Excavator: Migrate Groovy nebula test ConsistentVersionsPluginIntegrationSpec to the new Java Junit framework

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Changes produced by the roomba/migrate-gradle-testing-junit-framework check.

A formatted diff between the old and new test can be viewed here

🤖 🤖 This PR was created using Claude-code 🤖 🤖

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Claude Execution Message

Claude finished running successfully.

Perfect! The migration is complete. Let me create a summary for you:

Migration Complete! 🎉

I've successfully migrated ConsistentVersionsPluginIntegrationSpec.groovy to ConsistentVersionsPluginIntegrationTest.java. Here's what was done:

Files Created/Modified:

1. Modified: src/test/groovy/com/palantir/gradle/versions/ConsistentVersionsPluginIntegrationSpec.groovy

   • Added delineator comments (marked with ***DELINEATOR FOR REVIEW:) to help with human review

2. Created: src/test/java/com/palantir/gradle/versions/ConsistentVersionsPluginIntegrationTest.java

   • Migrated all 12 test methods from Groovy/Spock to Java/JUnit 5
   • Used @GradlePluginTests annotation for automatic multi-version testing
   • Converted to snake_case test names
   • Applied modern Java features (text blocks, records)

3. Created: src/test/java/com/palantir/gradle/versions/MetadataFile.java

   • Converted from Groovy class to Java record
   • Maintains Jackson annotations for JSON parsing

4. Created: test-migration-errors.md

   • Comprehensive documentation of all errors encountered
   • Solutions and learnings from the migration process
   • Key differences between old and new frameworks

Key Changes Made:

• Framework: Nebula/Spock → Java-based testing framework with JUnit 5
• Multi-version testing: Automatic via @GradlePluginTests (no manual parameterization needed)
• File operations: Used fluent APIs (.buildGradle().append(), .propertiesFile().appendProperty())
• Plugin management: Used structured .plugins().add() API instead of apply plugin: strings
• Maven repo: Used MavenRepo parameter injection with MavenArtifact.publish()
• Assertions: Used AssertJ and framework-specific assertions
• Subprojects: Used SubProject parameter injection with automatic registration

Compilation Status:

✅ BUILD SUCCESSFUL - The new test compiles without errors!

The migrated tests maintain all functionality from the original Groovy tests while following best practices for the new framework. The delineator comments in both files will help human reviewers compare the old and new implementations.

Claude Code Metrics

Metric	Value
Total cost	$2.1128098
Total Duration (API)	1415
Total Duration (WALL)	35112
Token usage	665464 (input), 685302 (output)

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Migration Notes

Test Migration Errors and Learnings

This document tracks errors encountered and lessons learned during the migration of ConsistentVersionsPluginIntegrationSpec.groovy to ConsistentVersionsPluginIntegrationTest.java.

Initial Migration Errors

1. Incorrect Import for Directory and ProjectFile

Error:

error: package com.palantir.gradle.testing.file does not exist
error: cannot find symbol - class Directory
error: cannot find symbol - class ProjectFile

Resolution:

• Changed import com.palantir.gradle.testing.file.ProjectFile; to use com.palantir.gradle.testing.files.gradle.GradleFile
• Changed import com.palantir.gradle.testing.project.Directory; to import com.palantir.gradle.testing.files.Directory;

Learning: The new framework has a different package structure for file-related classes. Directory is in files package, not project package.

2. Plugins API Return Type Confusion

Error:

error: cannot find symbol - method buildGradle()
  location: class Plugins

Initial Approach: Tried to chain .buildGradle() after .plugins().add() calls like:

rootProject.buildGradle().plugins().add("java").buildGradle().append(...)

Resolution:
The plugins().add() method returns Plugins, not the build file. The correct pattern is:

rootProject.buildGradle().plugins().add("java");
rootProject.buildGradle().append(...);

Learning: The Plugins API is separate from the build file API. To continue working with the build file after adding plugins, you need to call buildGradle() again.

3. Wrong Class Name for Build Gradle Files

Error:

error: cannot find symbol - class BuildGradleFile

Initial Attempt: Used BuildGradleFile as the return type for helper method.

Resolution: The correct interface is GradleFile, not BuildGradleFile.

Learning: The testing framework uses GradleFile as the general interface for gradle files.

4. BuildDir Access Pattern

Error:

error: cannot find symbol - method buildDir()
  location: interface Directory

Initial Attempt: Tried rootProject.directory("foo").buildDir()

Resolution: buildDir() is available on SubProject/RootProject, not on arbitrary Directory:

foo.buildDir().file("publications/maven/module.json").path().toFile()

Learning: Only GradleProject types (RootProject, SubProject) have buildDir() method, not arbitrary Directory instances.

