build: per-module test execution via tycho-build extension (PoC)

[joaodinissf]

Note

Stacked on #1283. The bottom commit is #1283 (build: enable UI tests on macOS via Tycho profile + JRE docs). This PR contains 3 additional commits on top. CI failures here until #1283 lands are expected; rebase onto master once #1283 merges.

Summary

Proof of concept demonstrating that per-module Maven test execution is viable for this codebase via two changes:

1. Register tycho-build as a Maven core extension so -am walks OSGi Require-Bundle / Import-Package dependencies (Maven natively only walks <dependency> blocks, which are empty for Tycho bundles).
2. Add an opt-in property gate (ddk.skipPerModuleTests, default true) for per-module surefire blocks, so that opting modules in does not double-execute tests already discovered by the aggregator in com.avaloq.tools.ddk.xtext.test.

The PoC pilots the pattern on com.avaloq.tools.ddk.xtext.export.test (smallest blast radius). After this lands, the same shape can be applied to other *.test modules on demand.

Commits

1. build: add tycho-build extension — .mvn/extensions.xml + .mvn/maven.config. Version sourced from ${tycho.version} to keep a single source of truth.
2. build: add ddk.skipPerModuleTests property — declares the property in ddk-parent. No behaviour change yet.
3. build: opt xtext.export.test into per-module test execution — adds full tycho-surefire-plugin + target-platform-configuration to the bundle, gated by the property. <testClass> points at ExportTestSuite. Mirrors xtext.test's surefire block, with one extra argLine flag (-Dorg.osgi.framework.system.packages.extra=jdk.incubator.vector) needed on macOS for org.eclipse.help.base to resolve.

Verification (run on this branch, JDK 21, macOS aarch64)

#	Scenario	Command	Result
B	Cold sanity (tycho-build extension)	find . -name target -type d -exec rm -rf {} + ; mvn -pl :check.core -am -DskipTests clean verify	✅ Reactor expanded from 1 project (without extension) to 12 projects (with extension), BUILD SUCCESS cold
C	Focused dev — standalone tests with override	mvn verify -pl :xtext.export.test -am -Dddk.skipPerModuleTests=false	✅ Reactor 17 projects; Tests run: 14, Failures: 0; 21.2s wall clock
D	Default behaviour — gate skips standalone	mvn verify -pl :xtext.export.test -am (default property=true)	✅ [INFO] Skipping tests logged; export.test packaged in 1.0s (vs 7.0s when tests ran)
E	Full-reactor double-execution proof	mvn verify -Dddk.skipPerModuleTests=false (full 60-project reactor)	✅ 371 tests run (357 aggregator + 14 standalone), two distinct surefire summaries, exit code 0, 1m30s total wall clock

Empirical findings worth highlighting

• Wall-clock is fast. Full reactor with property flipped (every dependency built + aggregator + standalone) completes in 1m30s on an M-series Mac. The aggregator alone consumes 1m05s of that. The 30-minute timeout in AGENTS.md reflects pessimism, not measured behaviour.
• Double-execution is exactly as predicted. Two surefire summaries land in the log: Tests run: 14 (standalone) and Tests run: 357 (aggregator). 357 matches the baseline test count on master (CI run on d6897f240). The 14 extra are the export tests running a second time as standalone — confirming the gate's intent.
• Cost of opt-in (when enabled): an extra ~7 seconds of test execution + Eclipse runtime startup for export.test. Trivial. Most of the standalone runtime cost is amortized into reactor build steps that happen anyway.
• The PoC is gated on build: enable UI tests on macOS via Tycho profile + JRE docs #1283. Without build: enable UI tests on macOS via Tycho profile + JRE docs #1283's macosx Maven profile, the standalone test runtime fetches SWT-win32 (target environments default to win32/win32/x86_64), which can't load on macOS → ClassNotFoundException: org.eclipse.swt.SWTError. With build: enable UI tests on macOS via Tycho profile + JRE docs #1283's macosx profile (sets osgi.os=macosx, osgi.ws=cocoa, osgi.arch=aarch64 and appends -XstartOnFirstThread), the issue resolves cleanly. Documented as the stack dependency above.
• The Lucene/jdk.incubator.vector cascade affects Maven surefire too, not just .launch files. Same root cause as the existing open work; same fix (-Dorg.osgi.framework.system.packages.extra=jdk.incubator.vector). The aggregator likely has the same latent issue on macOS but no one runs it via plain mvn verify on Mac normally — CI is Linux, which doesn't trigger it. A broader fix is open as a follow-up.
• Required environment for standalone Mac runs: JAVA_HOME pointing to JDK 21 (project's BREE — openjdk@21 on Homebrew; the default openjdk is 25 and has separate sun.misc.Unsafe issues), and WORKSPACE=$(pwd) (needed by the logback config path in ddk-parent).

Usage

CI (unchanged):

mvn verify -f ./ddk-parent/pom.xml

Focused dev iteration on export tests only:

export WORKSPACE=\$(pwd)
mvn verify -pl :com.avaloq.tools.ddk.xtext.export.test -am \\
           -Dddk.skipPerModuleTests=false -f ./ddk-parent/pom.xml

Known limitation

tycho-build is incompatible with mvnd — the embedded Takari SmartBuilder collides with tycho-build's dependency graph (DependencyGraph ClassCastException across ClassRealms, independent of -b flag). Use plain mvn for -am workflows; mvnd remains usable for full-reactor builds without -am.

Test plan

• CI runs mvn verify (default property) and aggregator tests pass without regression (357 tests, same as master baseline). Validates Scenario D under full CI load.
• CI runs mvn verify -pl :com.avaloq.tools.ddk.xtext.export.test -am -Dddk.skipPerModuleTests=false and 14 export tests pass standalone. Validates Scenario C on Linux.
• Once green: rebase onto master after build: enable UI tests on macOS via Tycho profile + JRE docs #1283 merges; verify both scenarios still pass.

Left by Claude at João's request.