Read the last token of a selector that ends in a nested pseudo-class

docs/api.md

@@ -11,21 +11,21 @@ Query contexts default to the factory document when omitted. `closest()`, `first
 
 | Method | Result |
 | --- | --- |
-| [`byClass(cls, context)`](../src/nwsapi.mts#L2972) | Returns elements with the class name. |
-| [`byId(id, context)`](../src/nwsapi.mts#L2970) | Returns elements with the ID. Duplicate IDs are allowed by default. |
-| [`byTag(tag, context)`](../src/nwsapi.mts#L2971) | Returns elements with the tag name. Use `*` for all elements. |
-| [`closest(selectors, element, callback)`](../src/nwsapi.mts#L2978) | Returns the nearest match, starting with the element, or `null`. |
-| [`compile(selector, mode, callback)`](../src/nwsapi.mts#L2980) | Compiles a selector into a resolver function. This is an advanced API. |
-| [`configure(option, clear)`](../src/nwsapi.mts#L2981) | Reads or changes options. Pass `true` as the second argument to clear compiled selectors. |
-| [`emit(message, proto)`](../src/nwsapi.mts#L2983) | Reports an error using the configured error policy. |
-| [`first(selectors, context, callback)`](../src/nwsapi.mts#L2974) | Returns the first matching descendant, or `null`. |
-| [`install(all)`](../src/nwsapi.mts#L2989) | Replaces native selector methods. Pass `true` to also replace collection methods. |
-| [`match(selectors, element, callback)`](../src/nwsapi.mts#L2975) | Returns whether the element matches. |
-| [`registerCombinator(combinator, resolver)`](../src/nwsapi.mts#L2996) | Adds a relationship between elements using trusted resolver code. |
-| [`registerOperator(operator, resolver)`](../src/nwsapi.mts#L3021) | Adds an attribute operator using a resolver with `p1`, `p2`, and `p3` fields. |
-| [`registerSelector(name, rexp, func)`](../src/nwsapi.mts#L3043) | Adds a selector pattern and a compiler callback that returns `source` and `status`. |
-| [`select(selectors, context, callback)`](../src/nwsapi.mts#L2976) | Returns an array of matching descendants, or an empty array. |
-| [`uninstall()`](../src/nwsapi.mts#L2990) | Restores the native methods saved by `install()`. |
+| [`byClass(cls, context)`](../src/nwsapi.mts#L2982) | Returns elements with the class name. |
+| [`byId(id, context)`](../src/nwsapi.mts#L2980) | Returns elements with the ID. Duplicate IDs are allowed by default. |
+| [`byTag(tag, context)`](../src/nwsapi.mts#L2981) | Returns elements with the tag name. Use `*` for all elements. |
+| [`closest(selectors, element, callback)`](../src/nwsapi.mts#L2988) | Returns the nearest match, starting with the element, or `null`. |
+| [`compile(selector, mode, callback)`](../src/nwsapi.mts#L2990) | Compiles a selector into a resolver function. This is an advanced API. |
+| [`configure(option, clear)`](../src/nwsapi.mts#L2991) | Reads or changes options. Pass `true` as the second argument to clear compiled selectors. |
+| [`emit(message, proto)`](../src/nwsapi.mts#L2993) | Reports an error using the configured error policy. |
+| [`first(selectors, context, callback)`](../src/nwsapi.mts#L2984) | Returns the first matching descendant, or `null`. |
+| [`install(all)`](../src/nwsapi.mts#L2999) | Replaces native selector methods. Pass `true` to also replace collection methods. |
+| [`match(selectors, element, callback)`](../src/nwsapi.mts#L2985) | Returns whether the element matches. |
+| [`registerCombinator(combinator, resolver)`](../src/nwsapi.mts#L3006) | Adds a relationship between elements using trusted resolver code. |
+| [`registerOperator(operator, resolver)`](../src/nwsapi.mts#L3031) | Adds an attribute operator using a resolver with `p1`, `p2`, and `p3` fields. |
+| [`registerSelector(name, rexp, func)`](../src/nwsapi.mts#L3053) | Adds a selector pattern and a compiler callback that returns `source` and `status`. |
+| [`select(selectors, context, callback)`](../src/nwsapi.mts#L2986) | Returns an array of matching descendants, or an empty array. |
+| [`uninstall()`](../src/nwsapi.mts#L3000) | Restores the native methods saved by `install()`. |
 