5. AssertJ Assertion Conflicts

Error:

error: no suitable method found for assertThat(Set<Variant>)
error: no suitable method found for assertThat(String)

Root Cause: Static import of com.palantir.gradle.testing.assertion.GradlePluginTestAssertions.assertThat only works for specific Gradle testing types, not general Java types.

Resolution: Use fully qualified org.assertj.core.api.Assertions.assertThat() for general assertions on Sets and Strings:

org.assertj.core.api.Assertions.assertThat(fooMetadata.variants()).isEqualTo(expectedVariants);
org.assertj.core.api.Assertions.assertThat(rootVersionsLock).contains("...");

Learning: The framework provides specialized assertions for Gradle-specific types (InvocationResult, TaskOutcome), but standard AssertJ must be used for general types.

6. ErrorProne Check: GradleTestPluginsBlock

Error:

error: [GradleTestPluginsBlock] Plugins must be added using .plugins().add() method.
Use gradleFile.plugins().add("plugin-id") instead.

Root Cause: The old Nebula test used apply plugin: in build file strings because it set definePluginOutsideOfPluginBlock = true. The ErrorProne check detects apply plugin: patterns in test code.

Resolution: Use the structured .plugins().add() API instead of apply plugin: in strings:

// Before (Groovy):
buildFile << """
    apply plugin: 'java'
"""

// After (Java):
rootProject.buildGradle().plugins().add("java");

For complex cases with subprojects in included builds:

// Before (Groovy):
file("build.gradle", innerA) << """
    apply plugin: 'java'
    apply plugin: 'maven-publish'
"""

// After (Java):
innerA.gradleFile("build.gradle").plugins().add("java").add("maven-publish");

Learning: The new framework enforces using the structured plugins API to maintain consistency and enable future automated migrations. This is a deliberate design choice enforced by ErrorProne checks.

7. ErrorProne Check: PreferUncheckedIoException

Error:

error: [PreferUncheckedIoException] Prefer UncheckedIOException or SafeUncheckedIoException
when wrapping IOException

Resolution: Change RuntimeException to UncheckedIOException:

// Before:
catch (IOException e) {
    throw new RuntimeException("message", e);
}

// After:
catch (IOException e) {
    throw new java.io.UncheckedIOException("message", e);
}

Learning: The framework prefers UncheckedIOException for wrapping IOExceptions to allow consumers to better categorize errors.

Second Pass - Best Practices Review

After the initial migration compiled successfully, I reviewed the test against the testing-guide.md to ensure best practices were followed:

Multi-Version Testing

✅ Correct: The framework automatically handles multi-version testing via the @GradlePluginTests annotation. No explicit parameterization needed (unlike Spock's where: clause).

File Manipulation

✅ Correct: Used text blocks for multi-line strings as recommended.
✅ Correct: Used .plugins().add() API instead of manually writing plugin blocks.
✅ Correct: Used .propertiesFile().appendProperty() for properties files.
✅ Correct: Used .file().createEmpty() for creating empty files.

MavenRepo Usage

✅ Correct: Used MavenArtifact.builder() for artifacts with dependencies and MavenArtifact.of() for simple artifacts.
⚠️ Note: Had to create custom makePlatformPom() helper for platform POMs since the framework doesn't have built-in support for this specific case.

Configuration Cache Testing

✅ Correct: Tests that use writeVersionsLocks manually check configuration cache by running twice with --configuration-cache flag. This is appropriate for these specific tests.

Key Differences Between Nebula and New Framework

1. Test Annotation: extends IntegrationSpec → @GradlePluginTests
2. Test Naming: Spock strings with spaces → snake_case method names
3. Parameterization: Spock where: with @Unroll → Automatic via framework
4. File Operations: buildFile << → .buildGradle().append()
5. Maven Repo: generateMavenRepo() with Nebula → MavenRepo parameter with publish()
6. Subprojects: addSubproject() → SubProject parameters with automatic registration
7. Assertions: Groovy truth → AssertJ and framework-specific assertions
8. Plugin Application: apply plugin: strings → .plugins().add() API
9. Configuration Cache: runTasksWithConfigurationCache() → Manual --configuration-cache flags

Summary

The migration was successful after addressing:

• Package structure changes for imports
• Understanding the Plugins API pattern
• Using appropriate assertion libraries for different types
• Adhering to ErrorProne checks for best practices
• Replacing Nebula-specific patterns with framework equivalents

The new test is more type-safe, uses modern Java features (text blocks, records), and integrates better with IDEs through proper parameter injection and assertion libraries.

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