test: add more sorting tests

tagcmp_test.go

@@ -617,7 +617,7 @@ func TestIsCompatible(t *testing.T) {
 	}
 }
 
-func TestSort(t *testing.T) {
+func TestSort1(t *testing.T) {
 	rawTags := []string{
 		"v1.4.8",
 		"v1.3.9",
@@ -656,6 +656,43 @@ func TestSort(t *testing.T) {
 	}
 }
 
+func TestSort2(t *testing.T) {
+	rawTags := []string{
+		"10.0",
+		"10.6",
+		"10.2",
+		"10.1",
+		"10.5",
+		"5.5",
+	}
+
+	var tags []tagcmp.Tag
+	for _, rawTag := range rawTags {
+		tag, err := tagcmp.Parse(rawTag)
+		if err != nil {
+			t.Errorf("'%s' should have parsed but didn't: %s", tag, err)
+		}
+		tags = append(tags, tag)
+	}
+
+	sort.Sort(tagcmp.ByTag(tags))
+
+	expected := []string{
+		"5.5",
+		"10.0",
+		"10.1",
+		"10.2",
+		"10.5",
+		"10.6",
+	}
+
+	for idx, tag := range tags {
+		if tag.String() != expected[idx] {
+			t.Errorf("'%s' sorted out of order, saw '%s', expected '%s'", tag, tags, expected)
+		}
+	}
+}
+
 func TestString(t *testing.T) {
 	for _, tag := range supported {
 		p, err := tagcmp.Parse(tag)