test: expand routing and compact coverage

internal/compact/git.go

@@ -1,21 +1,20 @@
 package compact
 
 import (
-	"bytes"
 	"os/exec"
 	"strings"
 )
 
+var gitExec = func(name string, args ...string) ([]byte, error) {
+	return exec.Command(name, args...).Output()
+}
+
 // GetCurrentCommitHash returns the current git HEAD commit hash.
 // Returns empty string if not in a git repository or if git command fails.
 func GetCurrentCommitHash() string {
-	cmd := exec.Command("git", "rev-parse", "HEAD")
-	var out bytes.Buffer
-	cmd.Stdout = &out
-	
-	if err := cmd.Run(); err != nil {
+	output, err := gitExec("git", "rev-parse", "HEAD")
+	if err != nil {
 		return ""
 	}
-	
-	return strings.TrimSpace(out.String())
+	return strings.TrimSpace(string(output))
 }

internal/compact/git_test.go

@@ -0,0 +1,30 @@
+package compact
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestGetCurrentCommitHashSuccess(t *testing.T) {
+	orig := gitExec
+	gitExec = func(string, ...string) ([]byte, error) {
+		return []byte("abc123\n"), nil
+	}
+	t.Cleanup(func() { gitExec = orig })
+
+	if got := GetCurrentCommitHash(); got != "abc123" {
+		t.Fatalf("expected trimmed hash, got %q", got)
+	}
+}
+
+func TestGetCurrentCommitHashError(t *testing.T) {
+	orig := gitExec
+	gitExec = func(string, ...string) ([]byte, error) {
+		return nil, errors.New("boom")
+	}
+	t.Cleanup(func() { gitExec = orig })
+
+	if got := GetCurrentCommitHash(); got != "" {
+		t.Fatalf("expected empty string on error, got %q", got)
+	}
+}