chore: add gitutils package to inspect local git repo

internal/gitutil/state_test.go

@@ -0,0 +1,152 @@
+package gitutil
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestInspectGitState_NotARepo(t *testing.T) {
+	// Create a temporary directory that's not a git repo.
+	tmpDir := t.TempDir()
+
+	state, err := InspectGitState(tmpDir)
+	require.NoError(t, err)
+
+	// If tmpDir happens to be in a git repo (e.g., parent directory), skip this test.
+	// This is common when running tests from within the project itself.
+	if state.IsRepo {
+		t.Skip("tmpDir is within a git repository, skipping test")
+	}
+
+	assert.False(t, state.IsRepo)
+	assert.Empty(t, state.SHA)
+	assert.Empty(t, state.ShortSHA(7))
+	assert.True(t, state.Time.IsZero()) // Should have zero time if not a repo.
+	assert.False(t, state.IsDirty)
+}
+
+func TestInspectGitState_CleanRepo(t *testing.T) {
+	// Create a temporary git repo.
+	tmpDir := t.TempDir()
+	initGitRepo(t, tmpDir)
+
+	createAndCommitFile(t, tmpDir, "test.txt", "test content")
+
+	state, err := InspectGitState(tmpDir)
+	require.NoError(t, err)
+
+	assert.True(t, state.IsRepo)
+	assert.Len(t, state.SHA, 40)
+	assert.Equal(t, state.ShortSHA(7), state.SHA[:7])
+	assert.False(t, state.Time.IsZero())
+	assert.False(t, state.IsDirty)
+}
+
+func TestInspectGitState_DirtyRepo(t *testing.T) {
+	// Create a temporary git repo.
+	tmpDir := t.TempDir()
+	initGitRepo(t, tmpDir)
+
+	createAndCommitFile(t, tmpDir, "test.txt", "test content")
+
+	// Modify the file to make the repo dirty.
+	err := os.WriteFile(filepath.Join(tmpDir, "test.txt"), []byte("modified content"), 0o644)
+	require.NoError(t, err)
+
+	state, err := InspectGitState(tmpDir)
+	require.NoError(t, err)
+
+	assert.True(t, state.IsRepo)
+	assert.True(t, state.IsDirty)
+}
+
+func TestInspectGitState_UntrackedFiles(t *testing.T) {
+	// Create a temporary git repo.
+	tmpDir := t.TempDir()
+	initGitRepo(t, tmpDir)
+
+	createAndCommitFile(t, tmpDir, "test.txt", "test content")
+
+	// Add an untracked file.
+	err := os.WriteFile(filepath.Join(tmpDir, "untracked.txt"), []byte("untracked"), 0o644)
+	require.NoError(t, err)
+
+	state, err := InspectGitState(tmpDir)
+	require.NoError(t, err)
+
+	assert.True(t, state.IsRepo)
+	assert.True(t, state.IsDirty) // Untracked files make the repo dirty.
+}
+
+func TestGitState_ShortSHA(t *testing.T) {
+	state := &GitState{
+		SHA: "1234567890abcdef1234567890abcdef12345678",
+	}
+
+	tests := []struct {
+		name     string
+		length   int
+		expected string
+	}{
+		{"short 7", 7, "1234567"},
+		{"short 10", 10, "1234567890"},
+		{"full SHA", 40, "1234567890abcdef1234567890abcdef12345678"},
+		{"longer than SHA", 50, "1234567890abcdef1234567890abcdef12345678"},
+		{"negative", -42, "1234567890abcdef1234567890abcdef12345678"},
+		{"zero", 0, "1234567890abcdef1234567890abcdef12345678"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := state.ShortSHA(tt.length)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestGitState_ShortSHA_Empty(t *testing.T) {
+	state := &GitState{
+		SHA: "",
+	}
+
+	result := state.ShortSHA(7)
+	assert.Empty(t, result)
+}
+
+// Helper functions.
+
+func initGitRepo(t *testing.T, dir string) {
+	t.Helper()
+
+	// Initialize git repo.
+	runGitCommand(t, dir, "init")
+	runGitCommand(t, dir, "config", "user.email", "test@example.com")
+	runGitCommand(t, dir, "config", "user.name", "Test User")
+}
+
+func createAndCommitFile(t *testing.T, dir, filename, content string) {
+	t.Helper()
+
+	// Create file.
+	path := filepath.Join(dir, filename)
+	err := os.WriteFile(path, []byte(content), 0o644)
+	require.NoError(t, err)
+
+	// Commit file.
+	runGitCommand(t, dir, "add", filename)
+	runGitCommand(t, dir, "commit", "-m", "Add "+filename)
+}
+
+func runGitCommand(t *testing.T, dir string, args ...string) {
+	t.Helper()
+
+	cmd := exec.Command("git", args...)
+	cmd.Dir = dir
+	output, err := cmd.CombinedOutput()
+	require.NoError(t, err, "git command failed: %s", output)
+}