Avoid computing undo edits if not necessary

src/vs/editor/common/model.ts

@@ -1092,9 +1092,11 @@ export interface ITextModel {
 	 * Edit the model without adding the edits to the undo stack.
 	 * This can have dire consequences on the undo stack! See @pushEditOperations for the preferred way.
 	 * @param operations The edit operations.
-	 * @return The inverse edit operations, that, when applied, will bring the model back to the previous state.
+	 * @return If desired, the inverse edit operations, that, when applied, will bring the model back to the previous state.
 	 */
-	applyEdits(operations: IIdentifiedSingleEditOperation[]): IValidEditOperation[];
+	applyEdits(operations: IIdentifiedSingleEditOperation[]): void;
+	applyEdits(operations: IIdentifiedSingleEditOperation[], computeUndoEdits: false): void;
+	applyEdits(operations: IIdentifiedSingleEditOperation[], computeUndoEdits: true): IValidEditOperation[];
 
 	/**
 	 * Change the end of line sequence without recording in the undo stack.
@@ -1299,7 +1301,7 @@ export interface ITextBuffer {
 export class ApplyEditsResult {
 
 	constructor(
-		public readonly reverseEdits: IValidEditOperation[],
+		public readonly reverseEdits: IValidEditOperation[] | null,
 		public readonly changes: IInternalModelContentChange[],
 		public readonly trimAutoWhitespaceLineNumbers: number[] | null
 	) { }

src/vs/editor/common/model/editStack.ts

@@ -326,7 +326,7 @@ export class EditStack {
 
 	public pushEditOperation(beforeCursorState: Selection[] | null, editOperations: IIdentifiedSingleEditOperation[], cursorStateComputer: ICursorStateComputer | null): Selection[] | null {
 		const editStackElement = this._getOrCreateEditStackElement(beforeCursorState);
-		const inverseEditOperations = this._model.applyEdits(editOperations);
+		const inverseEditOperations = this._model.applyEdits(editOperations, true);
 		const afterCursorState = EditStack._computeCursorState(cursorStateComputer, inverseEditOperations);
 		editStackElement.append(this._model, inverseEditOperations, getModelEOL(this._model), this._model.getAlternativeVersionId(), afterCursorState);
 		return afterCursorState;

src/vs/editor/common/model/pieceTreeTextBuffer/pieceTreeTextBuffer.ts

@@ -261,6 +261,20 @@ export class PieceTreeTextBuffer implements ITextBuffer {
 		// Sort operations ascending
 		operations.sort(PieceTreeTextBuffer._sortOpsAscending);
 
+		let hasTouchingRanges = false;
+		for (let i = 0, count = operations.length - 1; i < count; i++) {
+			let rangeEnd = operations[i].range.getEndPosition();
+			let nextRangeStart = operations[i + 1].range.getStartPosition();
+
+			if (nextRangeStart.isBeforeOrEqual(rangeEnd)) {
+				if (nextRangeStart.isBefore(rangeEnd)) {
+					// overlapping ranges
+					throw new Error('Overlapping ranges are not allowed!');
+				}
+				hasTouchingRanges = true;
+			}
+		}
+
 		if (canReduceOperations) {
 			operations = this._reduceOperations(operations);
 		}
@@ -289,24 +303,11 @@ export class PieceTreeTextBuffer implements ITextBuffer {
 			}
 		}
 
-		let reverseOperations: IReverseSingleEditOperation[] = [];
+		let reverseOperations: IReverseSingleEditOperation[] | null = null;
 		if (computeUndoEdits) {
 
-			let hasTouchingRanges = false;
-			for (let i = 0, count = operations.length - 1; i < count; i++) {
-				let rangeEnd = operations[i].range.getEndPosition();
-				let nextRangeStart = operations[i + 1].range.getStartPosition();
-
-				if (nextRangeStart.isBeforeOrEqual(rangeEnd)) {
-					if (nextRangeStart.isBefore(rangeEnd)) {
-						// overlapping ranges
-						throw new Error('Overlapping ranges are not allowed!');
-					}
-					hasTouchingRanges = true;
-				}
-			}
-
 			let reverseRangeDeltaOffset = 0;
+			reverseOperations = [];
 			for (let i = 0; i < operations.length; i++) {
 				const op = operations[i];
 				const reverseRange = reverseRanges[i];

src/vs/editor/common/model/textModel.ts

@@ -1330,18 +1330,22 @@ export class TextModel extends Disposable implements model.ITextModel {
 		}
 	}
 
-	public applyEdits(rawOperations: model.IIdentifiedSingleEditOperation[], computeUndoEdits: boolean = true): model.IValidEditOperation[] {
+	public applyEdits(operations: model.IIdentifiedSingleEditOperation[]): void;
+	public applyEdits(operations: model.IIdentifiedSingleEditOperation[], computeUndoEdits: false): void;
+	public applyEdits(operations: model.IIdentifiedSingleEditOperation[], computeUndoEdits: true): model.IValidEditOperation[];
+	public applyEdits(rawOperations: model.IIdentifiedSingleEditOperation[], computeUndoEdits: boolean = false): void | model.IValidEditOperation[] {
 		try {
 			this._onDidChangeDecorations.beginDeferredEmit();
 			this._eventEmitter.beginDeferredEmit();
-			return this._doApplyEdits(this._validateEditOperations(rawOperations), computeUndoEdits);
+			const operations = this._validateEditOperations(rawOperations);
+			return this._doApplyEdits(operations, computeUndoEdits);
 		} finally {
 			this._eventEmitter.endDeferredEmit();
 			this._onDidChangeDecorations.endDeferredEmit();
 		}
 	}
 
