[html] fix TypeError in nth-child query selector #2015

sstasi95 · 2025-02-06T12:51:32Z

This PR fixes a type error occurring when parsing an nth-child query selector with a non numerical value, e.g. nth-child(even).

Exception:
_TypeError (type 'Identifier' is not a subtype of type 'num' in type cast)

Example html code:

<!DOCTYPE html>
<head>
    <style>
        li:nth-child(even) {
            color: red;
        }
    </style>
</head>
<body>

    <h2>List Example</h2>
    <ul>
        <li>Item 1</li>
        <li>Item 2</li>
        <li>Item 3</li>
        <li>Item 4</li>
        <li>Item 5</li>
    </ul>

</body>
</html>

I'm not sure if and where I should add a test for this.

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kevmoo · 2025-02-06T18:26:51Z

We'd want tests here, please

github-actions · 2025-02-06T18:27:32Z

PR Health

Breaking changes ✔️

Package	Change	Current Version	New Version	Needed Version	Looking good?
html	None	0.15.5+1	0.15.6-wip	0.15.5+1	✔️

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Package	Changed Files

Changes to files need to be accounted for in their respective changelogs.

Coverage

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File	Coverage
pkgs/html/lib/src/query_selector.dart	💔 68 % ⬇️ 2 %

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API leaks

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The following packages contain symbols visible in the public API, but not exported by the library. Export these symbols or remove them from your publicly visible API.

Package	Leaked API symbols
html	HtmlTokenizer Token HtmlInputStream TagToken DoctypeToken StringToken TreeBuilder ActiveFormattingElements StartTagToken TagAttribute CommentToken CharactersToken SpaceCharactersToken EndTagToken

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// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

Files
pkgs/html/lib/src/query_selector.dart

All source files should start with a license header.

Unrelated files missing license headers

Files
pkgs/bazel_worker/benchmark/benchmark.dart
pkgs/bazel_worker/example/client.dart
pkgs/bazel_worker/example/worker.dart
pkgs/benchmark_harness/integration_test/perf_benchmark_test.dart
pkgs/boolean_selector/example/example.dart
pkgs/clock/lib/clock.dart
pkgs/clock/lib/src/clock.dart
pkgs/clock/lib/src/default.dart
pkgs/clock/lib/src/stopwatch.dart
pkgs/clock/lib/src/utils.dart
pkgs/clock/test/clock_test.dart
pkgs/clock/test/default_test.dart
pkgs/clock/test/stopwatch_test.dart
pkgs/clock/test/utils.dart
pkgs/coverage/lib/src/coverage_options.dart
pkgs/coverage/test/collect_coverage_config_test.dart
pkgs/coverage/test/config_file_locator_test.dart
pkgs/html/example/main.dart
pkgs/html/lib/dom.dart
pkgs/html/lib/dom_parsing.dart
pkgs/html/lib/html_escape.dart
pkgs/html/lib/parser.dart
pkgs/html/lib/src/constants.dart
pkgs/html/lib/src/encoding_parser.dart
pkgs/html/lib/src/html_input_stream.dart
pkgs/html/lib/src/list_proxy.dart
pkgs/html/lib/src/token.dart
pkgs/html/lib/src/tokenizer.dart
pkgs/html/lib/src/treebuilder.dart
pkgs/html/lib/src/utils.dart
pkgs/html/test/dom_test.dart
pkgs/html/test/parser_feature_test.dart
pkgs/html/test/parser_test.dart
pkgs/html/test/query_selector_test.dart
pkgs/html/test/selectors/level1_baseline_test.dart
pkgs/html/test/selectors/level1_lib.dart
pkgs/html/test/selectors/selectors.dart
pkgs/html/test/support.dart
pkgs/html/test/tokenizer_test.dart
pkgs/pubspec_parse/test/git_uri_test.dart
pkgs/stack_trace/example/example.dart
pkgs/watcher/test/custom_watcher_factory_test.dart
pkgs/yaml_edit/example/example.dart

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github-actions · 2025-02-06T18:27:40Z

