[mustache_template] Add example app by princesoni18 · Pull Request #36 · flutter/core-packages

princesoni18 · 2026-08-02T08:35:54Z

Adds an example application for the mustache_template package and updates the README to be more high-level.

Previously the package had no example app (causing a pub.dev score deduction), and most of the documentation lived in the README. This PR moves the detailed examples into a proper example/ directory and cleans up the README.

Fixes flutter/flutter#183936

Pre-Review Checklist

This PR only adds an example app and improves documentation. It does not change any package code, so no version bump or CHANGELOG entry is required. It also falls under the test exemption for pure documentation / example changes.

Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling. ↩ ↩²

gemini-code-assist

Code Review

This pull request adds a new example package for mustache_template, including a main.dart file with usage examples and a pubspec.yaml file, and updates the .gitignore to exclude FVM cache. It also updates the README.md to reference these examples using code-excerpt markers. The review feedback highlights discrepancies between the code snippets in README.md and the actual implementations in example/lib/main.dart for exampleUsage, nestedPaths, and lambdasExample, which should be kept in sync.

stuartmorgan-g

Thanks for the contribution!

It does not change any package code, so no version bump or CHANGELOG entry is required. It also falls under the test exemption for pure documentation / example changes.

The exemption is for unpublished portions of the example; main.dart is published on pub.dev

Also, this PR does not appear to have had the formatter run on it, as indicated in the checklist, nor does it pass analysis.

stuartmorgan-g · 2026-08-03T15:45:49Z

 .settings
+
+# FVM Version Cache
+.fvm/


Ignores for local tools should be done in your user-level git ignore, not added to the repository.

stuartmorgan-g · 2026-08-03T15:46:12Z

+    path: ../
+
+dev_dependencies:
+  lints: ^3.0.0


We don't use lints.

stuartmorgan-g · 2026-08-03T15:47:43Z

-		{'firstname': 'Bob', 'lastname': 'Johnson'}
-	]});
+/// The main entrypoint for the example app.
+void main() {


None of this is relevant to the example; just the original code, omitting the main() and print, should be part of the excerpt.

stuartmorgan-g · 2026-08-03T15:49:06Z

+    'author': <String, String>{'name': 'Greg Lowe'},
+  });
+  print(output);
+}


And then more generally, you've significantly changed the structure of all of these examples, making them longer by adding unnecessary boilerplate. The code being excerpted should be structurally the same as it was, with the changes being those necessary to follow style rules.

stuartmorgan-g · 2026-08-03T15:54:33Z


 ## Example usage
+
+<?code-excerpt "main.dart (example_usage)"?>


This reference is not correct. Did you run the excerpting tool, or did you manually copy everything between the files?

princesoni18 · 2026-08-05T20:07:03Z

ok i will make the changes and update it ASAP!!

stuartmorgan-g · 2026-08-07T12:02:31Z

Regarding your comment in the issue about this PR, you will need to be running a current version of the repository tooling to correctly implement this. Targeting a version of the tooling that is more than three years old won't result in a PR that passes CI.

stuartmorgan-g · 2026-08-18T18:36:33Z

From triage: is this ready for re-review?

princesoni18 · 2026-08-20T20:25:08Z

yes this is ready for re-review with the changes

stuartmorgan-g

This PR needs to include removing the ci_config.yaml that exempts this package from excerpt enforcement.

stuartmorgan-g · 2026-09-09T13:57:11Z

What is the purpose of having this file? All of the code appears to exactly duplicate code in main.dart.

stuartmorgan-g · 2026-09-09T13:58:47Z

Why is this PR reformatting unrelated files?

None of these changes pass our formatting check. Code needs to be autoformatted using a recent version of Dart, and using our repository's line length settings.

stuartmorgan-g · 2026-09-09T14:01:59Z

+  // Simple lambda
+  var t1 = Template('{{# foo }}inner{{/ foo }}');
+  Object lambda1(Object? _) => 'bar';
+


You've removed the renderString line, which shows how to actually turn the template into a string and what the result of each example is, making the examples much less useful.

Adopting code excepts should not remove useful parts of examples.

