Add 'excerpter' package to the tools repository

[kevmoo]

Migrate the excerpter package from dart-lang/labs to dart-lang/tools.

Core Package & Setup:

• Ported all core libraries, executable entry points, and tests to pkgs/excerpter.
• Adapted constraints to target Dart SDK ^3.12.0 and replaced the site-specific analysis_defaults with package:dart_flutter_team_lints.
• Structured a clean library programmatic usage example in example/main.dart.
• Exposed code ownership in .github/CODEOWNERS.
• Set up GitHub Actions CI workflow in .github/workflows/excerpter.yaml.
• Set up labeler patterns in .github/labeler.yml.
• Registered the excerpter package in the root README.md.

[github-actions]

Package publishing

Package	Version	Status	Publish tag (post-merge)
package:bazel_worker	1.1.5	already published at pub.dev
package:benchmark_harness	2.4.0	already published at pub.dev
package:boolean_selector	2.1.2	already published at pub.dev
package:browser_launcher	1.2.0-wip	WIP (no publish necessary)
package:cli_config	0.2.1-wip	WIP (no publish necessary)
package:cli_util	0.5.1	already published at pub.dev
package:clock	1.1.3-wip	WIP (no publish necessary)
package:code_builder	4.12.0-wip	WIP (no publish necessary)
package:coverage	1.15.0	already published at pub.dev
package:csslib	1.0.2	already published at pub.dev
package:excerpter	0.1.0-wip	WIP (no publish necessary)
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	2.4.0-wip	WIP (no publish necessary)
package:html	0.15.7-wip	WIP (no publish necessary)
package:io	1.1.0-wip	WIP (no publish necessary)
package:json_rpc_2	4.1.0	already published at pub.dev
package:markdown	7.4.0	ready to publish	markdown-v7.4.0
package:mime	2.1.0-wip	WIP (no publish necessary)
package:oauth2	2.0.5	already published at pub.dev
package:package_config	2.3.0-wip	WIP (no publish necessary)
package:pool	1.5.3-wip	WIP (no publish necessary)
package:process	5.0.5	(error) pubspec version (5.0.5) and changelog (5.0.6-wip) don't agree
package:pub_semver	2.2.0	already published at pub.dev
package:pubspec_parse	1.6.0-wip	WIP (no publish necessary)
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	1.10.2	already published at pub.dev
package:sse	4.2.0	already published at pub.dev
package:stack_trace	1.12.2-wip	(error) pubspec version (1.12.2-wip) and changelog (1.12.2-dev) don't agree
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	1.4.2-wip	WIP (no publish necessary)
package:term_glyph	1.2.3-wip	WIP (no publish necessary)
package:test_reflective_loader	0.6.0	ready to publish	test_reflective_loader-v0.6.0
package:timing	1.0.2	already published at pub.dev
package:unified_analytics	8.0.15	ready to publish	unified_analytics-v8.0.15
package:watcher	1.2.2-wip	WIP (no publish necessary)
package:yaml	3.1.4-wip	WIP (no publish necessary)
package:yaml_edit	2.2.4	already published at pub.dev

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

[github-actions]

PR Health

License Headers ✔️

// Copyright (c) 2026, 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
no missing headers

All source files should start with a license header.

Unrelated files missing license headers

Files
pkgs/bazel_worker/benchmark/benchmark.dart
pkgs/coverage/lib/src/coverage_options.dart
pkgs/html/example/main.dart
pkgs/pubspec_parse/test/git_uri_test.dart
pkgs/watcher/test/custom_watcher_factory_test.dart

This check can be disabled by tagging the PR with skip-license-check.

Breaking changes ⚠️

Package	Change	Current Version	New Version	Needed Version	Looking good?
excerpter	Breaking	0.0.0	0.0.0	0.0.0 Report was not created for package:excerpter 0.1.0-wip (dir=/home/runner/work/tools/tools/current_repo/pkgs/excerpter). Error: Error: Exception: Package not available (could not find package excerpter at https://pub.dev).	⚠️

This check can be disabled by tagging the PR with skip-breaking-check.

