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Yoko Interoperability Testing

Overview

Yoko includes infrastructure for testing interoperability between different versions of Yoko. This allows you to verify that the current development version can communicate correctly with earlier released versions.

Quick Start

1. Build or Fetch a Yoko Version

Before running interop tests, you need to cache the Yoko version you want to test against. You have two options:

Option A: Fetch from GitHub releases (faster)

./gradlew fetchYokoVersion -PyokoVersion=1.5.3

This downloads the release JARs from GitHub using the gh CLI and caches them in ~/.yoko-interop-cache/<version>/.

Option B: Build from source

./gradlew buildYokoVersion -PyokoVersion=1.5.3

This creates a git worktree, builds the specified version from source, and caches all JARs in ~/.yoko-interop-cache/<version>/.

If this step is omitted, any tests relying on this version will be skipped.

2. Write an Interop Test

Use @InteropTest to mark tests that require a specific Yoko version:

@InteropTest(V1_5_3)
public class MyInteropTest {
    public interface MyService extends Remote {
        Object echo(Object o);
    }

    @RemoteImpl
    static MyService serviceImpl = o -> o;

    @Test
    void testCompatibility(MyService stub) {
        // Test logic here
    }
}

The @InteropTest annotation automatically: - Tags the test with @Tag("interop") for selective execution - Configures @ConfigureServer(separation = INTER_PROCESS) - Sets up the server to run with the specified Yoko version

Gradle Tasks

# Fetch and cache a version from GitHub releases (requires gh CLI)
./gradlew fetchYokoVersion -PyokoVersion=1.5.3

# Build and cache a version from source
./gradlew buildYokoVersion -PyokoVersion=1.5.3

# List cached versions
./gradlew listCachedYokoVersions

# Clean cached JARs only
./gradlew cleanYokoCache

# Clean worktrees only
./gradlew cleanYokoWorktrees

# Clean both JARs and worktrees
./gradlew cleanCachedYokoVersions

Cache Locations

  • JARs: ~/.yoko-interop-cache/<version>/
  • Worktrees: <project-root>/worktrees/<version>/

Key Constraints

  • @InteropTest automatically configures separation = INTER_PROCESS
  • Tests are tagged with @Tag("interop") and can be excluded in CI builds
  • Tests automatically skip if the version isn't cached (using JUnit assumptions)
  • Server runs with the specified version; client always uses current development version