Extract chart repo url normalization logic

Move the logic to helm/utils exported as func
NormalizeChartRepositoryURL

Signed-off-by: Aurel Canciu <aurelcanciu@gmail.com>

controllers/helmchart_controller.go

@@ -591,10 +591,8 @@ func (r *HelmChartReconciler) indexHelmRepositoryByURL(o runtime.Object) []strin
 	if !ok {
 		panic(fmt.Sprintf("Expected a HelmRepository, got %T", o))
 	}
-	if repo.Spec.URL != "" {
-		// TODO(hidde): move this to a dedicated function in the internal Helm package
-		//   so it can be re-used for e.g. lookups.
-		u := strings.TrimRight(repo.Spec.URL, "/") + "/"
+	u := helm.NormalizeChartRepositoryURL(repo.Spec.URL)
+	if u != "" {
 		return []string{u}
 	}
 	return nil

internal/helm/utils.go

@@ -0,0 +1,27 @@
+/*
+Copyright 2020 The Flux CD contributors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package helm
+
+import "strings"
+
+// NormalizeChartRepositoryURL ensures repository urls are normalized
+func NormalizeChartRepositoryURL(url string) string {
+	if url != "" {
+		return strings.TrimRight(url, "/") + "/"
+	}
+	return url
+}