Run Tests

Gotchas

• Never call two Unity Editor tools in parallel. mcp__jetbrains__unity_play_control, mcp__jetbrains__get_unity_compilation_result, mcp__jetbrains__run_unity_tests, and mcp__jetbrains__run_method_in_unity must be called strictly one at a time — always wait for each call to return before making the next one. Calling them concurrently causes domain-reload conflicts that result in "canceled" or "did not connect within 30 seconds" errors.
• When a Unity Editor tool returns error or canceled, wait 10 seconds before retrying. Domain reload typically takes several seconds; immediate retry hits the same in-flight reload and fails again. Do not switch tools in the meantime (e.g., calling mcp__jetbrains__unity_play_control to verify state) — that just compounds the multiplexed calls. If the same tool returns error or canceled on two consecutive attempts (with the 10-second wait between them), stop and consult the user instead of retrying further.

Run Tests

Before running tests, complete the following steps in order:

1. If any code was modified, confirm compilation success using the mcp__jetbrains__get_unity_compilation_result tool before proceeding.
2. To determine assemblyNames and testMode for a specific test class, run ${CLAUDE_SKILL_DIR}/scripts/resolve-test-target.sh . The script prints \t (e.g. MyGame.Tests\tPlayMode). Skip this step when running an already-known assembly.

Then use the mcp__jetbrains__run_unity_tests tool to run the tests on the Unity editor.

Test execution can take several minutes. Do not re-run while a test is in progress — always wait for it to complete or time out. If a timeout occurs, narrow down the tests using filter settings and re-run.

Rules for Test Failures

If the same test(s) fail on two or more consecutive runs, stop and consult the user rather than continuing to fix.

When consulting, clarify:

• Current failure status: what is failing and the likely cause
• Fix history: what was changed, how many times, and the scope of impact
• Planned approach: what options are being considered next

Troubleshooting

Read the appropriate resource file based on the situation:

• Any Unity MCP tool (mcp__jetbrains__run_unity_tests, mcp__jetbrains__unity_play_control, mcp__jetbrains__get_unity_compilation_result) is not available or fails with a connection error: Read ${CLAUDE_SKILL_DIR}/resources/troubleshooting-run-unity-tests.md
• A test fails due to an assertion, constraint, or comparer in the TestHelper namespace (excluding TestHelper.UI): Read ${CLAUDE_SKILL_DIR}/resources/troubleshooting-test-helper.md
• A test fails due to an exception thrown from the TestHelper.UI namespace: Read ${CLAUDE_SKILL_DIR}/resources/troubleshooting-test-helper-ui.md

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: nowsprinting
• Source: nowsprinting/unity-coding-skills
• License: Unlicense

Install and usage instructions live in the source repository linked above.