fix: output fewer bytes for negative zero

.oxlintrc.json

@@ -7,19 +7,32 @@
   "rules": {
     "array-callback-return": "error",
     "complexity": "error",
-    "eqeqeq": ["error", "always", { "null": "ignore" }],
+    "eqeqeq": [
+      "error",
+      "always",
+      {
+        "null": "ignore"
+      }
+    ],
     "guard-for-in": "error",
+    "import/no-cycle": "error",
     "import/no-duplicates": "error",
     "import/no-self-import": "error",
     "max-depth": "error",
-    "max-lines": ["error", { "max": 400 }],
+    "max-lines": [
+      "error",
+      {
+        "max": 400
+      }
+    ],
     "no-bitwise": "error",
     "no-case-declarations": "error",
     "no-duplicate-imports": "error",
     "no-empty": "error",
     "no-fallthrough": "error",
     "no-labels": "error",
     "no-nested-ternary": "error",
+    "no-param-reassign": "error",
     "no-promise-executor-return": "error",
     "no-prototype-builtins": "error",
     "no-redeclare": "error",
@@ -28,15 +41,32 @@
     "no-shadow": "error",
     "no-template-curly-in-string": "error",
     "no-throw-literal": "error",
-    "no-underscore-dangle": ["error", { "allow": ["_default"] }],
+    "no-underscore-dangle": [
+      "error",
+      {
+        "allow": ["_default"]
+      }
+    ],
     "no-unmodified-loop-condition": "error",
     "no-unnecessary-await": "error",
     "no-unreachable-loop": "error",
     "no-useless-assignment": "error",
+    "no-var": "error",
     "no-void": "error",
+    "object-shorthand": "error",
     "only-throw-error": "error",
     "oxc/no-accumulating-spread": "error",
-    "prefer-const": ["error", { "destructuring": "all" }],
+    "prefer-arrow-callback": "error",
+    "prefer-const": [
+      "error",
+      {
+        "destructuring": "all"
+      }
+    ],
+    "prefer-numeric-literals": "error",
+    "prefer-object-has-own": "error",
+    "prefer-object-spread": "error",
+    "prefer-rest-params": "error",
     "preserve-caught-error": "error",
     "promise/always-return": "error",
     "promise/no-nesting": "error",
@@ -45,22 +75,34 @@
     "unicorn/consistent-function-scoping": "error",
     "unicorn/no-array-for-each": "error",
     "unicorn/no-array-reduce": "error",
+    "unicorn/no-array-reverse": "error",
     "unicorn/no-instanceof-array": "error",
     "unicorn/no-unnecessary-slice-end": "error",
     "unicorn/no-useless-fallback-in-spread": "error",
     "unicorn/no-useless-spread": "error",
     "unicorn/prefer-array-find": "error",
     "unicorn/prefer-array-flat": "error",
+    "unicorn/prefer-array-flat-map": "error",
+    "unicorn/prefer-array-index-of": "error",
     "unicorn/prefer-array-some": "error",
+    "unicorn/prefer-date-now": "error",
+    "unicorn/prefer-default-parameters": "error",
+    "unicorn/prefer-global-this": "error",
     "unicorn/prefer-includes": "error",
+    "unicorn/prefer-math-min-max": "error",
     "unicorn/prefer-math-trunc": "error",
     "unicorn/prefer-modern-math-apis": "error",
     "unicorn/prefer-negative-index": "error",
     "unicorn/prefer-node-protocol": "error",
     "unicorn/prefer-number-properties": "error",
+    "unicorn/prefer-object-from-entries": "error",
+    "unicorn/prefer-optional-catch-binding": "error",
     "unicorn/prefer-regexp-test": "error",
     "unicorn/prefer-set-has": "error",
     "unicorn/prefer-set-size": "error",
+    "unicorn/prefer-string-replace-all": "error",
+    "unicorn/prefer-string-starts-ends-with": "error",
+    "unicorn/prefer-string-trim-start-end": "error",
     "unicorn/prefer-type-error": "error"
   },
   "env": {

README.md

@@ -6,7 +6,8 @@
 [PostCSS Calc] lets you reduce `calc()` references whenever it's possible.
 When an expression mixes units that cannot be combined exactly (such as `px`
 and `em`), or contains values only known at runtime (such as `var()`), the
-unresolved part is left for the browser's [W3C calc() implementation].
+unresolved part is left for the browser's [CSS Values 4][css-values-4]
+implementation.
 