stuartmorgan-g · 2026-09-09T14:02:29Z

+  Object lambda5(LambdaContext ctx) => ctx.renderSource('${ctx.source} {{cmd}}');
 ```

-In the following example `LambdaContext.renderSource(source)` re-parses the source string in the current context, this is the default behaviour in many mustache implementations. Since re-parsing the content is slow, and often not required, this library makes this step optional.


Why was the structure of the README changed here?

stuartmorgan-g · 2026-09-09T14:02:47Z

Please revert the change to this file.

stuartmorgan-g · 2026-09-09T14:11:18Z

+// ignore_for_file: avoid_print
+// ignore_for_file: omit_local_variable_types
+// ignore_for_file: strict_raw_type
+// ignore_for_file: prefer_final_locals


Why have you disabled core style rules? We have a consistent style for a reason.

stuartmorgan-g · 2026-09-15T13:33:01Z

Thanks for the contribution, but since #40 has passed review, closing in favor of that PR.

Replaces the hand-written Dart snippets in `mustache_template`'s README with `<?code-excerpt?>` pragmas backed by a new `example/lib/readme_excerpts.dart`, so every snippet is validated against compilable, analyzed source instead of free-hand text (`dart pub global run flutter_plugin_tools update-excerpts` / `validate` both pass clean). This surfaced two pre-existing doc bugs: - `Template('{{# foo }}')` in the first lambda example had no closing tag, so it threw a parse error the moment it was actually executed. - The two `<b>PUB</b>` lambda examples were an exact copy-pasted duplicate; the duplicate is removed. Also removes `ci_config.yaml`, whose only purpose was opting the package out of excerpt validation (see #102679-style TODO in the file) — no longer needed now that the README is excerpt-backed. **Note on overlap:** flutter/flutter#183936 already has two other open PRs addressing it — #23 and #36. This PR was written independently and additionally removes the `ci_config.yaml` exemption, which neither of those does. Happy to have maintainers close this in favor of one of those if that's preferred; flagging here so reviewer time isn't wasted on duplicate review. Fixes flutter/flutter#183936 ## Pre-Review Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [x] I read the [Tree Hygiene] page, which explains my responsibilities. - [x] I read and followed the [Flutter style guide] and ran [the auto-formatter]. - [x] I signed the [CLA]. - [x] The title of the PR starts with the name of the package surrounded by square brackets, e.g. `[vector_math]` - [x] I [linked to at least one issue that this PR fixes] in the description above. - [x] I followed [the version and CHANGELOG instructions], using [semantic versioning] and the [repository CHANGELOG style], or I have commented below to indicate which documented exception this PR falls under[^1]. - [x] I updated/added any relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or I have commented below to indicate which [test exemption] this PR falls under[^1]. - [x] All existing and new tests are passing. This PR only touches the README, CHANGELOG, an example app, and a CI opt-out file — no package source changed, so it falls under the documentation/example test exemption. The new `example/lib/readme_excerpts.dart` is exercised directly (`dart run`) as part of verifying this change, and every existing test in the package (`dart test`, 252 tests) still passes. [^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.  [Contributor Guide]: https://github.com/flutter/core-packages/blob/main/CONTRIBUTING.md [AI contribution guidelines]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines [Tree Hygiene]: https://github.com/flutter/flutter/blob/master/docs/contributing/Tree-hygiene.md [Flutter style guide]: https://github.com/flutter/flutter/blob/master/docs/contributing/Style-guide-for-Flutter-repo.md [the auto-formatter]: https://github.com/flutter/packages/blob/main/script/tool/README.md#format-code [CLA]: https://cla.developers.google.com/ [linked to at least one issue that this PR fixes]: https://github.com/flutter/flutter/blob/master/docs/contributing/Tree-hygiene.md#overview [the version and CHANGELOG instructions]: https://github.com/flutter/flutter/blob/master/docs/ecosystem/contributing/README.md#version-and-changelog-updates [semantic versioning]: https://dart.dev/tools/pub/versioning#semantic-versions [repository CHANGELOG style]: https://github.com/flutter/flutter/blob/master/docs/ecosystem/contributing/README.md#changelog-style [test exemption]: https://github.com/flutter/flutter/blob/master/docs/contributing/Tree-hygiene.md#tests FPOCTSMP-8

princesoni18 added 4 commits August 2, 2026 00:35

Add example app and code excerpts for mustache_template

eeb1b88

Fix unclosed mustache tag in lambda example

97bb613

Add docstrings to example app functions

4f8e4ac

Update mustache template example with improved string handling

98925c5

github-actions Bot added the p: mustache_template label Aug 2, 2026

gemini-code-assist Bot reviewed Aug 2, 2026

View reviewed changes

Comment thread third_party/packages/mustache_template/README.md Outdated

Comment thread third_party/packages/mustache_template/README.md Outdated

Comment thread third_party/packages/mustache_template/README.md Outdated

Sync README excerpts with updated main.dart

2bb2389

princesoni18 mentioned this pull request Aug 2, 2026

[mustache_template] No example app flutter/flutter#183936

Closed

stuartmorgan-g self-requested a review August 3, 2026 15:44

stuartmorgan-g requested changes Aug 3, 2026

View reviewed changes

Address code review feedback for example app

5633d58

Restructure examples into readme_excerpts.dart

3924d65

princesoni18 added 3 commits August 8, 2026 15:11

Finalize README excerpts to match repo standard

cc69780

Fix omit_obvious_local_variable_types lint in example app

56a54b8

Fix additional omit/specify local variable types lints in example

4102b90

Merge branch 'main' into add-mustache-template-example

534b7ad

DaNiELChIoRo mentioned this pull request Aug 31, 2026

[mustache_template] Adopt code-excerpts for README #39

Closed

11 tasks

danielleon-cmd mentioned this pull request Aug 31, 2026

[mustache_template] Adopt code-excerpts for README #40

Merged

11 tasks

stuartmorgan-g requested changes Sep 9, 2026

View reviewed changes

stuartmorgan-g closed this Sep 15, 2026


		## Example usage

		<?code-excerpt "main.dart (example_usage)"?>

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princesoni18 commented Aug 2, 2026

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princesoni18 commented Aug 5, 2026

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stuartmorgan-g commented Sep 15, 2026

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