refactor(@angular-devkit/build-angular): assert catch clause variable type before usage

Prepares the `@angular-devkit/build-angular` package for the eventual change of enabling the
TypeScript `useUnknownInCatchVariables` option. This option provides additional
code safety by ensuring that the catch clause variable is the proper type before
attempting to access its properties. Similar changes will be needed in the other
packages in the repository prior to enabling `useUnknownInCatchVariables`.

Author: clydin

packages/angular_devkit/build_angular/src/builders/app-shell/index.ts

@@ -16,6 +16,7 @@ import { JsonObject } from '@angular-devkit/core';
 import * as fs from 'fs';
 import * as path from 'path';
 import { normalizeOptimization } from '../../utils';
+import { assertIsError } from '../../utils/error';
 import { InlineCriticalCssProcessor } from '../../utils/index-file/inline-critical-css';
 import { augmentAppWithServiceWorker } from '../../utils/service-worker';
 import { Spinner } from '../../utils/spinner';
@@ -199,6 +200,7 @@ async function _appShellBuilder(
     return result;
   } catch (err) {
     spinner?.fail('Application shell generation failed.');
+    assertIsError(err);
 
     return { success: false, error: err.message };
   } finally {

packages/angular_devkit/build_angular/src/builders/browser-esbuild/index.ts

@@ -13,6 +13,7 @@ import { promises as fs } from 'fs';
 import * as path from 'path';
 import { NormalizedOptimizationOptions, deleteOutputDir } from '../../utils';
 import { copyAssets } from '../../utils/copy-assets';
+import { assertIsError } from '../../utils/error';
 import { FileInfo } from '../../utils/index-file/augment-index-html';
 import { IndexHtmlGenerator } from '../../utils/index-file/index-html-generator';
 import { generateEntryPoints } from '../../utils/package-chunk-sort';
@@ -134,8 +135,8 @@ export async function execute(
   try {
     await fs.mkdir(outputPath, { recursive: true });
   } catch (e) {
-    const reason = 'message' in e ? e.message : 'Unknown error';
-    context.logger.error('Unable to create output directory: ' + reason);
+    assertIsError(e);
+    context.logger.error('Unable to create output directory: ' + e.message);
 
     return { success: false };
   }

packages/angular_devkit/build_angular/src/builders/browser/index.ts

@@ -29,6 +29,7 @@ import {
 } from '../../utils/bundle-calculator';
 import { colors } from '../../utils/color';
 import { copyAssets } from '../../utils/copy-assets';
+import { assertIsError } from '../../utils/error';
 import { i18nInlineEmittedFiles } from '../../utils/i18n-inlining';
 import { I18nOptions } from '../../utils/i18n-options';
 import { FileInfo } from '../../utils/index-file/augment-index-html';
@@ -278,6 +279,7 @@ export function buildWebpackBrowser(
                     spinner.succeed('Copying assets complete.');
                   } catch (err) {
                     spinner.fail(colors.redBright('Copying of assets failed.'));
+                    assertIsError(err);
 
                     return { success: false, error: 'Unable to copy assets: ' + err.message };
                   }

packages/angular_devkit/build_angular/src/builders/protractor/index.ts

@@ -16,6 +16,7 @@ import { json, tags } from '@angular-devkit/core';
 import { resolve } from 'path';
 import * as url from 'url';
 import { runModuleAsObservableFork } from '../../utils';
+import { assertIsError } from '../../utils/error';
 import { DevServerBuilderOptions } from '../dev-server/index';
 import { Schema as ProtractorBuilderOptions } from './schema';
 
