fix(toolkit-lib): remove deprecated outdir option from watch (#313)

The watch functionality has been updated to:
1. Remove the deprecated outdir parameter from WatchOptions
2. Use assembly.directory instead of the hardcoded 'cdk.out' default
3. Only exclude the outdir from watching if it's under the root
directory
4. Update tests to reflect these changes


BREAKING CHANGE: The `outdir` option in `WatchOptions` was deprecated
and has been removed. Instead, the code now determines the assembly
directory directly. To explicitly restore the previous behavior, you add
the value to `WatchOptions.exclude`.

---
By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache-2.0 license

Author: mrgrain

packages/@aws-cdk/toolkit-lib/lib/actions/watch/index.ts

@@ -21,13 +21,4 @@ export interface WatchOptions extends BaseDeployOptions {
    * @default process.cwd()
    */
   readonly watchDir?: string;
-
-  /**
-   * The output directory to write CloudFormation template to
-   *
-   * @deprecated this should be grabbed from the cloud assembly itself
-   *
-   * @default 'cdk.out'
-   */
-  readonly outdir?: string;
 }

packages/@aws-cdk/toolkit-lib/lib/toolkit/toolkit.ts

@@ -760,11 +760,19 @@ export class Toolkit extends CloudAssemblySourceBuilder {
     // 2. Any file whose name starts with a dot.
     // 3. Any directory's content whose name starts with a dot.
     // 4. Any node_modules and its content (even if it's not a JS/TS project, you might be using a local aws-cli package)
-    const outdir = options.outdir ?? 'cdk.out';
+    const outdir = assembly.directory;
     const watchExcludes = patternsArrayForWatch(options.exclude, {
       rootDir,
       returnRootDirIfEmpty: false,
-    }).concat(`${outdir}/**`, '**/.*', '**/.*/**', '**/node_modules/**');
+    });
+
+    // only exclude the outdir if it is under the rootDir
+    const relativeOutDir = path.relative(rootDir, outdir);
+    if (Boolean(relativeOutDir && !relativeOutDir.startsWith('..' + path.sep) && !path.isAbsolute(relativeOutDir))) {
+      watchExcludes.push(`${relativeOutDir}/**`);
+    }
+
+    watchExcludes.push('**/.*', '**/.*/**', '**/node_modules/**');
 
     // Print some debug information on computed settings
     await ioHelper.notify(IO.CDK_TOOLKIT_I5310.msg([

packages/@aws-cdk/toolkit-lib/test/actions/watch.test.ts

@@ -39,6 +39,7 @@ jest.mock('chokidar', () => ({
   watch: mockChokidarWatch,
 }));
 
+import * as path from 'node:path';
 import { HotswapMode } from '../../lib';
 import { Toolkit } from '../../lib/toolkit';
 import { builderFixture, TestIoHost } from '../_helpers';
@@ -80,7 +81,7 @@ describe('watch', () => {
     }));
   });
 
-  test('ignores output dir, dot files, dot directories, node_modules by default', async () => {
+  test('dot files, dot directories, node_modules by default', async () => {
     // WHEN
     const cx = await builderFixture(toolkit, 'stack-with-role');
     ioHost.level = 'debug';
@@ -92,7 +93,30 @@ describe('watch', () => {
     expect(ioHost.notifySpy).toHaveBeenCalledWith(expect.objectContaining({
       action: 'watch',
       level: 'debug',
-      message: expect.stringContaining('\'exclude\' patterns for \'watch\': ["cdk.out/**","**/.*","**/.*/**","**/node_modules/**"]'),
+      code: 'CDK_TOOLKIT_I5310',
+      message: expect.stringContaining('\'exclude\' patterns for \'watch\': ["**/.*","**/.*/**","**/node_modules/**"]'),
+    }));
+  });
+
+  test('ignores outdir when under the watch dir', async () => {
+    // WHEN
+    const cx = await builderFixture(toolkit, 'stack-with-role');
+    const assembly = await toolkit.synth(cx);
+    const outdir = (await assembly.produce()).directory;
+    const watchDir = path.normalize(outdir + path.sep + '..');
+
+    ioHost.level = 'debug';
+    await toolkit.watch(assembly, {
+      watchDir,
+      exclude: [],
+    });
+
+    // THEN
+    expect(ioHost.notifySpy).toHaveBeenCalledWith(expect.objectContaining({
+      action: 'watch',
+      level: 'debug',
+      code: 'CDK_TOOLKIT_I5310',
+      message: expect.stringContaining(`'exclude' patterns for 'watch': ["${path.basename(outdir)}/**","**/.*","**/.*/**","**/node_modules/**"]`),
     }));
   });