Accept array or single item for output items methods

#119601

src/vs/vscode.proposed.d.ts

@@ -1575,8 +1575,8 @@ declare module 'vscode' {
 		clearOutput(cellIndex?: number): Thenable<void>;
 		appendOutput(out: NotebookCellOutput | NotebookCellOutput[], cellIndex?: number): Thenable<void>;
 		replaceOutput(out: NotebookCellOutput | NotebookCellOutput[], cellIndex?: number): Thenable<void>;
-		appendOutputItems(items: NotebookCellOutputItem[], outputId: string): Thenable<void>;
-		replaceOutputItems(items: NotebookCellOutputItem[], outputId: string): Thenable<void>;
+		appendOutputItems(items: NotebookCellOutputItem | NotebookCellOutputItem[], outputId: string): Thenable<void>;
+		replaceOutputItems(items: NotebookCellOutputItem | NotebookCellOutputItem[], outputId: string): Thenable<void>;
 	}
 
 	export enum NotebookCellExecutionState {

src/vs/workbench/api/common/extHostNotebook.ts

@@ -1186,13 +1186,15 @@ class NotebookCellExecutionTask extends Disposable {
 				return that.applyEdits([{ editType: CellEditType.Output, handle, outputs: outputs.map(typeConverters.NotebookCellOutput.from) }]);
 			},
 
-			async appendOutputItems(items: vscode.NotebookCellOutputItem[], outputId: string): Promise<void> {
+			async appendOutputItems(items: vscode.NotebookCellOutputItem | vscode.NotebookCellOutputItem[], outputId: string): Promise<void> {
 				that.verifyStateForOutput();
+				items = Array.isArray(items) ? items : [items];
 				return that.applyEdits([{ editType: CellEditType.OutputItems, append: true, items: items.map(typeConverters.NotebookCellOutputItem.from), outputId }]);
 			},
 
-			async replaceOutputItems(items: vscode.NotebookCellOutputItem[], outputId: string): Promise<void> {
+			async replaceOutputItems(items: vscode.NotebookCellOutputItem | vscode.NotebookCellOutputItem[], outputId: string): Promise<void> {
 				that.verifyStateForOutput();
+				items = Array.isArray(items) ? items : [items];
 				return that.applyEdits([{ editType: CellEditType.OutputItems, items: items.map(typeConverters.NotebookCellOutputItem.from), outputId }]);
 			},