@@ -56,6 +57,7 @@ async function updateWebdriver() {
 
     path = require.resolve(webdriverDeepImport, { paths: [protractorPath] });
   } catch (error) {
+    assertIsError(error);
     if (error.code !== 'MODULE_NOT_FOUND') {
       throw error;
     }

packages/angular_devkit/build_angular/src/sass/worker.ts

@@ -60,7 +60,8 @@ parentPort.on('message', ({ id, hasImporter, options }: RenderRequestMessage) =>
     const result = renderSync(options);
 
     parentPort?.postMessage({ id, result });
-  } catch (error) {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  } catch (error: any) {
     // Needed because V8 will only serialize the message and stack properties of an Error instance.
     const { formatted, file, line, column, message, stack } = error;
     parentPort?.postMessage({ id, error: { formatted, file, line, column, message, stack } });

packages/angular_devkit/build_angular/src/testing/jasmine-helpers.ts

@@ -95,7 +95,7 @@ export function expectFile<T>(path: string, harness: BuilderHarness<T>): Harness
       try {
         return expect(harness.readFile(path)).withContext(`With file content for '${path}'`);
       } catch (e) {
-        if (e.code !== 'ENOENT') {
+        if ((e as NodeJS.ErrnoException).code !== 'ENOENT') {
           throw e;
         }
 
@@ -112,7 +112,7 @@ export function expectFile<T>(path: string, harness: BuilderHarness<T>): Harness
           `With file size for '${path}'`,
         );
       } catch (e) {
-        if (e.code !== 'ENOENT') {
+        if ((e as NodeJS.ErrnoException).code !== 'ENOENT') {
           throw e;
         }
 

packages/angular_devkit/build_angular/src/utils/error.ts

@@ -0,0 +1,13 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import assert from 'assert';
+
+export function assertIsError(value: unknown): asserts value is Error & { code?: string } {
+  assert(value instanceof Error, 'catch clause variable is not an Error instance');
+}

packages/angular_devkit/build_angular/src/utils/i18n-inlining.ts

@@ -12,6 +12,7 @@ import * as fs from 'fs';
 import * as path from 'path';
 import { BundleActionExecutor } from './action-executor';
 import { copyAssets } from './copy-assets';
+import { assertIsError } from './error';
 import { I18nOptions } from './i18n-options';
 import { InlineOptions } from './process-bundle';
 import { Spinner } from './spinner';
@@ -52,6 +53,7 @@ function emittedFilesToInlineOptions(
       action.map = fs.readFileSync(originalMapPath, 'utf8');
       originalFiles.push(originalMapPath);
     } catch (err) {
+      assertIsError(err);
       if (err.code !== 'ENOENT') {
         throw err;
       }
@@ -121,6 +123,7 @@ export async function i18nInlineEmittedFiles(
       '',
     );
   } catch (err) {
+    assertIsError(err);
     spinner.fail('Localized bundle generation failed: ' + err.message);
 
     return false;

packages/angular_devkit/build_angular/src/utils/process-bundle.ts

@@ -21,6 +21,7 @@ import * as fs from 'fs';
 import * as path from 'path';
 import { workerData } from 'worker_threads';
 import { allowMinify, shouldBeautify } from './environment-options';
+import { assertIsError } from './error';
 import { I18nOptions } from './i18n-options';
 import { loadEsmModule } from './load-esm';
 
@@ -151,14 +152,14 @@ export async function inlineLocales(options: InlineOptions) {
       filename: options.filename,
     });
   } catch (error) {
-    if (error.message) {
-      // Make the error more readable.
-      // Same errors will contain the full content of the file as the error message
-      // Which makes it hard to find the actual error message.
-      const index = error.message.indexOf(')\n');
-      const msg = index !== -1 ? error.message.slice(0, index + 1) : error.message;
-      throw new Error(`${msg}\nAn error occurred inlining file "${options.filename}"`);
-    }
+    assertIsError(error);
+
+    // Make the error more readable.
+    // Same errors will contain the full content of the file as the error message
+    // Which makes it hard to find the actual error message.
+    const index = error.message.indexOf(')\n');
+    const msg = index !== -1 ? error.message.slice(0, index + 1) : error.message;
+    throw new Error(`${msg}\nAn error occurred inlining file "${options.filename}"`);
   }
 
   if (!ast) {

packages/angular_devkit/build_angular/src/utils/service-worker.ts

@@ -11,6 +11,7 @@ import * as crypto from 'crypto';
 import { createReadStream, promises as fs, constants as fsConstants } from 'fs';
 import * as path from 'path';
 import { pipeline } from 'stream';
+import { assertIsError } from './error';
 import { loadEsmModule } from './load-esm';
 
