Skip tests that use git when git is not available

pkg/image/build_test.go

@@ -7,7 +7,17 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+var hasGit = (func() bool {
+	_, err := exec.LookPath("git")
+	return err == nil
+})()
+
 func setupGitWorkTree(t *testing.T) string {
+	if !hasGit {
+		t.Skip("no git executable available")
+		return ""
+	}
+
 	r := require.New(t)
 
 	tmp := t.TempDir()
@@ -27,39 +37,56 @@ func TestIsGitWorkTree(t *testing.T) {
 }
 
 func TestGitHead(t *testing.T) {
-	r := require.New(t)
-	tmp := setupGitWorkTree(t)
-
-	head, err := gitHead(tmp)
-	r.NoError(err)
-	r.NotEqual("", head)
-
-	head, err = gitHead("/dev/null")
-	r.Error(err)
-	r.Equal("", head)
-
-	t.Setenv("GITHUB_SHA", "fafafaf")
-
-	head, err = gitHead("/dev/null")
-	r.NoError(err)
-	r.Equal("fafafaf", head)
+	t.Run("via github env", func(t *testing.T) {
+		t.Setenv("GITHUB_SHA", "fafafaf")
+
+		head, err := gitHead("/dev/null")
+
+		require.NoError(t, err)
+		require.Equal(t, "fafafaf", head)
+	})
+
+	t.Run("via git", func(t *testing.T) {
+		tmp := setupGitWorkTree(t)
+		if tmp == "" {
+			return
+		}
+
+		head, err := gitHead(tmp)
+		require.NoError(t, err)
+		require.NotEqual(t, "", head)
+	})
+
+	t.Run("unavailable", func(t *testing.T) {
+		head, err := gitHead("/dev/null")
+		require.Error(t, err)
+		require.Equal(t, "", head)
+	})
 }
 
 func TestGitTag(t *testing.T) {
-	r := require.New(t)
-	tmp := setupGitWorkTree(t)
-
-	tag, err := gitTag(tmp)
-	r.NoError(err)
-	r.Equal("v0.0.1+walrus", tag)
-
-	tag, err = gitTag("/dev/null")
-	r.Error(err)
-	r.Equal("", tag)
-
-	t.Setenv("GITHUB_REF_NAME", "v0.0.1+manatee")
-
-	tag, err = gitTag("/dev/null")
-	r.NoError(err)
-	r.Equal("v0.0.1+manatee", tag)
+	t.Run("via github env", func(t *testing.T) {
+		t.Setenv("GITHUB_REF_NAME", "v0.0.1+manatee")
+
+		tag, err := gitTag("/dev/null")
+		require.NoError(t, err)
+		require.Equal(t, "v0.0.1+manatee", tag)
+	})
+
+	t.Run("via git", func(t *testing.T) {
+		tmp := setupGitWorkTree(t)
+		if tmp == "" {
+			return
+		}
+
+		tag, err := gitTag(tmp)
+		require.NoError(t, err)
+		require.Equal(t, "v0.0.1+walrus", tag)
+	})
+
+	t.Run("unavailable", func(t *testing.T) {
+		tag, err := gitTag("/dev/null")
+		require.Error(t, err)
+		require.Equal(t, "", tag)
+	})
 }