Fix flaky WordPress server startup test

Author: shaunandrews

apps/cli/lib/tests/wordpress-server-manager.test.ts

@@ -97,6 +97,29 @@ describe( 'WordPress Server Manager', () => {
 		} );
 	}
 
+	function mockStartProcessExit( {
+		beforeExit,
+		stderrTail,
+	}: {
+		beforeExit?: () => void;
+		stderrTail?: string;
+	} = {} ): void {
+		vi.mocked( daemonClient.startProcess ).mockImplementation( async () => {
+			setImmediate( () => {
+				beforeExit?.();
+				mockBus.emit( 'process-event', {
+					process: {
+						name: mockProcessDescription.name,
+						pm_id: mockProcessDescription.pmId,
+					},
+					event: 'exit',
+					...( stderrTail ? { stderrTail } : {} ),
+				} );
+			} );
+			return mockProcessDescription;
+		} );
+	}
+
 	describe( 'isServerRunning', () => {
 		it( 'should check if process is running with correct process name', async () => {
 			const mockProcess = {
@@ -264,15 +287,7 @@ describe( 'WordPress Server Manager', () => {
 
 		it( 'should surface an error when the child process exits before becoming ready', async () => {
 			// Do not emit `ready`; instead emit an `exit` event to simulate a crash during startup.
-			setTimeout( () => {
-				mockBus.emit( 'process-event', {
-					process: {
-						name: mockProcessDescription.name,
-						pm_id: mockProcessDescription.pmId,
-					},
-					event: 'exit',
-				} );
-			}, 10 );
+			mockStartProcessExit();
 
 			await expect( startWordPressServer( mockSiteData, mockLogger ) ).rejects.toThrow(
 				/exited before becoming ready/
@@ -281,17 +296,7 @@ describe( 'WordPress Server Manager', () => {
 
 		it( 'should include the child stderr tail in the error when the daemon provides it', async () => {
 			const stderrTail = 'SyntaxError: The requested module did not provide an export named X';
-
-			setTimeout( () => {
-				mockBus.emit( 'process-event', {
-					process: {
-						name: mockProcessDescription.name,
-						pm_id: mockProcessDescription.pmId,
-					},
-					event: 'exit',
-					stderrTail,
-				} );
-			}, 10 );
+			mockStartProcessExit( { stderrTail } );
 
 			await expect( startWordPressServer( mockSiteData, mockLogger ) ).rejects.toThrow(
 				new RegExp( stderrTail.replace( /[.*+?^${}()|[\]\\]/g, '\\$&' ) )
@@ -327,16 +332,11 @@ describe( 'WordPress Server Manager', () => {
 			await fs.promises.mkdir( path.join( sitePath, 'wp-content' ), { recursive: true } );
 			const logPath = path.join( sitePath, 'wp-content', STUDIO_ERROR_LOG_FILENAME );
 
-			setTimeout( () => {
-				fs.writeFileSync( logPath, 'PHP Fatal error: Uncaught Error: Failed opening required' );
-				mockBus.emit( 'process-event', {
-					process: {
-						name: mockProcessDescription.name,
-						pm_id: mockProcessDescription.pmId,
-					},
-					event: 'exit',
-				} );
-			}, 10 );
+			mockStartProcessExit( {
+				beforeExit: () => {
+					fs.writeFileSync( logPath, 'PHP Fatal error: Uncaught Error: Failed opening required' );
+				},
+			} );
 
 			await expect(
 				startWordPressServer( { ...mockSiteData, path: sitePath }, mockLogger )
@@ -350,15 +350,7 @@ describe( 'WordPress Server Manager', () => {
 			const logPath = path.join( sitePath, 'wp-content', 'debug.log' );
 			fs.writeFileSync( logPath, 'PHP Fatal error: from a previous run' );
 
-			setTimeout( () => {
-				mockBus.emit( 'process-event', {
-					process: {
-						name: mockProcessDescription.name,
-						pm_id: mockProcessDescription.pmId,
-					},
-					event: 'exit',
-				} );
-			}, 10 );
+			mockStartProcessExit();
 
 			const error: Error = await startWordPressServer(
 				{ ...mockSiteData, path: sitePath, enableDebugLog: true },
@@ -378,16 +370,11 @@ describe( 'WordPress Server Manager', () => {
 			await fs.promises.mkdir( path.join( sitePath, 'wp-content' ), { recursive: true } );
 			const logPath = path.join( sitePath, 'wp-content', 'debug.log' );
 
-			setTimeout( () => {
-				fs.writeFileSync( logPath, 'PHP Fatal error: Uncaught Error: Failed opening required' );
-				mockBus.emit( 'process-event', {
-					process: {
-						name: mockProcessDescription.name,
-						pm_id: mockProcessDescription.pmId,
-					},
-					event: 'exit',
-				} );
-			}, 10 );
+			mockStartProcessExit( {
+				beforeExit: () => {
+					fs.writeFileSync( logPath, 'PHP Fatal error: Uncaught Error: Failed opening required' );
+				},
+			} );
 
 			await expect(
 				startWordPressServer(