Coverage ⚠️

File	Coverage
pkgs/excerpter/bin/excerpter.dart	💔 Not covered
pkgs/excerpter/example/main.dart	💔 Not covered
pkgs/excerpter/lib/excerpter.dart	💔 Not covered
pkgs/excerpter/lib/src/extract.dart	💚 98 %
pkgs/excerpter/lib/src/inject.dart	💚 75 %
pkgs/excerpter/lib/src/transform.dart	💚 98 %
pkgs/excerpter/lib/src/update.dart	💚 100 %
pkgs/excerpter/test_data/example/dartdoc.dart	💔 Not covered
pkgs/excerpter/test_data/example/plaster.dart	💔 Not covered
pkgs/excerpter/test_data/example/simple_main.dart	💔 Not covered
pkgs/excerpter/test_data/example/simple_region.dart	💔 Not covered
pkgs/excerpter/test_data/example/transforms.dart	💔 Not covered

This check for test coverage is informational (issues shown here will not fail the PR).

This check can be disabled by tagging the PR with skip-coverage-check.

API leaks ✔️

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 symbol	Leaking sources

This check can be disabled by tagging the PR with skip-leaking-check.

Unused Dependencies ✔️

Package	Status
excerpter	✔️ All dependencies utilized correctly.

For details on how to fix these, see dependency_validator.

This check can be disabled by tagging the PR with skip-unused-dependencies-check.

Changelog Entry ✔️

Package	Changed Files

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

This check can be disabled by tagging the PR with skip-changelog-check.

[gemini-code-assist]

Code Review

This pull request introduces the excerpter package, a tool for synchronizing code excerpts in Markdown files with source code regions. It includes a CLI, a programmatic API, and various text transformations. Feedback focuses on improving the robustness of the instruction parser (specifically handling escaped quotes and delimiters), ensuring consistency between the documentation and regex for region names, and optimizing performance by pre-compiling regexes and sharing the extraction cache across multiple files.

[kevmoo]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces the excerpter package to the monorepo, a tool designed to synchronize code excerpts in Markdown files with regions defined in source code. The reviewer identified several areas for improvement, including a potential RangeError in inject.dart when handling short lines and a bug in the shared indentation logic that fails when excerpts contain empty lines. Additionally, the feedback suggests using the path package for more robust file extension detection and updating the README.md to reflect the package's new repository location and bug tracker links.

[kevmoo]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces a new package, excerpter, designed to update code excerpts in Markdown documentation from source files. The changes include the package structure, CLI implementation, and necessary configuration files. The review identified a discrepancy between the SDK version in the PR description and the pubspec.yaml, suggested simplifying argument parsing and error handling in the CLI, and pointed out an unnecessary await in pkgs/markdown/tool/update_shared.dart that conflicts with the unnecessary_await_in_return lint rule.

[kevmoo]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces the excerpter package, a tool for synchronizing code excerpts in Markdown documentation with source files. It includes a CLI, extraction and injection logic, and various text transformations. Review feedback identifies a potential path traversal vulnerability in path joining, suggests normalizing paths in the region cache to prevent redundant processing, and recommends replacing a magic number with a named constant.

[jonasfj]

@kevmoo please look at dart-lang/dartdoc#4144

Can talk to others and see if we can agree on something.

IMO, it's preferable if this is as simple as possible.

If we want to have substitution, what is the motivation? And are we sure the benefits outweigh the costs of duplicating a few examples.

I can see how a reference using skip=5 could be hard to maintain, how will I when editing the code file that contains the doc-region know that it's referenced somewhere with skip=5 and that this has to be meaningful.

I guess you'll be able to see it in the PR diff (if you read all the diff, but not if you skim it). But for something like {$example path/to/example/code.dart#myregion} a skip=5 option would be dangerous, because when editing path/to/example/code.dart I can see #region myregion but I can't really know that one place the region is used with skip-5 and in another it's not. And with dartdoc API doc changes won't be visible in the PR.

The same concern applies with substituions, etc. this is my main concern: too many features makes updating code examples dangerous, because it hard to know how the docregion is being referenced (and what substitutions it is subject to).

[jonasfj]

@parlough do you have some context on all the options here?

Do we need them? and is it really wise to have so many options.