fix(cli): remove source maps

packages/aws-cdk/CONTRIBUTING.md

@@ -257,3 +257,20 @@ will change, and needs to be regenerated. For you, this means that:
 2. When you build the CLI locally, you must ensure your dependencies are up to date by running `yarn install` inside the CLI package.
 Otherwise, you might get an error like so: `aws-cdk: - [bundle/outdated-attributions] THIRD_PARTY_LICENSES is outdated (fixable)`.
 
+## Source Maps
+
+The source map handling is not entirely intuitive, so it bears some description here.
+
+There are 2 steps to producing a CLI build:
+
+- First we compile TypeScript to JavaScript. This step is configured to produce inline sourcemaps.
+- Then we bundle JavaScript -> bundled JavaScript. This removes the inline
+  sourcemaps, and also is configured to *not* emit a fresh sourcemap file.
+
+The upshot is that we don't vend a 30+MB sourcemap to customers that they have no use for,
+and that we don't slow down Node loading those sourcemaps, while if we are locally developing
+and testing the sourcemaps are still present and can be used.
+
+During the CLI initialization, we always enable source map support: if we are developing
+then source maps are present and can be used, while in a production build there will be no
+source maps so there's nothing to load anyway.

packages/aws-cdk/bin/cdk

@@ -1,7 +1,6 @@
 #!/usr/bin/env node
 
 // source maps must be enabled before importing files
-if (process.argv.includes('--debug')) {
-  process.setSourceMapsEnabled(true);
-}
+process.setSourceMapsEnabled(true);
+
 require('./cdk.js');

packages/aws-cdk/lib/cli.ts

@@ -559,6 +559,7 @@ function determineHotswapMode(hotswap?: boolean, hotswapFallback?: boolean, watc
   return hotswapMode;
 }
 
+/* istanbul ignore next: we never call this in unit tests */
 export function cli(args: string[] = process.argv.slice(2)) {
   exec(args)
     .then(async (value) => {
@@ -568,7 +569,10 @@ export function cli(args: string[] = process.argv.slice(2)) {
     })
     .catch((err) => {
       error(err.message);
-      if (err.stack) {
+
+      // Log the stack trace if we're on a developer workstation. Otherwise this will be into a minified
+      // file and the printed code line and stack trace are huge and useless.
+      if (err.stack && version.isDeveloperBuild()) {
         debug(err.stack);
       }
       process.exitCode = 1;

packages/aws-cdk/lib/config.ts

@@ -21,7 +21,7 @@ export function makeConfig(): CliConfig {
       'ignore-errors': { type: 'boolean', default: false, desc: 'Ignores synthesis errors, which will likely produce an invalid output' },
       'json': { type: 'boolean', alias: 'j', desc: 'Use JSON output instead of YAML when templates are printed to STDOUT', default: false },
       'verbose': { type: 'boolean', alias: 'v', desc: 'Show debug logs (specify multiple times to increase verbosity)', default: false, count: true },
-      'debug': { type: 'boolean', desc: 'Enable emission of additional debugging information, such as creation stack traces of tokens', default: false },
+      'debug': { type: 'boolean', desc: 'Debug the CDK app. Log additional information during synthesis, such as creation stack traces of tokens (sets CDK_DEBUG, will slow down synthesis)', default: false },
       'profile': { type: 'string', desc: 'Use the indicated AWS profile as the default environment', requiresArg: true },
       'proxy': { type: 'string', desc: 'Use the indicated proxy. Will read from HTTPS_PROXY environment variable if not specified', requiresArg: true },
       'ca-bundle-path': { type: 'string', desc: 'Path to CA certificate to use when validating HTTPS requests. Will read from AWS_CA_BUNDLE environment variable if not specified', requiresArg: true },

packages/aws-cdk/lib/parse-command-line-arguments.ts

@@ -73,7 +73,7 @@ export function parseCommandLineArguments(
     })
     .option('debug', {
       type: 'boolean',
-      desc: 'Enable emission of additional debugging information, such as creation stack traces of tokens',
+      desc: 'Debug the CDK app. Log additional information during synthesis, such as creation stack traces of tokens (sets CDK_DEBUG, will slow down synthesis)',
       default: false,
     })
     .option('profile', {

packages/aws-cdk/lib/version.ts

@@ -15,6 +15,10 @@ const UPGRADE_DOCUMENTATION_LINKS: Record<number, string> = {
 
 export const DISPLAY_VERSION = `${versionNumber()} (build ${commit()})`;
 
+export function isDeveloperBuild(): boolean {
+  return versionNumber() === '0.0.0';
+}
+
 export function versionNumber(): string {
   // eslint-disable-next-line @typescript-eslint/no-require-imports
   return require(path.join(rootDir(), 'package.json')).version.replace(/\+[0-9a-f]+$/, '');

packages/aws-cdk/package.json

@@ -57,7 +57,6 @@
       "entryPoints": [
         "lib/index.js"
       ],
-      "sourcemap": "linked",
       "minifyWhitespace": true
     }
   },

packages/aws-cdk/test/version.test.ts

@@ -7,7 +7,7 @@ import * as os from 'os';
 import * as sinon from 'sinon';
 import * as logging from '../lib/logging';
 import * as npm from '../lib/util/npm';
-import { latestVersionIfHigher, VersionCheckTTL, displayVersionMessage } from '../lib/version';
+import { latestVersionIfHigher, VersionCheckTTL, displayVersionMessage, isDeveloperBuild } from '../lib/version';
 
 jest.setTimeout(10_000);
 
@@ -141,3 +141,13 @@ describe('version message', () => {
     expect(printSpy).not.toHaveBeenCalledWith(expect.stringContaining('Information about upgrading from 99.x to 100.x'));
   });
 });
+
+test('isDeveloperBuild call does not throw an error', () => {
+  // To be frank: this is just to shut CodeCov up. It don't want to make an assertion
+  // that the value is `true` when running tests, because I won't want to make too
+  // many assumptions for no good reason.
+
+  isDeveloperBuild();
+
+  // THEN: should not explode
+});

tools/@aws-cdk/node-bundle/src/api/bundle.ts

@@ -443,7 +443,7 @@ export class Bundle {
       bundle: true,
       target: 'node14',
       platform: 'node',
-      sourcemap: this.sourcemap ?? 'inline',
+      sourcemap: this.sourcemap,
       metafile: true,
       minify: this.minify,
       minifyWhitespace: this.minifyWhitespace,