How to Use t.Setenv for Environment Variables in Tests

Use t.Setenv(key, value) to set an environment variable for the duration of a test function, ensuring it is automatically restored afterward. This prevents test pollution and ensures isolation between tests.

func TestMyFunction(t *testing.T) {
	t.Setenv("MY_VAR", "test_value")
	// Your test code here
	val := os.Getenv("MY_VAR")
	if val != "test_value" {
		t.Errorf("expected test_value, got %s", val)
	}
}

t.Setenv temporarily changes an environment setting just for one specific test. It acts like a safety net that automatically resets the setting to its original state once the test finishes, preventing one test from accidentally breaking another.