asmhatreandClaude Sonnet 5
bfc67986bc
Companion code for the rewritten post "Organising and Displaying JUnit Tests: @DisplayName, @Nested, @Tag (JUnit 5 -> JUnit 6)". Same suite also runs green on JUnit 5.14.4 via -Djunit.version. Verified, not assumed: GA dates and versions cross-checked against Maven Central metadata and docs.junit.org release notes; the @TestMethodOrder-inheritance-into-@Nested-classes and MethodOrderer.Default/ClassOrderer.Default behaviour differences between 5.14.4 and 6.1.3 are demonstrated by actually running the same source under both engines (see organising/output/12-* and 14-*), not by reading about them. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01YXCrLgRKFgCh9RHKW8xaqJ
Organising and Displaying JUnit Tests - DisplayNameGenerator, @Nested, @Tag
Runnable companion to the ankurm.com article "Organising and Displaying JUnit Tests: @DisplayName,
@Nested, @Tag (JUnit 5 to JUnit 6)". Every scenario is a small fixture driven through the real
JUnit Platform Launcher (see RunHelper.java); the tests assert on what actually happened and
write it to output/, so every transcript quoted in the article is also an assertion that fails
the build the day it stops being true.
Versions
| Item | Version |
|---|---|
JUnit (default, junit.version) |
6.1.3 (Jupiter, Platform, Launcher - single version line since 6.0) |
| Also run green on | 5.14.4 (mvn test -Djunit.version=5.14.4) |
| JUnit 6.0.0 GA date | September 30, 2025 (confirmed on docs.junit.org/current/release-notes) |
| Java | 17 language level (maven.compiler.release), run on JDK 25.0.4.1 (Temurin, current LTS) |
| Maven Surefire | 3.5.4 |
Both GA numbers were cross-checked against maven-metadata.xml on Maven Central
(org/junit/platform/junit-platform-commons and org/junit/junit-bom), not against a blog or an
LLM's memory - see the article's versions callout.
What each scenario demonstrates
| Class | Shows | Output |
|---|---|---|
DisplayNameFixtures.PlainDefault |
the default Standard generator - raw method signature |
01-default-generator.txt |
DisplayNameFixtures.Underscored |
DisplayNameGenerator.ReplaceUnderscores |
02-replace-underscores.txt |
DisplayNameFixtures.Sentences |
DisplayNameGenerator.IndicativeSentences joining class + nested + method into one sentence |
03-indicative-sentences.txt |
DisplayNameFixtures.CustomSentenceCase + SentenceCaseGenerator |
a hand-written DisplayNameGenerator |
04-custom-generator.txt |
DisplayNameFixtures.ConfiguredByDefault |
setting the generator project-wide via junit.jupiter.displayname.generator.default, no annotation touched |
05-no-config-param.txt, 06-configured-default-generator.txt |
LoanDeskTest |
@DisplayNameGeneration + @Nested + @Tag used together, tag inheritance into nested and doubly-nested classes |
real mvn test run, 17-mvn-cli-tag-filter.txt |
TagFixtures.CatalogServiceTest |
include/exclude filtering, composed tag annotations, OR-vs-AND semantics of TagFilter.includeTags |
07, 08, 09, 09b |
TagFixtures.TrimmedTagClass |
leading/trailing whitespace in a tag is silently trimmed, not invalid | 10, 10b |
TagFixtures.InternalWhitespaceTagClass |
internal whitespace is invalid - logged as a non-critical discovery warning and the tag is dropped, test still runs | 10c, 10d |
TagFixtures.BlankTagClass |
an empty @Tag("") inside @Tags is dropped the same way |
11 |
OrderingFixtures.DefaultSiblingOrder |
sibling @Nested class order with no orderer declared - deterministic, but a different order on 5.14.4 vs 6.1.3 |
12-*-run1/2/3.txt (stability within a version), 12-*-junit5.14.4.txt (cross-version diff) |
OrderingFixtures.ClassOrderOuter |
@TestClassOrder reaching two levels of @Nested nesting - identical on both versions in this repo's testing |
13-class-order-two-levels.txt |
OrderingFixtures.MethodOrderInheritanceOuter |
@TestMethodOrder on an outer class now cascading into an unannotated @Nested child - new in JUnit 6.0, confirmed by a different real method order on 5.14.4 |
14-method-order-inheritance*.txt |
src/broken/MethodOrdererDefaultDemo.java |
MethodOrderer.Default / ClassOrderer.Default (opt a @Nested class back out of inherited ordering) added in 6.0 - compiles on 6.1.3, fails on 5.14.4 |
15, 16 |
Prerequisites
- JDK 17 or higher (built and run here on JDK 25.0.4.1)
- Maven 3.6+
How to run
mvn test # full suite, JUnit 6.1.3
mvn test -Djunit.version=5.14.4 # same suite, JUnit 5.14.4
mvn test -Dgroups=fast # only @Tag("fast") tests
mvn test -DexcludedGroups=slow # everything except @Tag("slow")
scripts/run-all.sh regenerates every file in output/ from a clean state in one command,
including the cross-version comparison files and the src/broken compiler-message transcripts.
Instance ordering in 12-nested-sibling-order-*.txt is stable within one JUnit version but is
explicitly NOT something to hand-derive - it is only ever read from a real run.