add tests

Signed-off-by: Jameel Al-Aziz <jameel@bastion.io>

src/cmd/linuxkit/util/reference_test.go

@@ -0,0 +1,59 @@
+package util
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestReferenceExpand(t *testing.T) {
+	tests := []struct {
+		name    string
+		ref     string
+		options []ReferenceOption
+		want    string
+	}{
+		{
+			"basic image name should expand to docker.io/library image",
+			"redis",
+			nil,
+			"docker.io/library/redis",
+		},
+		{
+			"image name with user/org should expand to docker.io image",
+			"foo/bar",
+			nil,
+			"docker.io/foo/bar",
+		},
+		{
+			"custom registry image name should not expand",
+			"myregistry.io/foo",
+			nil,
+			"myregistry.io/foo",
+		},
+		{
+			"image name with more than three parts should not expand",
+			"foo/bar/baz",
+			nil,
+			"foo/bar/baz",
+		},
+		{
+			"with tag should add latest if image does not have tag",
+			"redis",
+			[]ReferenceOption{ReferenceWithTag()},
+			"docker.io/library/redis:latest",
+		},
+		{
+			"with tag should not add latest if image already has tag",
+			"redis:alpine",
+			[]ReferenceOption{ReferenceWithTag()},
+			"docker.io/library/redis:alpine",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := ReferenceExpand(tt.ref, tt.options...)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}