fix(common/load/streamToUnstructured): skip empty documents

cmd/crossplane/common/load/loader.go

@@ -208,6 +208,12 @@ func streamToUnstructured(stream [][]byte) ([]*unstructured.Unstructured, error)
 		if err := yaml.Unmarshal(y, u); err != nil {
 			return nil, errors.Wrap(err, "cannot parse YAML manifest")
 		}
+
+		// skip empty documents (empty files, or documents containing only comment)
+		if len(u.Object) == 0 {
+			continue
+		}
+
 		// extract pipeline input resources
 		if u.GetObjectKind().GroupVersionKind() == v1.CompositionGroupVersionKind {
 			// Convert the unstructured resource to a Composition

cmd/crossplane/common/load/loader_test.go

@@ -486,6 +486,24 @@ spec:
 				err: nil,
 			},
 		},
+		"SkipEmptyDocuments": {
+			reason: "Return empty unstructured array for empty documents",
+			args: args{
+				stream: [][]byte{{}},
+			},
+			want: want{
+				resources: []*unstructured.Unstructured{},
+			},
+		},
+		"SkipDocumentsWithCommentOnly": {
+			reason: "Skip documents with only comments",
+			args: args{
+				stream: [][]byte{[]byte("# comment only\n")},
+			},
+			want: want{
+				resources: []*unstructured.Unstructured{},
+			},
+		},
 	}
 
 	for name, tc := range cases {