 ## Installation
 
@@ -69,9 +70,8 @@ reduceCalc('min(50px, calc(2 * 40px))');
 // => 'calc(50px)'
 ```
 
-It accepts `precision`, `unwrapSingleValue`, the deprecated
-`unwrapSingleNegativeNumber` alias,
-`warnWhenCannotResolve`, `onParseError`, and `onWarn`:
+It accepts `precision`, `unwrapSingleValue`, `warnWhenCannotResolve`,
+`onParseError`, and `onWarn`:
 
 ```js
 const result = reduceCalc('calc(100% + var(--gap))', {
@@ -191,20 +191,20 @@ Example:
 With `mediaQueries: true`, this becomes:
 
 ```css
-@media (min-width: 200px) {
+@media (min-width: calc(200px)) {
   div {
     width: 100px;
   }
 }
 ```
 
+Add `unwrapSingleValue: true` to get the bare value, `(min-width: 200px)`.
+
 #### `selectors` (default: `false`)
 
 Reduces `calc()` functions found in selectors. Selectors do not accept
-`calc()` functions, so the plugin replaces them with their reduced values.
-Finite negative and fractional unitless results are serialized as bare values
-because a selector cannot contain a `calc()` function; the plugin enables the
-`unwrapSingleValue` automatically for selectors.
+`calc()` functions, so the plugin replaces them with their reduced values, as
+if `unwrapSingleValue` were enabled.
 
 ```js
 var out = postcss()
@@ -224,8 +224,8 @@ With `selectors: true`, this becomes `div:nth-child(3)`.
 
 #### `onParseError`
 
-Callback invoked when a `calc()` body fails to parse or simplify. Matches
-[`@csstools/css-calc`][csstools-css-calc]'s shape:
+Callback invoked with the error and the input value when a `calc()` body fails
+to parse or simplify:
 
 ```js
 postcss().use(
@@ -250,13 +250,13 @@ canonical-form decisions:
 - **Strict whitespace (§10.1).** `calc(2px+3px)` is invalid CSS (binary
   `+` / `-` require surrounding whitespace) and is preserved with a
   warning instead of reduced.
-- **Canonical operand order.** Commutative operands serialize
-  numeric-first, matching [`@csstools/css-calc`][csstools-css-calc]:
+- **Canonical operand order.** Sums serialize numbers first, then
+  dimensions in first-seen order, then unresolved terms:
   `calc(var(--foo) + 10px)` → `calc(10px + var(--foo))`.
 - **Zero buckets are kept.** `calc(100px - (100px - 100%))` →
   `calc(0px + 100%)`, not `100%` — [WPT calc-serialization-002][wpt-calc-serialization]
   requires the zero term because it carries the length-percentage type.
-- **Constant folding.** `calc(43 + pi)` now folds to `46.14159` (§10.7.1).
+- **Constant folding.** `calc(43 + pi)` now folds to `calc(46.14159)` (§10.7.1).
   Previously `pi` / `e` stayed symbolic.
 - **Distributive multiplication.** `calc(0.5 * (100vw - 10px))` becomes
   `calc(50vw - 5px)`.
@@ -270,7 +270,6 @@ canonical-form decisions:
   if you want validation behavior.
 
