Unit Test
Domain: Development & Internals
Motivation
Unit tests in dsh packages verify single-module behavior in isolation, often through dependency injection: dsh-native-command exposes the NativeCommandRunner type as an injectable command boundary so tests substitute a fake runner, and its path dispatch is covered by injected-runner tests.
Concrete Example
A dsh-native-command test injects a fake NativeCommandRunner, asserts the chosen argv per platform, and checks that a rejected error carries code, stdout, and stderr with the original error as cause.
Analogy
It is testing one gear by holding the shaft still with a mock.