Improve error handling and diagnostics for the audita subprocess

internal/adapters/subprocess/run_test.go

@@ -109,6 +109,67 @@ func TestRunTimeout(t *testing.T) {
 	}
 }
 
+func TestRunInheritsParentEnvironmentByDefault(t *testing.T) {
+	exe, err := os.Executable()
+	if err != nil {
+		t.Fatalf("os.Executable() error = %v", err)
+	}
+
+	t.Setenv("GO_WANT_SUBPROCESS_HELPER", "1")
+	t.Setenv("SUBPROCESS_HELPER_ENV_KEY", "SUBPROCESS_PARENT_VALUE")
+	t.Setenv("SUBPROCESS_PARENT_VALUE", "inherited-value")
+
+	dir := t.TempDir()
+	stdoutPath := filepath.Join(dir, "stdout.log")
+	req := RunRequest{
+		Executable:    exe,
+		Args:          []string{"-test.run=TestSubprocessHelper", "--", "printenv"},
+		StdoutLogPath: stdoutPath,
+	}
+
+	if _, err := Run(context.Background(), req); err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+	data, err := os.ReadFile(stdoutPath)
+	if err != nil {
+		t.Fatalf("read stdout log: %v", err)
+	}
+	if strings.TrimSpace(string(data)) != "inherited-value" {
+		t.Fatalf("stdout = %q, want inherited-value", strings.TrimSpace(string(data)))
+	}
+}
+
+func TestRunEnvOverridesWinOverInheritedValues(t *testing.T) {
+	exe, err := os.Executable()
+	if err != nil {
+		t.Fatalf("os.Executable() error = %v", err)
+	}
+
+	t.Setenv("GO_WANT_SUBPROCESS_HELPER", "1")
+	t.Setenv("SUBPROCESS_HELPER_ENV_KEY", "SUBPROCESS_PARENT_VALUE")
+	t.Setenv("SUBPROCESS_PARENT_VALUE", "parent-value")
+
+	dir := t.TempDir()
+	stdoutPath := filepath.Join(dir, "stdout.log")
+	req := RunRequest{
+		Executable:    exe,
+		Args:          []string{"-test.run=TestSubprocessHelper", "--", "printenv"},
+		EnvOverrides:  map[string]string{"SUBPROCESS_PARENT_VALUE": "override-value"},
+		StdoutLogPath: stdoutPath,
+	}
+
+	if _, err := Run(context.Background(), req); err != nil {
+		t.Fatalf("Run() error = %v", err)
+	}
+	data, err := os.ReadFile(stdoutPath)
+	if err != nil {
+		t.Fatalf("read stdout log: %v", err)
+	}
+	if strings.TrimSpace(string(data)) != "override-value" {
+		t.Fatalf("stdout = %q, want override-value", strings.TrimSpace(string(data)))
+	}
+}
+
 func TestWriteYAMLAtomic(t *testing.T) {
 	dir := t.TempDir()
 	path := filepath.Join(dir, "config.generated.yml")
@@ -190,6 +251,10 @@ func TestSubprocessHelper(t *testing.T) {
 	case "sleep":
 		time.Sleep(500 * time.Millisecond)
 		os.Exit(0)
+	case "printenv":
+		key := os.Getenv("SUBPROCESS_HELPER_ENV_KEY")
+		_, _ = os.Stdout.WriteString(os.Getenv(key) + "\n")
+		os.Exit(0)
 	default:
 		os.Exit(2)
 	}