Introduce a health checking workflow

[mosuem]

Merging #114 and #113 together with package validation to produce a single workflow.

It needs to be determined how this should behave w.r.t. publishing - do we want to keep a separate workflow for that? Should this be an argument to the health.yaml workflow?

---

• I’ve reviewed the contributor guide and applied the relevant portions to this PR.

Contribution guidelines:

• See our contributor guide for general expectations for PRs.
• Larger or significant changes should be discussed in an issue before creating a PR.
• Contributions to our repos should follow the Dart style guide and use dart format.
• Most changes should add an entry to the changelog and may need to rev the pubspec package version.
• Changes to packages require corresponding tests.

Note that many Dart repos have a weekly cadence for reviewing PRs - please allow for some latency before initial review feedback.

[github-actions]

PR Health

License Headers ✔️

Details

Some .dart files were found to not have license headers. Please add the following header to all listed files:

// Copyright (c) 2023, 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

Either manually or by running the following in your repository directory

dart pub global activate --source git https://github.com/mosuem/file_licenser
dart pub global run file_licenser .

Changelog entry ✔️

Details

Changes to these files need to be accounted for in their respective changelogs:

Package	Files

[devoncarew]

Some thoughts apart from what's in-line:

• I think it's worth having a 'health' check separate from the publishing one
• that's a good check to group a bunch a disparate items (changelog, copyright, ...)

[devoncarew]

@jonasfj - I remember that you were thinking of adding the ability to run packages directly (the context I remember this from was the flutter project template one). Something like dart pub run <package>:<tool> would just run that tool w/o having to activate it locally first.

[devoncarew]

Bikeshedding on other possible PR comments:

---

Licenses

☑️	File
❌	pkgs/firehose/test/new_test.dart

All source files should start with a license header.

Changelogs

☑️	Package	Changed Files
❌	package:firehose	pkgs/firehose/bin/firehose.dart, pkgs/firehose/lib/firehose.dart, pkgs/firehose/lib/src/github.dart, pkgs/firehose/pubspec.yaml, pkgs/firehose/test/new_test.dart

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