feat(commands): add insertFinalNewLine (#241126)

* feat(commands): add `insertFinalNewLine`

* refactor: move `insertFinalNewLine` command from `common` folder

* refactor: remove redunant code

* very minor change

src/vs/editor/contrib/insertFinalNewLine/browser/insertFinalNewLine.ts

@@ -0,0 +1,38 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { ICodeEditor } from '../../../browser/editorBrowser.js';
+import { EditorAction, registerEditorAction, ServicesAccessor } from '../../../browser/editorExtensions.js';
+import { InsertFinalNewLineCommand } from './insertFinalNewLineCommand.js';
+import { EditorContextKeys } from '../../../common/editorContextKeys.js';
+import * as nls from '../../../../nls.js';
+
+export class InsertFinalNewLineAction extends EditorAction {
+
+	public static readonly ID = 'editor.action.insertFinalNewLine';
+
+	constructor() {
+		super({
+			id: InsertFinalNewLineAction.ID,
+			label: nls.localize2('insertFinalNewLine', "Insert Final New Line"),
+			precondition: EditorContextKeys.writable
+		});
+	}
+
+	public run(_accessor: ServicesAccessor, editor: ICodeEditor, args: any): void {
+		const selection = editor.getSelection();
+		if (selection === null) {
+			return;
+		}
+
+		const command = new InsertFinalNewLineCommand(selection);
+
+		editor.pushUndoStop();
+		editor.executeCommands(this.id, [command]);
+		editor.pushUndoStop();
+	}
+}
+
+registerEditorAction(InsertFinalNewLineAction);

src/vs/editor/contrib/insertFinalNewLine/browser/insertFinalNewLineCommand.ts

@@ -0,0 +1,54 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as strings from '../../../../base/common/strings.js';
+import { EditOperation, ISingleEditOperation } from '../../../common/core/editOperation.js';
+import { Position } from '../../../common/core/position.js';
+import { Selection } from '../../../common/core/selection.js';
+import { ICommand, ICursorStateComputerData, IEditOperationBuilder } from '../../../common/editorCommon.js';
+import { ITextModel } from '../../../common/model.js';
+
+export class InsertFinalNewLineCommand implements ICommand {
+
+	private readonly _selection: Selection;
+	private _selectionId: string | null;
+
+
+	constructor(selection: Selection) {
+		this._selection = selection;
+		this._selectionId = null;
+	}
+
+	public getEditOperations(model: ITextModel, builder: IEditOperationBuilder): void {
+		const op = insertFinalNewLine(model);
+		if (op) {
+			builder.addEditOperation(op.range, op.text);
+		}
+		this._selectionId = builder.trackSelection(this._selection);
+	}
+
+	public computeCursorState(model: ITextModel, helper: ICursorStateComputerData): Selection {
+		return helper.getTrackedSelection(this._selectionId!);
+	}
+}
+
+/**
+ * Generate edit operations for inserting a final new line if needed.
+ * Returns undefined if no edit is needed.
+ */
+export function insertFinalNewLine(model: ITextModel): ISingleEditOperation | undefined {
+	const lineCount = model.getLineCount();
+	const lastLine = model.getLineContent(lineCount);
+	const lastLineIsEmptyOrWhitespace = strings.lastNonWhitespaceIndex(lastLine) === -1;
+
+	if (!lineCount || lastLineIsEmptyOrWhitespace) {
+		return;
+	}
+
+	return EditOperation.insert(
+		new Position(lineCount, model.getLineMaxColumn(lineCount)),
+		model.getEOL()
+	);
+}

src/vs/editor/editor.all.ts

@@ -35,6 +35,7 @@ import './contrib/hover/browser/hoverContribution.js';
 import './contrib/indentation/browser/indentation.js';
 import './contrib/inlayHints/browser/inlayHintsContribution.js';
 import './contrib/inPlaceReplace/browser/inPlaceReplace.js';
+import './contrib/insertFinalNewLine/browser/insertFinalNewLine.js';
 import './contrib/lineSelection/browser/lineSelection.js';
 import './contrib/linesOperations/browser/linesOperations.js';
 import './contrib/linkedEditing/browser/linkedEditing.js';