chore(toolkit): capture all output from an app (#33259)

### Issue #32997

Relates to #32997

### Reason for this change

When a CDK app is invoked by a sub-shell, we need to capture all output
by lines and send it to the IoHost.

### Description of changes

Adds an `EventPublisher` interface to the `execInChildProcess` helper.
This is getting passed in a publisher that uses the IoHost.
Inspired from the [ShellEventPublisher in
cdk-assets](https://github.com/cdklabs/cdk-assets/blame/8751d206ea3fa6dbb6156125c64d0ea0e8df289e/lib/private/shell.ts#L6).

### Describe any new or updated permissions being added

n/a

### Description of how you validated changes

<!--Have you added any unit tests and/or integration tests?-->

### Checklist
- [x] My code adheres to the [CONTRIBUTING
GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and
[DESIGN
GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

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

---------

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

packages/@aws-cdk/toolkit/lib/api/cloud-assembly/private/exec.ts

@@ -1,7 +1,11 @@
 import * as child_process from 'node:child_process';
+import * as split2 from 'split2';
 import { ToolkitError } from '../../errors';
 
+type EventPublisher = (event: 'open' | 'data_stdout' | 'data_stderr' | 'close', line: string) => void;
+
 interface ExecOptions {
+  eventPublisher?: EventPublisher;
   extraEnv?: { [key: string]: string | undefined };
   cwd?: string;
 }
@@ -17,12 +21,10 @@ export async function execInChildProcess(commandAndArgs: string, options: ExecOp
     //   number of quoting issues introduced by the intermediate shell layer
     //   (which would be different between Linux and Windows).
     //
-    // - Inherit stderr from controlling terminal. We don't use the captured value
-    //   anyway, and if the subprocess is printing to it for debugging purposes the
-    //   user gets to see it sooner. Plus, capturing doesn't interact nicely with some
-    //   processes like Maven.
+    // - We have to capture any output to stdout and stderr sp we can pass it on to the IoHost
+    //   To ensure messages get to the user fast, we will emit every full line we receive.
     const proc = child_process.spawn(commandAndArgs, {
-      stdio: ['ignore', 'inherit', 'inherit'],
+      stdio: ['ignore', 'pipe', 'pipe'],
       detached: false,
       shell: true,
       cwd: options.cwd,
@@ -32,6 +34,22 @@ export async function execInChildProcess(commandAndArgs: string, options: ExecOp
       },
     });
 
+    const eventPublisher: EventPublisher = options.eventPublisher ?? ((type, line) => {
+      switch (type) {
+        case 'data_stdout':
+          process.stdout.write(line);
+          return;
+        case 'data_stderr':
+          process.stderr.write(line);
+          return;
+        case 'open':
+        case 'close':
+          return;
+      }
+    });
+    proc.stdout.pipe(split2()).on('data', (line) => eventPublisher('data_stdout', line));
+    proc.stderr.pipe(split2()).on('data', (line) => eventPublisher('data_stderr', line));
+
     proc.on('error', fail);
 
     proc.on('exit', code => {

packages/@aws-cdk/toolkit/lib/api/cloud-assembly/private/source-builder.ts

@@ -7,15 +7,15 @@ import { assemblyFromDirectory, changeDir, determineOutputDirectory, guessExecut
 import { ToolkitServices } from '../../../toolkit/private';
 import { Context, ILock, RWLock, Settings } from '../../aws-cdk';
 import { ToolkitError } from '../../errors';
-import { debug } from '../../io/private';
+import { debug, error, info } from '../../io/private';
 import { AssemblyBuilder, CdkAppSourceProps } from '../source-builder';
 
 export abstract class CloudAssemblySourceBuilder {
   /**
    * Helper to provide the CloudAssemblySourceBuilder with required toolkit services
    * @deprecated this should move to the toolkit really.
    */
-  protected abstract toolkitServices(): Promise<ToolkitServices>;
+  protected abstract sourceBuilderServices(): Promise<ToolkitServices>;
 
   /**
    * Create a Cloud Assembly from a Cloud Assembly builder function.
@@ -27,7 +27,7 @@ export abstract class CloudAssemblySourceBuilder {
     builder: AssemblyBuilder,
     props: CdkAppSourceProps = {},
   ): Promise<ICloudAssemblySource> {
-    const services = await this.toolkitServices();
+    const services = await this.sourceBuilderServices();
     const context = new Context({ bag: new Settings(props.context ?? {}) });
     const contextAssemblyProps: ContextAwareCloudAssemblyProps = {
       services,
@@ -65,7 +65,7 @@ export abstract class CloudAssemblySourceBuilder {
    * @returns the CloudAssembly source
    */
   public async fromAssemblyDirectory(directory: string): Promise<ICloudAssemblySource> {
-    const services: ToolkitServices = await this.toolkitServices();
+    const services: ToolkitServices = await this.sourceBuilderServices();
     const contextAssemblyProps: ContextAwareCloudAssemblyProps = {
       services,
       context: new Context(), // @todo there is probably a difference between contextaware and contextlookup sources
@@ -89,7 +89,7 @@ export abstract class CloudAssemblySourceBuilder {
    * @returns the CloudAssembly source
    */
   public async fromCdkApp(app: string, props: CdkAppSourceProps = {}): Promise<ICloudAssemblySource> {
-    const services: ToolkitServices = await this.toolkitServices();
+    const services: ToolkitServices = await this.sourceBuilderServices();
     // @todo this definitely needs to read files from the CWD
     const context = new Context({ bag: new Settings(props.context ?? {}) });
     const contextAssemblyProps: ContextAwareCloudAssemblyProps = {
@@ -122,7 +122,20 @@ export abstract class CloudAssemblySourceBuilder {
 