 class CliFilesystem implements Filesystem {
@@ -78,6 +79,7 @@ export async function augmentAppWithServiceWorker(
     const configurationData = await fs.readFile(configPath, 'utf-8');
     config = JSON.parse(configurationData) as Config;
   } catch (error) {
+    assertIsError(error);
     if (error.code === 'ENOENT') {
       throw new Error(
         'Error: Expected to find an ngsw-config.json configuration file' +
@@ -130,6 +132,7 @@ export async function augmentAppWithServiceWorker(
       fsConstants.COPYFILE_FICLONE,
     );
   } catch (error) {
+    assertIsError(error);
     if (error.code !== 'ENOENT') {
       throw error;
     }

packages/angular_devkit/build_angular/src/webpack/configs/dev-server.ts

@@ -13,6 +13,7 @@ import { URL, pathToFileURL } from 'url';
 import { Configuration, RuleSetRule } from 'webpack';
 import { Configuration as DevServerConfiguration } from 'webpack-dev-server';
 import { WebpackConfigOptions, WebpackDevServerOptions } from '../../utils/build-options';
+import { assertIsError } from '../../utils/error';
 import { loadEsmModule } from '../../utils/load-esm';
 import { getIndexOutputFile } from '../../utils/webpack-browser-config';
 import { HmrLoader } from '../plugins/hmr/hmr-loader';
@@ -193,6 +194,7 @@ async function addProxyConfig(root: string, proxyConfig: string | undefined) {
       try {
         return require(proxyPath);
       } catch (e) {
+        assertIsError(e);
         if (e.code === 'ERR_REQUIRE_ESM') {
           // Load the ESM configuration file using the TypeScript dynamic import workaround.
           // Once TypeScript provides support for keeping the dynamic import this workaround can be

packages/angular_devkit/build_angular/src/webpack/plugins/index-html-webpack-plugin.ts

@@ -8,6 +8,7 @@
 
 import { basename, dirname, extname } from 'path';
 import { Compilation, Compiler, sources } from 'webpack';
+import { assertIsError } from '../../utils/error';
 import { FileInfo } from '../../utils/index-file/augment-index-html';
 import {
   IndexHtmlGenerator,
@@ -77,6 +78,7 @@ export class IndexHtmlWebpackPlugin extends IndexHtmlGenerator {
         warnings.forEach((msg) => addWarning(this.compilation, msg));
         errors.forEach((msg) => addError(this.compilation, msg));
       } catch (error) {
+        assertIsError(error);
         addError(this.compilation, error.message);
       }
     };

packages/angular_devkit/build_angular/src/webpack/plugins/json-stats-plugin.ts

@@ -9,6 +9,7 @@
 import { createWriteStream, promises as fsPromises } from 'fs';
 import { dirname } from 'path';
 import { Compiler } from 'webpack';
+import { assertIsError } from '../../utils/error';
 
 import { addError } from '../../utils/webpack-diagnostics';
 
@@ -29,6 +30,7 @@ export class JsonStatsPlugin {
             .on('error', reject),
         );
       } catch (error) {
+        assertIsError(error);
         addError(
           stats.compilation,
           `Unable to write stats file: ${error.message || 'unknown error'}`,

packages/angular_devkit/build_angular/src/webpack/plugins/postcss-cli-resources.ts

@@ -10,6 +10,7 @@ import { interpolateName } from 'loader-utils';
 import * as path from 'path';
 import { Declaration, Plugin } from 'postcss';
 import * as url from 'url';
+import { assertIsError } from '../../utils/error';
 
 function wrapUrl(url: string): string {
   let wrappedUrl;
@@ -172,6 +173,7 @@ export default function (options?: PostcssCliResourcesOptions): Plugin {
         try {
           processedUrl = await process(originalUrl, context, resourceCache);
         } catch (err) {
+          assertIsError(err);
           loader.emitError(decl.error(err.message, { word: originalUrl }));
           continue;
         }