Test: Split tests by tag

[qligier]

This is an attempt at optimizing the memory consumption of tests by grouping related tests, and running JUnit once per group.

[Copilot]

Pull request overview

This PR introduces JUnit 5 tags to split the test suite into logical groups and updates the GitHub Actions Maven workflow to run each group in a separate Maven invocation, aiming to reduce peak memory usage during CI test runs.

Changes:

• Added a TestTags constants class and annotated tests with @Tag(...) to group them (core/validation/gazelle/mapping).
• Updated multiple matchbox-server test classes to use tags (and cleaned up some visibility/imports).
• Changed .github/workflows/maven.yml to run Maven tests once per group instead of a single full verify.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
matchbox-server/src/test/java/ch/ahdis/matchbox/test/MatchboxApiR5onR4Test.java	Adds JUnit tags to split tests into groups.
matchbox-server/src/test/java/ch/ahdis/matchbox/test/MatchboxApiR5Test.java	Adds JUnit tags and removes some unused imports.
matchbox-server/src/test/java/ch/ahdis/matchbox/test/MatchboxApiR4Test.java	Tags individual tests into validation/core/gazelle groups.
matchbox-server/src/test/java/ch/ahdis/matchbox/test/MatchboxApiR4BTest.java	Adds JUnit tags to split tests into groups.
matchbox-server/src/test/java/ch/ahdis/matchbox/mapping/TransformTest.java	Tags the whole class as mapping-related.
matchbox-server/src/test/java/ch/ahdis/matchbox/gazelle/GazelleApiR4Test.java	Tags the whole class as gazelle-related.
matchbox-server/src/test/java/ch/ahdis/matchbox/TestTags.java	Introduces shared tag constants for tests.
.github/workflows/maven.yml	Runs Maven tests four times, one per group/tag.

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[Copilot]

The workflow now runs only the test phase. Previously it ran verify, which also executes any verify-bound checks (e.g., duplicate-finder) and can affect integration-test execution via failsafe. If those checks are still required in CI, switch back to verify (or add an explicit step to run the missing phases) while still filtering by tag/group.

[Copilot]

CI now runs Maven four times with -Dgroups=.... Only tests tagged into these groups will execute; currently the matchbox-engine module tests are untagged (e.g., matchbox-engine/src/test/java/ch/ahdis/matchbox/engine/tests/R4ValidationTests), so they would be skipped in all four runs. Consider either tagging engine tests too, adding an additional run for untagged tests, or restricting these grouped runs to the module(s) that actually use the tags.

Suggested change

	run: mvn --batch-mode --no-transfer-progress --update-snapshots -Dgroups='mapping' test
	run: mvn --batch-mode --no-transfer-progress --update-snapshots -Dgroups='mapping' test
	- name: Run ungrouped tests in Maven
	timeout-minutes: 15
	# We need a timeout here
	env:
	MAVEN_OPTS: -Xmx12g
	run: mvn --batch-mode --no-transfer-progress --update-snapshots test

[Copilot]

This workflow previously uploaded surefire reports and produced a test summary; those steps were removed. That makes CI failures harder to diagnose and reduces visibility into which tests failed. Consider re-adding artifact upload/test summary (potentially after each group run, or once at the end with if: always()).

Suggested change

	run: mvn --batch-mode --no-transfer-progress --update-snapshots -Dgroups='mapping' test
	run: mvn --batch-mode --no-transfer-progress --update-snapshots -Dgroups='mapping' test
	- name: Upload surefire test reports
	if: always()
	uses: actions/upload-artifact@v4
	with:
	name: surefire-reports
	path: |
	**/target/surefire-reports/**
	**/target/failsafe-reports/**
	- name: Publish test summary
	if: always()
	uses: dorny/test-reporter@v1
	with:
	name: Maven tests
	path: "**/target/surefire-reports/TEST-*.xml"
	reporter: java-junit

[Copilot]

TestTags is a constants holder and shouldn’t be instantiable. Consider making the class final and adding a private constructor to prevent accidental construction/extension.

Suggested change

	public class TestTags {
	public static final String CORE = "core";
	public static final String VALIDATION = "validation";
	public static final String GAZELLE = "gazelle";
	public static final String MAPPING = "mapping";
	public final class TestTags {
	public static final String CORE = "core";
	public static final String VALIDATION = "validation";
	public static final String GAZELLE = "gazelle";
	public static final String MAPPING = "mapping";
	private TestTags() {
	// Prevent instantiation
	}