             const env = await prepareDefaultEnvironment(services, { outdir });
             return await withContext(context.all, env, props.synthOptions, async (envWithContext, _ctx) => {
-              await execInChildProcess(commandLine.join(' '), { extraEnv: envWithContext, cwd: props.workingDirectory });
+              await execInChildProcess(commandLine.join(' '), {
+                eventPublisher: async (type, line) => {
+                  switch (type) {
+                    case 'data_stdout':
+                      await services.ioHost.notify(info(line, 'CDK_ASSEMBLY_I1001'));
+                      break;
+                    case 'data_stderr':
+                      await services.ioHost.notify(error(line, 'CDK_ASSEMBLY_E1002'));
+                      break;
+                  }
+                },
+                extraEnv: envWithContext,
+                cwd: props.workingDirectory,
+              });
               return assemblyFromDirectory(outdir, services.ioHost);
             });
           } finally {

packages/@aws-cdk/toolkit/lib/api/io/private/codes.ts

@@ -1,20 +1,6 @@
 import { IoMessageCode } from '../io-message';
 
 export const CODES = {
-  // Default codes -- all 0000 codes
-  CDK_TOOLKIT_I0000: 'Default toolkit info code',
-  CDK_TOOLKIT_E0000: 'Default toolkit error code',
-  CDK_TOOLKIT_W0000: 'Default toolkit warning code',
-  CDK_SDK_I0000: 'Default sdk info code',
-  CDK_SDK_E0000: 'Default sdk error code',
-  CDK_SDK_WOOOO: 'Default sdk warning code',
-  CDK_ASSETS_I0000: 'Default assets info code',
-  CDK_ASSETS_E0000: 'Default assets error code',
-  CDK_ASSETS_W0000: 'Default assets warning code',
-  CDK_ASSEMBLY_I0000: 'Default assembly info code',
-  CDK_ASSEMBLY_E0000: 'Default assembly error code',
-  CDK_ASSEMBLY_W0000: 'Default assembly warning code',
-
   // Toolkit Info codes
   CDK_TOOLKIT_I0001: 'Display stack data',
   CDK_TOOLKIT_I0002: 'Successfully deployed stacks',
@@ -31,10 +17,10 @@ export const CODES = {
   // Assembly Info codes
   CDK_ASSEMBLY_I0042: 'Writing updated context',
   CDK_ASSEMBLY_I0241: 'Fetching missing context',
-
-  // Assembly Warning codes
-
-  // Assembly Error codes
+  CDK_ASSEMBLY_I1000: 'Cloud assembly output starts',
+  CDK_ASSEMBLY_I1001: 'Output lines emitted by the cloud assembly to stdout',
+  CDK_ASSEMBLY_E1002: 'Output lines emitted by the cloud assembly to stderr',
+  CDK_ASSEMBLY_I1003: 'Cloud assembly output finished',
   CDK_ASSEMBLY_E1111: 'Incompatible CDK CLI version. Upgrade needed.',
 };
 

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

@@ -56,7 +56,7 @@ export interface ToolkitOptions {
 
   /**
    * Whether to allow ANSI colors and formatting in IoHost messages.
-   * Setting this value to `falsez enforces that no color or style shows up
+   * Setting this value to `false` enforces that no color or style shows up
    * in messages sent to the IoHost.
    * Setting this value to true is a no-op; it is equivalent to the default.
    *
@@ -144,9 +144,9 @@ export class Toolkit extends CloudAssemblySourceBuilder implements AsyncDisposab
   /**
    * Helper to provide the CloudAssemblySourceBuilder with required toolkit services
    */
-  protected override async toolkitServices(): Promise<ToolkitServices> {
+  protected override async sourceBuilderServices(): Promise<ToolkitServices> {
     return {
-      ioHost: this.ioHost,
+      ioHost: withAction(this.ioHost, 'assembly'),
       sdkProvider: await this.sdkProvider('assembly'),
     };
   }

packages/@aws-cdk/toolkit/package.json

@@ -49,6 +49,7 @@
     "@types/fs-extra": "^9.0.13",
     "@types/jest": "^29.5.14",
     "@types/node": "^18.18.14",
+    "@types/split2": "^4.2.3",
     "aws-cdk": "0.0.0",
     "aws-cdk-lib": "0.0.0",
     "aws-sdk-client-mock": "^4.0.1",
@@ -105,6 +106,7 @@
     "promptly": "^3.2.0",
     "proxy-agent": "^6.4.0",
     "semver": "^7.6.3",
+    "split2": "^4.2.0",
     "strip-ansi": "^6.0.1",
     "table": "^6.8.2",
     "uuid": "^8.3.2",

