impl, at the rowscalc(0% + 0px)andcalc(50% - 0px), and atsign_f32.min()ormax()(assingle_argument, with the rows of css: wrap a one-argument min()/max() sum or product in calc() #38654), and it giveshypot()one fold for every argument count. The two PRs conflict atparse_min_maxandparse_hypot. The second to merge drops its copy of the wrap and of the rows.DimensionPercentage::add_implandLength::add__to stop a cycle betweenCalc::addand the add of the value. This PR deletes both arms, because the cycle is gone: a value never adds throughCalcagain. The four rows of Fix calc bug #20174 pass unchanged. Main's output for a sum operand is a side effect of that fix: 1.2.15 printed-2pxforcalc((1em - 1px) - (1px + 1em)), as this PR does.Calc::Sum { left, .. }: the second of the two to merge must change it. css: parse number and percentage channels in lab(), lch(), oklab(), oklch(), hsl() and hwb() #45084, draft css: eliminate all unreachable!() via type-level hardening #33332, css: bump the default browser targets to Vite's baseline widely available set #40369 and css: print negative numbers below 1 with a single minus sign #38516 touch the same files.robobun/c6ae1587/css-calc-add-without-copies(no PR) removes only the copies of the fold, with no change of output. The tree stays, and so does its overflow.Self-review. Rejected: to keep the zero commit out of this PR, to put it under the list, and to send the small no-copies commit first. The request was one PR for both faces, and the zero commit is the last one, so it can be split.
Deleted or renamed.
DimensionPercentage::add_recursive,add_impl,add_internaland the two sign helpers.Length::try_add,add__,is_zeroand the two sign helpers.Calc::deep_clone_boxedandCalc::add_value.Calc::addis nowadd_values, for the four types that cannot hold a sum.CalcValue::add_internalis gone, andfrom_calcmoved toScalarCalcValue, soLengthandDimensionPercentagehave nofrom_calc.