 <details>
 <summary>Configuration</summary>
@@ -58,22 +58,22 @@ These exports support extensions and debugging. Prefer query methods and `config
 
 | Member | Purpose |
 | --- | --- |
-| [`CFG`](../src/nwsapi.mts#L2958) | Contains the compiler syntax settings. |
-| [`Config`](../src/nwsapi.mts#L2984) | Contains the active options. Use `configure()` to change them. |
-| [`M_BODY`](../src/nwsapi.mts#L2961) | Contains the matching resolver body template. |
-| [`M_TEST`](../src/nwsapi.mts#L2965) | Contains the matching resolver test template. |
-| [`matchLambdas`](../src/nwsapi.mts#L2950) | Caches compiled matching functions, not DOM results. |
-| [`matchResolvers`](../src/nwsapi.mts#L2953) | Caches matching plans, not DOM results. |
-| [`N_BODY`](../src/nwsapi.mts#L2962) | Exposes the matching resolver body template. |
-| [`N_TEST`](../src/nwsapi.mts#L2966) | Contains the alternate resolver test template. |
-| [`Operators`](../src/nwsapi.mts#L2992) | Contains registered attribute operators. |
-| [`S_BODY`](../src/nwsapi.mts#L2960) | Contains the selection resolver body template. |
-| [`S_TEST`](../src/nwsapi.mts#L2964) | Contains the selection resolver test template. |
-| [`selectLambdas`](../src/nwsapi.mts#L2951) | Caches compiled selection functions, not DOM results. |
-| [`Selectors`](../src/nwsapi.mts#L2993) | Contains registered selector extensions. |
-| [`selectResolvers`](../src/nwsapi.mts#L2954) | Caches selection plans, not DOM results. |
-| [`Snapshot`](../src/nwsapi.mts#L2985) | Contains the document state and helpers used by compiled selectors. |
-| [`Version`](../src/nwsapi.mts#L2987) | Contains the engine version string. |
+| [`CFG`](../src/nwsapi.mts#L2968) | Contains the compiler syntax settings. |
+| [`Config`](../src/nwsapi.mts#L2994) | Contains the active options. Use `configure()` to change them. |
+| [`M_BODY`](../src/nwsapi.mts#L2971) | Contains the matching resolver body template. |
+| [`M_TEST`](../src/nwsapi.mts#L2975) | Contains the matching resolver test template. |
+| [`matchLambdas`](../src/nwsapi.mts#L2960) | Caches compiled matching functions, not DOM results. |
+| [`matchResolvers`](../src/nwsapi.mts#L2963) | Caches matching plans, not DOM results. |
+| [`N_BODY`](../src/nwsapi.mts#L2972) | Exposes the matching resolver body template. |
+| [`N_TEST`](../src/nwsapi.mts#L2976) | Contains the alternate resolver test template. |
+| [`Operators`](../src/nwsapi.mts#L3002) | Contains registered attribute operators. |
+| [`S_BODY`](../src/nwsapi.mts#L2970) | Contains the selection resolver body template. |
+| [`S_TEST`](../src/nwsapi.mts#L2974) | Contains the selection resolver test template. |
+| [`selectLambdas`](../src/nwsapi.mts#L2961) | Caches compiled selection functions, not DOM results. |
+| [`Selectors`](../src/nwsapi.mts#L3003) | Contains registered selector extensions. |
+| [`selectResolvers`](../src/nwsapi.mts#L2964) | Caches selection plans, not DOM results. |
+| [`Snapshot`](../src/nwsapi.mts#L2995) | Contains the document state and helpers used by compiled selectors. |
+| [`Version`](../src/nwsapi.mts#L2997) | Contains the engine version string. |
 