packages/@aws-cdk/toolkit/test/_fixtures/console-output/app.js

@@ -0,0 +1,9 @@
+import * as cdk from 'aws-cdk-lib/core';
+
+console.log('line one');
+const app = new cdk.App();
+console.log('line two');
+new cdk.Stack(app, 'Stack1');
+console.log('line three');
+app.synth();
+console.log('line four');

packages/@aws-cdk/toolkit/test/_fixtures/validation-error/app.js

@@ -0,0 +1,11 @@
+import * as cdk from 'aws-cdk-lib/core';
+import * as sqs from 'aws-cdk-lib/aws-sqs';
+
+const app = new cdk.App();
+const stack = new cdk.Stack(app, 'Stack1');
+new sqs.Queue(stack, 'Queue1', {
+  queueName: "Queue1",
+  fifo: true,
+});
+
+app.synth();

packages/@aws-cdk/toolkit/test/api/cloud-assembly/source-builder.test.ts

@@ -53,6 +53,38 @@ describe('fromCdkApp', () => {
     // THEN
     expect(JSON.stringify(stack)).toContain('amzn-s3-demo-bucket');
   });
+
+  test('will capture error output', async () => {
+    // WHEN
+    const cx = await appFixture(toolkit, 'validation-error');
+    try {
+      await cx.produce();
+    } catch {
+      // we are just interested in the output for this test
+    }
+
+    // THEN
+    expect(ioHost.notifySpy).toHaveBeenCalledWith(expect.objectContaining({
+      level: 'error',
+      code: 'CDK_ASSEMBLY_E1002',
+      message: expect.stringContaining('ValidationError'),
+    }));
+  });
+
+  test('will capture all output', async () => {
+    // WHEN
+    const cx = await appFixture(toolkit, 'console-output');
+    await cx.produce();
+
+    // THEN
+    ['one', 'two', 'three', 'four'].forEach((line) => {
+      expect(ioHost.notifySpy).toHaveBeenCalledWith(expect.objectContaining({
+        level: 'info',
+        code: 'CDK_ASSEMBLY_I1001',
+        message: `line ${line}`,
+      }));
+    });
+  });
 });
 
 describe('fromAssemblyDirectory', () => {

packages/aws-cdk/lib/toolkit/cli-io-host.ts

@@ -79,6 +79,7 @@ export const levelPriority: Record<IoMessageLevel, number> = {
  * The current action being performed by the CLI. 'none' represents the absence of an action.
  */
 export type ToolkitAction =
+| 'assembly'
 | 'bootstrap'
 | 'synth'
 | 'list'

yarn.lock

@@ -9422,6 +9422,13 @@
   resolved "https://registry.npmjs.org/@types/sinonjs__fake-timers/-/sinonjs__fake-timers-8.1.5.tgz#5fd3592ff10c1e9695d377020c033116cc2889f2"
   integrity sha512-mQkU2jY8jJEF7YHjHvsQO8+3ughTL1mcnn96igfhONmR+fUPSKIkefQYpSe8bsly2Ep7oQbn/6VG5/9/0qcArQ==
 
+"@types/split2@^4.2.3":
+  version "4.2.3"
+  resolved "https://registry.npmjs.org/@types/split2/-/split2-4.2.3.tgz#ddd9b6b8518df6e0a7825851fcd98de12e415f0b"
+  integrity sha512-59OXIlfUsi2k++H6CHgUQKEb2HKRokUA39HY1i1dS8/AIcqVjtAAFdf8u+HxTWK/4FUHMJQlKSZ4I6irCBJ1Zw==
+  dependencies:
+    "@types/node" "*"
+
 "@types/stack-utils@^2.0.0":
   version "2.0.3"
   resolved "https://registry.npmjs.org/@types/stack-utils/-/stack-utils-2.0.3.tgz#6209321eb2c1712a7e7466422b8cb1fc0d9dd5d8"
@@ -19005,6 +19012,11 @@ split2@^3.0.0, split2@^3.2.2:
   dependencies:
     readable-stream "^3.0.0"
 
+split2@^4.2.0:
+  version "4.2.0"
+  resolved "https://registry.npmjs.org/split2/-/split2-4.2.0.tgz#c9c5920904d148bab0b9f67145f245a86aadbfa4"
+  integrity sha512-UcjcJOWknrNkF6PLX83qcHM6KHgVKNkV62Y8a5uYDVv9ydGQVwAHMKqHdJje1VTWpljG0WYpCDhrCdAOYH4TWg==
+
 split@^1.0.0, split@^1.0.1:
   version "1.0.1"
   resolved "https://registry.npmjs.org/split/-/split-1.0.1.tgz#605bd9be303aa59fb35f9229fbea0ddec9ea07d9"