Package publishing

Package	Version	Status	Publish tag (post-merge)
package:bazel_worker	1.1.3	already published at pub.dev
package:benchmark_harness	2.3.1	already published at pub.dev
package:boolean_selector	2.1.2	already published at pub.dev
package:browser_launcher	1.1.3	already published at pub.dev
package:cli_config	0.2.1-wip	WIP (no publish necessary)
package:cli_util	0.4.2	already published at pub.dev
package:clock	1.1.2	already published at pub.dev
package:code_builder	4.10.2-wip	WIP (no publish necessary)
package:coverage	1.12.0	already published at pub.dev
package:csslib	1.0.2	already published at pub.dev
package:extension_discovery	2.1.0	already published at pub.dev
package:file	7.0.2-wip	WIP (no publish necessary)
package:file_testing	3.1.0-wip	WIP (no publish necessary)
package:glob	2.1.3	already published at pub.dev
package:graphs	2.3.3-wip	WIP (no publish necessary)
package:html	0.15.6-wip	WIP (no publish necessary)
package:io	1.1.0-wip	WIP (no publish necessary)
package:json_rpc_2	3.0.3	already published at pub.dev
package:markdown	7.3.1-wip	WIP (no publish necessary)
package:mime	2.0.0	already published at pub.dev
package:oauth2	2.0.4-wip	WIP (no publish necessary)
package:package_config	2.3.0-wip	WIP (no publish necessary)
package:pool	1.5.2-wip	WIP (no publish necessary)
package:pub_semver	2.2.0	already published at pub.dev
package:pubspec_parse	1.5.0	already published at pub.dev
package:source_map_stack_trace	2.1.3-wip	WIP (no publish necessary)
package:source_maps	0.10.14-wip	WIP (no publish necessary)
package:source_span	1.10.1	already published at pub.dev
package:sse	4.1.8	ready to publish	`sse-v4.1.8`
package:stack_trace	1.12.1	already published at pub.dev
package:stream_channel	2.1.4	already published at pub.dev
package:stream_transform	2.1.2-wip	WIP (no publish necessary)
package:string_scanner	1.4.1	already published at pub.dev
package:term_glyph	1.2.3-wip	WIP (no publish necessary)
package:test_reflective_loader	0.2.3	already published at pub.dev
package:timing	1.0.2	already published at pub.dev
package:unified_analytics	8.0.1	already published at pub.dev
package:watcher	1.1.1	already published at pub.dev
package:yaml	3.1.3	already published at pub.dev
package:yaml_edit	2.2.2	already published at pub.dev

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

sstasi95 · 2025-02-06T19:21:19Z

@kevmoo Sure, could you please point me to the file where I can add tests for this? I couldn't find any test for nth-child or similar.

HosseinYousefi

This is not enough to fix the issue. The issue is that our implementation of nth-child doesn't support the value of even. Here you are only ignoring this assumption. Instead the predicate should also be changed when the value is even ( parent.nodes.indexOf(_element) % 2 == 0).

As the TODO comment suggests, we do not support the An+B syntax either.

sstasi95 · 2025-04-17T15:30:34Z

@HosseinYousefi Hi, I'm not sure I understand your suggestion. I understand that even is not supported, and the goal of this PR is not to support it. This PR simply fixes an unsafe cast (literal.value as num) which is causing grey screens in production in our app.

Unfortunately in our app the html is coming from an external api, so we have no control over it.

HosseinYousefi · 2025-04-17T15:40:19Z

I suggest making this explicit then. Add a comment that we only support numeric values, and return false. For example

if (literal.value is! num) { 
  // The comment here...
  return false;
}

Regarding tests, there is no need to add one. It can be added once we actually add the support for other values like even or An+B

HosseinYousefi · 2025-04-17T15:45:58Z

Other than that please increment the version to from n to .(n+1)-wip and add a changelog

HosseinYousefi

LGTM! Thanks for your contribution!

[html] fix TypeError in nth-child query selector

77d449a

github-actions bot added the package:html label Feb 6, 2025

mosuem requested a review from HosseinYousefi April 17, 2025 12:40

HosseinYousefi requested changes Apr 17, 2025

View reviewed changes

sstasi95 and others added 3 commits April 17, 2025 18:56

[html] explicitly reject nth-child with non numeric values

609c109

[html] bump version

f239868

Merge branch 'main' into main

c8d30c7

HosseinYousefi approved these changes Apr 22, 2025

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HosseinYousefi merged commit 98d4e4d into dart-lang:main Apr 22, 2025
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[html] fix TypeError in nth-child query selector #2015

[html] fix TypeError in nth-child query selector #2015

sstasi95 commented Feb 6, 2025

kevmoo commented Feb 6, 2025

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sstasi95 commented Apr 17, 2025

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[html] fix TypeError in nth-child query selector #2015

[html] fix TypeError in nth-child query selector #2015

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sstasi95 commented Feb 6, 2025

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