-	private _doApplyEdits(rawOperations: model.ValidAnnotatedEditOperation[], computeUndoEdits: boolean): model.IValidEditOperation[] {
+	private _doApplyEdits(rawOperations: model.ValidAnnotatedEditOperation[], computeUndoEdits: boolean): void | model.IValidEditOperation[] {
 
 		const oldLineCount = this._buffer.getLineCount();
 		const result = this._buffer.applyEdits(rawOperations, this._options.trimAutoWhitespace, computeUndoEdits);
@@ -1419,7 +1423,7 @@ export class TextModel extends Disposable implements model.ITextModel {
 			);
 		}
 
-		return result.reverseEdits;
+		return (result.reverseEdits === null ? undefined : result.reverseEdits);
 	}
 
 	public undo(): void {

src/vs/editor/test/common/model/editableTextModel.test.ts

@@ -1104,7 +1104,7 @@ suite('EditorModel - EditableTextModel.applyEdits', () => {
 			{ range: new Range(3, 1, 3, 6), text: null, },
 			{ range: new Range(2, 1, 3, 1), text: null, },
 			{ range: new Range(3, 6, 3, 6), text: '\nline2' }
-		]);
+		], true);
 
 		model.applyEdits(undoEdits);
 

src/vs/editor/test/common/model/editableTextModelTestUtils.ts

@@ -17,7 +17,7 @@ export function testApplyEditsWithSyncedModels(original: string[], edits: IIdent
 
 	assertSyncedModels(originalStr, (model, assertMirrorModels) => {
 		// Apply edits & collect inverse edits
-		let inverseEdits = model.applyEdits(edits);
+		let inverseEdits = model.applyEdits(edits, true);
 
 		// Assert edits produced expected result
 		assert.deepEqual(model.getValue(EndOfLinePreference.LF), expectedStr);
@@ -25,7 +25,7 @@ export function testApplyEditsWithSyncedModels(original: string[], edits: IIdent
 		assertMirrorModels();
 
 		// Apply the inverse edits
-		let inverseInverseEdits = model.applyEdits(inverseEdits);
+		let inverseInverseEdits = model.applyEdits(inverseEdits, true);
 
 		// Assert the inverse edits brought back model to original state
 		assert.deepEqual(model.getValue(EndOfLinePreference.LF), originalStr);

src/vs/editor/test/common/model/model.test.ts

@@ -330,7 +330,7 @@ suite('Editor Model - Model', () => {
 		let res = thisModel.applyEdits([
 			{ range: new Range(2, 1, 2, 1), text: 'a' },
 			{ range: new Range(1, 1, 1, 1), text: 'b' },
-		]);
+		], true);
 
 		assert.deepEqual(res[0].range, new Range(2, 1, 2, 2));
 		assert.deepEqual(res[1].range, new Range(1, 1, 1, 2));

src/vs/editor/test/common/model/modelEditOperation.test.ts

@@ -50,14 +50,14 @@ suite('Editor Model - Model Edit Operation', () => {
 	function assertSingleEditOp(singleEditOp: IIdentifiedSingleEditOperation, editedLines: string[]) {
 		let editOp = [singleEditOp];
 
-		let inverseEditOp = model.applyEdits(editOp);
+		let inverseEditOp = model.applyEdits(editOp, true);
 
 		assert.equal(model.getLineCount(), editedLines.length);
 		for (let i = 0; i < editedLines.length; i++) {
 			assert.equal(model.getLineContent(i + 1), editedLines[i]);
 		}
 
-		let originalOp = model.applyEdits(inverseEditOp);
+		let originalOp = model.applyEdits(inverseEditOp, true);
 
 		assert.equal(model.getLineCount(), 5);
 		assert.equal(model.getLineContent(1), LINE1);

src/vs/monaco.d.ts

@@ -1902,9 +1902,11 @@ declare namespace monaco.editor {
 		 * Edit the model without adding the edits to the undo stack.
 		 * This can have dire consequences on the undo stack! See @pushEditOperations for the preferred way.
 		 * @param operations The edit operations.
-		 * @return The inverse edit operations, that, when applied, will bring the model back to the previous state.
+		 * @return If desired, the inverse edit operations, that, when applied, will bring the model back to the previous state.
 		 */
-		applyEdits(operations: IIdentifiedSingleEditOperation[]): IValidEditOperation[];
+		applyEdits(operations: IIdentifiedSingleEditOperation[]): void;
+		applyEdits(operations: IIdentifiedSingleEditOperation[], computeUndoEdits: false): void;
+		applyEdits(operations: IIdentifiedSingleEditOperation[], computeUndoEdits: true): IValidEditOperation[];
 		/**
 		 * Change the end of line sequence without recording in the undo stack.
 		 * This can have dire consequences on the undo stack! See @pushEOL for the preferred way.

src/vs/workbench/contrib/bulkEdit/browser/bulkEditPreview.ts

@@ -399,7 +399,7 @@ export class BulkEditPreviewProvider implements ITextModelContentProvider {
 		}
 		// apply new edits and keep (future) undo edits
 		const newEdits = this._operations.getFileEdits(uri);
-		const newUndoEdits = model.applyEdits(newEdits);
+		const newUndoEdits = model.applyEdits(newEdits, true);
 		this._modelPreviewEdits.set(model.id, newUndoEdits);
 	}