[andrewkolos]

CI resolves the Dart packages from source through the pub workspace, so it passes while the versions on pub.dev cannot be used together (#3942). This adds a check to pull requests that change a2ui_core's version.

For every other package under dart/ that constrains a2ui_core and is on pub.dev, the check fails unless the pull request releases that package too, or the latest version on pub.dev already accepts the new a2ui_core. The pull request releases a package when it changes the package's version: or the top heading of its CHANGELOG.md, leaves the two equal, and the version would become the latest on pub.dev. Packages that are not on pub.dev, such as a2ui_cli, are skipped. The failure message points at the release steps that #3973 adds.

Replayed on the last two a2ui_core releases, #3192 and #3695, it fails both, naming a2ui_agent. On #3695:

a2ui_core 0.3.0 -> 0.4.0
a2ui_cli: not on pub.dev, skipped
a2ui_flutter 0.0.1-wip003 on pub.dev accepts a2ui_core 0.4.0
error: a2ui_agent 0.0.1-wip004, the latest version on pub.dev, requires a2ui_core ^0.2.2, which excludes 0.4.0, and this pull request does not release a2ui_agent: this pull request changes neither its version (0.0.1-wip005) nor the top heading of its CHANGELOG.md. Release a2ui_agent in this pull request, as docs/contributing/release/release.md describes.

Part of #3945. The scheduled check that installs the published packages together comes after the next Dart release, since it fails until then.

Pre-launch Checklist

One time:

• I signed the CLA.
• I read the Contributors Guide.
• I read the Style Guide.
• I have built and run at least one sample.

For this PR:

• I have updated the relevant CHANGELOG.md file.
• I updated/added relevant documentation.
• My code changes (if any) have tests.
• If my branch is on a fork, I have verified that scripts/e2e_test.sh passes.

_{ℹ️ Initial text drafted by agent}

[gemini-code-assist]

Code Review

This pull request introduces a new Python script, check_dart_dependents.py, along with its test suite, to ensure that Dart package releases do not leave dependent packages on pub.dev incompatible. The feedback highlights a critical bug in the version constraint resolution logic: caret constraints on 0.0.x versions (where both major and minor are 0) are incorrectly treated like 0.y.z versions. In Dart's pub package manager, ^0.0.x should only allow that exact patch version. Suggestions are provided to correct this logic in the script and update the corresponding test assertions to reflect the proper behavior.

[gemini-code-assist]

In Dart's pub package manager, caret constraints on 0.0.x versions (where both major and minor are 0) behave differently than other 0.y.z versions. Specifically, ^0.0.x is equivalent to >=0.0.x <0.0.(x+1), meaning it only allows that exact patch version (and its prereleases), rather than stopping at the next minor version 0.1.0.

Currently, the implementation treats ^0.0.x the same as ^0.y.z and sets the upper bound to 0.1.0, which incorrectly allows incompatible patch versions (e.g., treating ^0.0.3 as allowing 0.0.4). Updating this to correctly increment the patch version when both major and minor are 0 ensures alignment with Dart's version resolution rules.

Suggested change

	if start.major > 0:
	end = Version(start.major + 1, 0, 0)
	else:
	end = Version(0, start.minor + 1, 0)
	if start.major > 0:
	end = Version(start.major + 1, 0, 0)
	elif start.minor > 0:
	end = Version(0, start.minor + 1, 0)
	else:
	end = Version(0, 0, start.patch + 1)

[gemini-code-assist]

Update the test assertions to reflect the correct Dart pub caret constraint behavior for 0.0.x versions. Since ^0.0.3 is equivalent to >=0.0.3 <0.0.4, it should not allow 0.0.4. Similarly, ^0.0.1-wip002 should not allow 0.0.2.

Suggested change

	def test_caret_on_zero_minor_also_stops_at_next_minor(self):
	self.assertTrue(cdd.allows("^0.0.3", V("0.0.4")))
	self.assertTrue(cdd.allows("^0.0.1-wip002", V("0.0.2")))
	self.assertFalse(cdd.allows("^0.0.3", V("0.1.0-0")))
	self.assertFalse(cdd.allows("^0.0.3", V("0.1.0")))
	def test_caret_on_zero_major_and_minor_stops_at_next_patch(self):
	self.assertFalse(cdd.allows("^0.0.3", V("0.0.4")))
	self.assertFalse(cdd.allows("^0.0.1-wip002", V("0.0.2")))
	self.assertTrue(cdd.allows("^0.0.3", V("0.0.3")))