diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/workspace.event.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/workspace.event.test.ts
new file mode 100644
index 0000000000000000000000000000000000000000..070b6818d7282c857d0dfd0cc902d87030aa7e64
--- /dev/null
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/workspace.event.test.ts
@@ -0,0 +1,131 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as assert from 'assert';
+import * as vscode from 'vscode';
+import { createRandomFile } from '../utils';
+
+suite('workspace-event', () => {
+
+	const disposables: vscode.Disposable[] = [];
+
+	teardown(() => {
+		for (const dispo of disposables) {
+			dispo.dispose();
+		}
+		disposables.length = 0;
+	});
+
+	test('onWillCreate/onDidCreate', async function () {
+
+		const base = await createRandomFile();
+		const newUri = base.with({ path: base.path + '-foo' });
+
+		let onWillCreate: vscode.FileWillCreateEvent | undefined;
+		let onDidCreate: vscode.FileCreateEvent | undefined;
+
+		disposables.push(vscode.workspace.onWillCreateFiles(e => onWillCreate = e));
+		disposables.push(vscode.workspace.onDidCreateFiles(e => onDidCreate = e));
+
+		const edit = new vscode.WorkspaceEdit();
+		edit.createFile(newUri);
+
+		const success = await vscode.workspace.applyEdit(edit);
+		assert.ok(success);
+
+		assert.ok(onWillCreate);
+		assert.equal(onWillCreate?.creating.length, 1);
+		assert.equal(onWillCreate?.creating[0].toString(), newUri.toString());
+
+		assert.ok(onDidCreate);
+		assert.equal(onDidCreate?.created.length, 1);
+		assert.equal(onDidCreate?.created[0].toString(), newUri.toString());
+	});
+
+	test('onWillDelete/onDidDelete', async function () {
+
+		const base = await createRandomFile();
+
+		let onWilldelete: vscode.FileWillDeleteEvent | undefined;
+		let onDiddelete: vscode.FileDeleteEvent | undefined;
+
+		disposables.push(vscode.workspace.onWillDeleteFiles(e => onWilldelete = e));
+		disposables.push(vscode.workspace.onDidDeleteFiles(e => onDiddelete = e));
+
+		const edit = new vscode.WorkspaceEdit();
+		edit.deleteFile(base);
+
+		const success = await vscode.workspace.applyEdit(edit);
+		assert.ok(success);
+
+		assert.ok(onWilldelete);
+		assert.equal(onWilldelete?.deleting.length, 1);
+		assert.equal(onWilldelete?.deleting[0].toString(), base.toString());
+
+		assert.ok(onDiddelete);
+		assert.equal(onDiddelete?.deleted.length, 1);
+		assert.equal(onDiddelete?.deleted[0].toString(), base.toString());
+	});
+
+	test('onWillRename/onDidRename', async function () {
+
+		const oldUri = await createRandomFile();
+		const newUri = oldUri.with({ path: oldUri.path + '-NEW' });
+
+		let onWillRename: vscode.FileWillRenameEvent | undefined;
+		let onDidRename: vscode.FileRenameEvent | undefined;
+
+		disposables.push(vscode.workspace.onWillRenameFiles(e => onWillRename = e));
+		disposables.push(vscode.workspace.onDidRenameFiles(e => onDidRename = e));
+
+		const edit = new vscode.WorkspaceEdit();
+		edit.renameFile(oldUri, newUri);
+
+		const success = await vscode.workspace.applyEdit(edit);
+		assert.ok(success);
+
+		assert.ok(onWillRename);
+		assert.equal(onWillRename?.renaming.length, 1);
+		assert.equal(onWillRename?.renaming[0].oldUri.toString(), oldUri.toString());
+		assert.equal(onWillRename?.renaming[0].newUri.toString(), newUri.toString());
+
+		assert.ok(onDidRename);
+		assert.equal(onDidRename?.renamed.length, 1);
+		assert.equal(onDidRename?.renamed[0].oldUri.toString(), oldUri.toString());
