tests: add test for latest tag selection

Signed-off-by: Richard Gee <richard@technologee.co.uk>

cmd/chart/upgrade.go

@@ -162,22 +162,12 @@ func updateImages(iName string, v bool) (bool, string, error) {
 		return false, iName, errors.New("unable to list tags for " + imageName)
 	}
 
-	var vs []*semver.Version
-	for _, r := range ref {
-		v, err := semver.NewVersion(r)
-		if err == nil {
-			vs = append(vs, v)
-		}
-	}
+	latestTag, hasLaterTag := getLatestTag(ref)
 
-	if len(vs) == 0 {
+	if !hasLaterTag {
 		return false, iName, fmt.Errorf("no valid semver tags found for %s", imageName)
 	}
 
-	sort.Sort(sort.Reverse(semver.Collection(vs)))
-
-	latestTag := vs[0].Original()
-
 	laterVersionB := false
 
 	// AE: Don't upgrade to an RC tag, even if it's newer.
@@ -206,3 +196,22 @@ func tagIsUpgradeable(currentTag, latestTag string) bool {
 	return latestSemVer.Compare(currentSemVer) == 1 && latestSemVer.Prerelease() == currentSemVer.Prerelease()
 
 }
+
+func getLatestTag(discoveredTags []string) (string, bool) {
+
+	var vs []*semver.Version
+	for _, tag := range discoveredTags {
+		v, err := semver.NewVersion(tag)
+		if err == nil {
+			vs = append(vs, v)
+		}
+	}
+
+	if len(vs) > 0 {
+		sort.Sort(sort.Reverse(semver.Collection(vs)))
+		return vs[0].Original(), true
+	}
+
+	return "", false
+
+}

cmd/chart/upgrade_test.go

@@ -103,3 +103,58 @@ func Test_tagIsUpgradable(t *testing.T) {
 		})
 	}
 }
+
+func TestGetLatestTag(t *testing.T) {
+	tests := []struct {
+		name           string
+		discoveredTags []string
+		expectedTag    string
+		expectedFound  bool
+	}{
+		{
+			name:           "Valid semantic tags",
+			discoveredTags: []string{"v1.0.0", "v2.1.0", "v2.3.4", "v2.3.3"},
+			expectedTag:    "v2.3.4",
+			expectedFound:  true,
+		},
+		{
+			name:           "No valid semantic tags",
+			discoveredTags: []string{"invalid", "v.a.b", "xyz"},
+			expectedTag:    "",
+			expectedFound:  false,
+		},
+		{
+			name:           "Empty list",
+			discoveredTags: []string{},
+			expectedTag:    "",
+			expectedFound:  false,
+		},
+		{
+			name:           "Mixed valid and invalid tags",
+			discoveredTags: []string{"v1.0.0", "invalid", "v2.1.0-beta", "v1.2.3"},
+			expectedTag:    "v2.1.0-beta",
+			expectedFound:  true,
+		},
+		{
+			name:           "similar tag values",
+			discoveredTags: []string{"17", "17.0", "17.0.0"},
+			expectedTag:    "17",
+			expectedFound:  true,
+		},
+		{
+			name:           "similar tag values different arrival order",
+			discoveredTags: []string{"17.0", "17", "17.0.0"},
+			expectedTag:    "17.0",
+			expectedFound:  true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			tag, found := getLatestTag(tc.discoveredTags)
+			if tag != tc.expectedTag || found != tc.expectedFound {
+				t.Errorf("getLatestTag(%v) = (%v, %v), want (%v, %v)", tc.discoveredTags, tag, found, tc.expectedTag, tc.expectedFound)
+			}
+		})
+	}
+}