Always use appropriate assertion methods in tests to ensure proper verification of command behavior. When you don't need to examine command output, use `.success()` to verify the command completed without errors. When the output content is meaningful for testing the functionality, capture and snapshot it for verification. **Problematic approach:** ```rust // Ignoring output when we should verify success let _output = test_env.run_jj_in(&workspace_root, ["git", "colocation", "enable"]); // Using .success() when output should be verified work_dir.run_jj(["metaedit", "--author-timestamp", "2001-02-03 04:05:14.000+07:00"]).success(); ``` **Better approach:** ```rust // Use .success() when only caring about command completion test_env.run_jj_in(&workspace_root, ["git", "colocation", "enable"]).success(); // Snapshot output when it's meaningful for verification let output = work_dir.run_jj(["metaedit", "--author-timestamp", "2001-02-03 04:05:14.000+07:00"]); insta::assert_snapshot!(output, @"..."); ``` This practice ensures that tests properly verify both command success and expected behavior, making test failures more informative and catching regressions in command output or error handling.