Migrate Groovy To Java Skill for Claude

Migrate test Groovy files to Java using JUnit 5

• List all Groovy files of the current Gradle module
• Convert Groovy files to Java using JUnit 5
• Make sure the tests are still passing after migration and that the test count has not changed
• Remove Groovy files

When converting Groovy code to Java code, make sure that:

• The Java code generated is compatible with JDK 8
• When translating Spock tests, prefer @TableTest for data rows that are naturally tabular. See detailed guidance in the "TableTest usage" section.
• @TableTest and @MethodSource may be combined on the same @ParameterizedTest when most cases are tabular but a few cases require programmatic setup.
• In combined mode, keep table-friendly cases in @TableTest, and put only non-tabular/complex cases in @MethodSource.
• If @TableTest is not viable for the test at all, use @MethodSource only.
• If @TableTest was successfully used and if the @ParameterizedTest is not used to specify the test name, @ParameterizedTest can then be removed as @TableTest replace it fully.
• For @MethodSource, name the arguments method <testMethodName>Arguments (camelCase, e.g. testMethodArguments) and return Stream<Arguments> using Stream.of(...) and arguments(...) with static import.
• Ensure parameterized test names are human-readable (i.e. no hashcodes); instead add a description string as the first Arguments.arguments(...) value or index the test case
• When converting tuples, create a light dedicated structure instead to keep the typing system
• Instead of checking a state and throwing an exception, use JUnit asserts
• Instead of using assertTrue(a.equals(b)) or assertFalse(a.equals(b)), use assertEquals(expected, actual) and assertNotEquals(unexpected, actual)
• Import frequently used types rather than using fully-qualified names inline, to improve readability
• Do not wrap checked exceptions and throw a Runtime exception; prefer adding a throws clause at method declaration
• Do not mark local variables final
• Ensure variables are human-readable; avoid single-letter names and pre-define variables that are referenced multiple times
• When translating Spock Mock(...) usage, use libs.bundles.mockito instead of writing manual recording/stub implementations
• Replace injectSysConfig(key, value) calls with @WithConfig when the key and value are static literals. Put it on the test method for per-test config, or on the class when every test needs it. The dd. prefix is added automatically — use the bare key (e.g. "trace.scope.strict.mode", not "dd.trace.scope.strict.mode"). For dynamic or parameterized values, keep the imperative WithConfigExtension.injectSysConfig(key, value) call.
• Keep inline comments
• Migrate the named Spock clauses if they exist as inline comments in the Java unit test
• When Groovy tests navigate a JSON request body through helpers like asMap() / asLong() / asList(), check whether json-unit-assertj (libs.json.unit.assertj) is already in the module's build file. If it is, add a method that returns the raw JSON string and use assertThatJson(json).node("some.nested.field").isEqualTo(value) directly instead of the map traversal.
• Groovy's [key: val] map literals use a LinkedHashMap. When the test doesn't care about insertion order, use singletonMap for a single entry or HashMap for two or more. If a helper method builds these maps, add a two-arg overload rather than scattering new LinkedHashMap<>() constructions through test bodies.

TableTest usage

Import: import org.tabletest.junit.TableTest;

JDK 8 rules:

• No text blocks.
• @TableTest must use String[] annotation array syntax:

    @TableTest({
      "a | b",
      "1 | 2"
    })

Spock where: → @TableTest:

• First row = header (column names = method parameters).
• Add scenario column as first column (display name, not a method parameter).
• Use | delimiter; align columns so pipes line up vertically.
• Prefer single quotes for strings with special chars (e.g., 'a|b', '[]').
• Blank cell = null (object types); '' = empty string.
• Collections: [a, b] = List/array, {a, b} = Set, [k: v] = Map.

Mixed eligibility:

• Prefer combining @TableTest + @MethodSource on one @ParameterizedTest when only some cases are complex.
• Use @MethodSource only when tabular representation is not practical for the test.

Do NOT use @TableTest when:

• Majority of rows require complex objects or custom converters.

Quality rules (apply during generation)

Before writing any Java output, read .claude/skills/migrate-groovy-to-java/QUALITY_RULES.md in full.

Apply all BLOCKER rules unconditionally.

Apply WARNING rules unless they require creating utility classes that do not yet exist.

Apply STYLE rules where they improve clarity without added complexity.