 </details>
 

package.json

@@ -117,6 +117,7 @@
     "upstream:verify": "node scripts/run.mts scripts/git-partial-submodule.mts verify",
     "test:attributes": "node scripts/run.mts node_modules/vitest/vitest.mjs run --config .config/vitest.config.mts test/attribute-parse-error.test.mts",
     "test:attributes:browser": "NWSAPI_BROWSER=1 node scripts/run.mts node_modules/vitest/vitest.mjs run --config .config/vitest.config.mts test/attribute-strings-browser.test.mts",
-    "test:browser": "NWSAPI_BROWSER=1 node scripts/run.mts node_modules/vitest/vitest.mjs run --config .config/vitest.config.mts"
+    "test:browser": "NWSAPI_BROWSER=1 node scripts/run.mts node_modules/vitest/vitest.mjs run --config .config/vitest.config.mts",
+    "test:optimizer": "node scripts/run.mts node_modules/vitest/vitest.mjs run --config .config/vitest.config.mts test/optimizer-nesting.test.mts"
   }
 }

src/nwsapi.mts

@@ -1212,7 +1212,8 @@
       // pairs, coloring breakage and other editors highlightning problems.
       //
 
-      var // non-ascii chars
+      var parenthesized,
+        // non-ascii chars
         noascii = '[^\\x00-\\x9f]',
         // unicode chars
         unicode = '\\\\[0-9a-fA-F]{1,6}',
@@ -1348,6 +1349,15 @@
       // deepest localName in selector strings and then
       // use it to retrieve all possible matching nodes
       // that will be filtered by compiled resolvers
+      // The parenthesized part has to tolerate nesting. Written as
+      // '\x28[^\x29]+' it stops at the first ')', so a final compound
+      // holding a nested functional pseudo-class matches nothing at all, and
+      // a selector the optimizer cannot read is answered by testing every
+      // element in the context instead of the elements of one tag or class.
+      parenthesized = '\\x28[^\\x28\\x29]*(?:\\x29|$)'
+      parenthesized = '\\x28(?:[^\\x28\\x29]|' + parenthesized + ')*(?:\\x29|$)'
+      parenthesized = '\\x28(?:[^\\x28\\x29]|' + parenthesized + ')*(?:\\x29|$)'
+
       reOptimizer = RegExp(
         '(?:([.:#*]?)' +
           '(' +
@@ -1356,7 +1366,7 @@
           '(?:' +
           ':[-\\w]+|' +
           '\\[[^\\]]+(?:\\]|$)|' +
-          '\\x28[^\\x29]+(?:\\x29|$)' +
+          parenthesized +
           ')*)$',
       )
 

test/optimizer-nesting.md

@@ -0,0 +1,11 @@
+# Nested optimizer regression
+
+Run with Node.js ≥ 22:
+
+```sh
+pnpm install
+pnpm run test:optimizer
+```
+
+The tests check strict factory initialization and nested selector results,
+including cached queries. jsdom supplies an independent reference engine.

test/optimizer-nesting.test.mts

@@ -0,0 +1,47 @@
+const __dirname = import.meta.dirname
+import { createRequire } from 'node:module'
+const require = createRequire(import.meta.url)
+const assert = require('node:assert/strict')
+const { readFileSync } = require('node:fs')
+const { join } = require('node:path')
+import { test } from 'vitest'
+const vm = require('node:vm')
+const { JSDOM } = require('jsdom')
+const source = readFileSync(join(__dirname, '../src/nwsapi.js'), 'utf8')
+
+test('strict factory initialization does not leak parser variables', () => {
+  const context = {
+    module: { exports: {} as (host: unknown) => unknown },
+    exports: {},
+  }
+  vm.runInNewContext('"use strict";\n' + source, context)
+  const { window } = new JSDOM('<!doctype html><div></div>')
+  try {
+    assert.doesNotThrow(() => context.module.exports(window))
+    assert.equal(Object.hasOwn(context, 'parenthesized'), false)
+  } finally {
+    window.close()
+  }
+})
+
+for (const selector of [
+  'div:not(:nth-of-type(2n))',
+  'div:not(:nth-child(3))',
+  'div:is(.a):not(:where(.b))',
+  'div:not(:not(:not(span)))',
+  'div:has(:is(.a .b))',
+]) {
+  test(selector, () => {
+    const { window } = new JSDOM(
+      '<!doctype html><div id=a class=a><span class=a><i class=b></i></span></div><div id=b class=b></div><div id=c class=a></div>',
+    )
+    try {
+      const nw = require('../src/nwsapi')(window)
+      const expected = [...window.document.querySelectorAll(selector)]
+      assert.deepEqual(nw.select(selector), expected)
+      assert.deepEqual(nw.select(selector), expected, 'cached selection')
+    } finally {
+      window.close()
+    }
+  })
+}