 [css-values-4]: https://www.w3.org/TR/css-values-4/
-[csstools-css-calc]: https://www.npmjs.com/package/@csstools/css-calc
 [wpt-calc-serialization]: https://github.com/web-platform-tests/wpt/blob/master/css/css-values/calc-serialization-002.html
 [jison]: https://github.com/zaach/jison
 
@@ -288,6 +287,7 @@ for the full guidelines. The project uses [pnpm](https://pnpm.io/).
 
 ```bash
 git clone git@github.com:postcss/postcss-calc.git
+cd postcss-calc
 git checkout -b patch-1
 pnpm install
 pnpm test
@@ -302,23 +302,8 @@ when changing parsing/simplification behavior:
 pnpm test:corpus:full
 ```
 
-Performance changes to the parser, analyzer, simplifier, or serializer should be
-checked with the benchmarks. `pnpm benchmark:arithmetic-chains` and
-`pnpm benchmark:nested-fallbacks` compare the working tree against `HEAD` using
-20 fresh-process paired blocks by default and write git-ignored schema-v2
-reports under `reports/benchmarks/`. Re-check a saved report with
-`pnpm benchmark:reanalyze <report>`. `pnpm benchmark:corpus` compares the whole
-pipeline with `@csstools/css-calc` on real-world expressions and is
-report-only.
-
-These benchmarks time only the parser (or, for the corpus, the whole reducer)
-on one machine, and a `pass` means "no regression detected at the declared
-margin", not "no change". Read [BENCHMARKS.md](BENCHMARKS.md) before
-interpreting results.
-
-The PostCSS benchmark awaits `postcss().process(...)`, and that await already
-triggers result stringification. It therefore does not add a redundant
-`result.css` access.
+Check performance changes with the benchmarks described in
+[BENCHMARKS.md](BENCHMARKS.md), and read it before interpreting results.
 
 ## [Changelog](CHANGELOG.md)
 
@@ -332,4 +317,3 @@ triggers result stringification. It therefore does not add a redundant
 [PostCSS Calc]: https://github.com/postcss/postcss-calc
 [PostCSS Custom Properties]: https://github.com/postcss/postcss-custom-properties
 [tests]: test/
-[W3C calc() implementation]: https://www.w3.org/TR/css3-values/#calc-notation

scripts/README.md

@@ -29,9 +29,23 @@ and software architecture, see [BENCHMARKS.md](../BENCHMARKS.md).
   from an observed effect during a run.
 - **`benchmark/compare-parser-benchmarks.js`** — reanalyzes one schema-v2 parser
   artifact and applies the uncertainty-aware runtime, slope, and growth gates.
+  The analysis is split across `benchmark/parser-analysis.js` (entry point and
+  sensitivity analysis), `parser-analysis-endpoints.js` (per-endpoint
+  intervals, process-order summaries), and `parser-analysis-verdicts.js`
+  (runtime, slope, and growth verdicts).
+- **`benchmark/corpus-analysis.js`** — recomputes corpus decisions from raw
+  observations and checks stored summaries against them. Its helpers are
+  `corpus-group-results.js` (per-group paired ratios and bootstrap intervals)
+  and `corpus-decisions.js` (statistical and practical verdicts).
+- **`benchmark/validate-corpus.js`** — validates corpus artifact structure. Its
+  helpers are `validate-corpus-metadata.js` (correctness and group metadata)
+  and `validate-corpus-measurements.js` (per-batch and per-measurement checks).
 - **`benchmark/benchmark-serialization.js`** — measures buffered serializer scaling for wide sums/products, nested calls, and nested opaque fallbacks.
 - **`harvest-github.js`** — scrapes real-world `calc()` expressions from
-  public GitHub into `test/corpus/github/expressions.txt`.
+  public GitHub into `test/corpus/github/expressions.txt`. Its helpers live in
+  `harvest/`: `queries.js` (search phrases and languages), `github.js` (paced
+  `gh` search and fetch with rate-limit backoff), and `extract.js` (comment- and
+  string-aware `calc()` extraction).
 - **`split-corpus.js`** — splits that file into `github-pure.txt` (feeds
   `benchmark/benchmark-corpus.js`/`show-divergences.js` below), `preprocessor.txt`, and
   `invalid.txt` (the latter two are used by real CI resilience tests).