add test suite

internal/git/git_test.go

@@ -0,0 +1,48 @@
+package git
+
+import (
+	"os/exec"
+	"strings"
+	"testing"
+)
+
+func TestFormatCommitLine_nil(t *testing.T) {
+	if got := FormatCommitLine(nil); got != "" {
+		t.Errorf("FormatCommitLine(nil) = %q; want empty", got)
+	}
+}
+
+func TestFormatCommitLine_valid(t *testing.T) {
+	commit := &CommitInfo{
+		ShortSHA: "abc1234",
+		Message:  "Initial commit",
+	}
+	expected := "> Commit: abc1234 (Initial commit)\n"
+	if got := FormatCommitLine(commit); got != expected {
+		t.Errorf("FormatCommitLine() = %q; want %q", got, expected)
+	}
+}
+
+func TestGetCommitInfo_no_git(t *testing.T) {
+	cmd := exec.Command("git", "-C", "/nonexistent", "log", "-1", "--format=%h %s")
+	output, err := cmd.Output()
+	if err == nil {
+		t.Fatalf("expected error from nonexistent path, got %s", string(output))
+	}
+
+	result := GetCommitInfo("/nonexistent")
+	if result != nil {
+		t.Errorf("GetCommitInfo(/nonexistent) = %v; want nil", result)
+	}
+}
+
+func TestGetCommitInfo_no_commits(t *testing.T) {
+	out, err := exec.Command("sh", "-c", "echo 'abc123'").Output()
+	if err != nil {
+		t.Skip("shell command failed")
+	}
+	parts := strings.SplitN(strings.TrimSpace(string(out)), " ", 2)
+	if len(parts) < 2 {
+		t.Skip("cannot verify single-part output")
+	}
+}