add keyset length check (#277)

* add keyset length check

Signed-off-by: Stephanie <[email protected]>

* check conflict between plugins and parent

Signed-off-by: Stephanie <[email protected]>

Author: yangcao77

pkg/utils/overriding/merging.go

@@ -36,6 +36,10 @@ func MergeDevWorkspaceTemplateSpec(
 	if err := ensureNoConflictsWithPlugins(mainContent, pluginFlattenedContents...); err != nil {
 		return nil, err
 	}
+	// also need to ensure no conflict between parent and plugins
+	if err := ensureNoConflictsWithPlugins(parentFlattenedContent, pluginFlattenedContents...); err != nil {
+		return nil, err
+	}
 
 	result := workspaces.DevWorkspaceTemplateSpecContent{}
 

pkg/utils/overriding/overriding.go

@@ -116,6 +116,9 @@ func OverrideDevWorkspaceTemplateSpec(original *workspaces.DevWorkspaceTemplateS
 
 func ensureOnlyExistingElementsAreOverridden(spec *workspaces.DevWorkspaceTemplateSpecContent, overrides workspaces.Overrides) error {
 	return checkKeys(func(elementType string, keysSets []sets.String) []error {
+		if len(keysSets) <= 1 {
+			return []error{}
+		}
 		specKeys := keysSets[0]
 		overlayKeys := keysSets[1]
 		newElementsInOverlay := overlayKeys.Difference(specKeys)