+		assert.equal(onDidRename?.renamed[0].newUri.toString(), newUri.toString());
+	});
+
+	test('onWillRename - make changes', async function () {
+
+		const oldUri = await createRandomFile('BAR');
+		const newUri = oldUri.with({ path: oldUri.path + '-NEW' });
+
+		const anotherFile = await createRandomFile('BAR');
+
+		let onWillRename: vscode.FileWillRenameEvent | undefined;
+
+		disposables.push(vscode.workspace.onWillRenameFiles(e => {
+			onWillRename = e;
+			const edit = new vscode.WorkspaceEdit();
+			edit.insert(e.renaming[0].oldUri, new vscode.Position(0, 0), 'FOO');
+			edit.replace(anotherFile, new vscode.Range(0, 0, 0, 3), 'FARBOO');
+			e.waitUntil(Promise.resolve(edit));
+		}));
+
+		const edit = new vscode.WorkspaceEdit();
+		edit.renameFile(oldUri, newUri);
+
+		const success = await vscode.workspace.applyEdit(edit);
+		assert.ok(success);
+
+		assert.ok(onWillRename);
+		assert.equal(onWillRename?.renaming.length, 1);
+		assert.equal(onWillRename?.renaming[0].oldUri.toString(), oldUri.toString());
+		assert.equal(onWillRename?.renaming[0].newUri.toString(), newUri.toString());
+
+		assert.equal((await vscode.workspace.openTextDocument(newUri)).getText(), 'FOOBAR');
+		assert.equal((await vscode.workspace.openTextDocument(anotherFile)).getText(), 'FARBOO');
+	});
+});
diff --git a/src/vs/vscode.proposed.d.ts b/src/vs/vscode.proposed.d.ts
index 0000ccf457c5dc805b59b71a96d9546fd09832fe..b2dfc272b5720f81d2a0666e825227c7522b148b 100644
--- a/src/vs/vscode.proposed.d.ts
+++ b/src/vs/vscode.proposed.d.ts
@@ -733,7 +733,7 @@ declare module 'vscode' {
 
 	export interface FileWillRenameEvent {
 		readonly renaming: ReadonlyArray<{ oldUri: Uri, newUri: Uri }>;
-		waitUntil(thenable: Thenable<WorkspaceEdit>): void;
+		waitUntil(thenable: Thenable<WorkspaceEdit>): void; // TODO@joh support sync/async
 	}
 
 	export namespace workspace {
diff --git a/src/vs/workbench/api/common/extHostFileSystemEventService.ts b/src/vs/workbench/api/common/extHostFileSystemEventService.ts
index bb0e51045a3f92ed6d155e0443151c0fd3370ade..a290fb0cc0f3c04f862878cc0312e87530c1bcfa 100644
--- a/src/vs/workbench/api/common/extHostFileSystemEventService.ts
+++ b/src/vs/workbench/api/common/extHostFileSystemEventService.ts
@@ -142,7 +142,7 @@ export class ExtHostFileSystemEventService implements ExtHostFileSystemEventServ
 	$onDidRunFileOperation(operation: FileOperation, target: UriComponents, source: UriComponents | undefined): void {
 		switch (operation) {
 			case FileOperation.MOVE:
-				this._onDidRenameFile.fire(Object.freeze({ renamed: [{ oldUri: URI.revive(target), newUri: URI.revive(source!) }] }));
+				this._onDidRenameFile.fire(Object.freeze({ renamed: [{ oldUri: URI.revive(source!), newUri: URI.revive(target) }] }));
 				break;
 			case FileOperation.DELETE:
 				this._onDidDeleteFile.fire(Object.freeze({ deleted: [URI.revive(target)] }));
@@ -179,7 +179,7 @@ export class ExtHostFileSystemEventService implements ExtHostFileSystemEventServ
 	async $onWillRunFileOperation(operation: FileOperation, target: UriComponents, source: UriComponents | undefined): Promise<any> {
 		switch (operation) {
 			case FileOperation.MOVE:
-				await this._fireWillRename(URI.revive(target), URI.revive(source!));
+				await this._fireWillRename(URI.revive(source!), URI.revive(target));
 				break;
 			case FileOperation.DELETE:
 				this._onWillDeleteFile.fireAsync(thenables => (<vscode.FileWillDeleteEvent>{ deleting: [URI.revive(target)], waitUntil: p => thenables.push(Promise.resolve(p)) }));