test: assert catch clause variable type before usage in E2E tests

Prepares the E2E tests 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

tests/legacy-cli/e2e/tests/commands/add/add-material.ts

@@ -12,7 +12,7 @@ export default async function () {
   try {
     await ng('add', `@angular/material${tag}`, '--unknown', '--skip-confirmation');
   } catch (error) {
-    if (!(error.message && error.message.includes(`Unknown option: '--unknown'`))) {
+    if (!(error instanceof Error && error.message.includes(`Unknown option: '--unknown'`))) {
       throw error;
     }
   }

tests/legacy-cli/e2e/tests/commands/help/help-json.ts

@@ -52,13 +52,21 @@ export default async function () {
   try {
     JSON.parse(stdout2.trim());
   } catch (error) {
-    throw new Error(`'ng --help ---json-help' failed to return JSON.\n${error.message}`);
+    throw new Error(
+      `'ng --help ---json-help' failed to return JSON.\n${
+        error instanceof Error ? error.message : error
+      }`,
+    );
   }
 
   const { stdout: stdout3 } = await silentNg('generate', '--help', '--json-help');
   try {
     JSON.parse(stdout3.trim());
   } catch (error) {
-    throw new Error(`'ng generate --help ---json-help' failed to return JSON.\n${error.message}`);
+    throw new Error(
+      `'ng generate --help ---json-help' failed to return JSON.\n${
+        error instanceof Error ? error.message : error
+      }`,
+    );
   }
 }

tests/legacy-cli/e2e/tests/commands/unknown-configuration.ts

@@ -5,7 +5,12 @@ export default async function () {
     await ng('build', '--configuration', 'invalid');
     throw new Error('should have failed.');
   } catch (error) {
-    if (!error.message.includes(`Configuration 'invalid' is not set in the workspace`)) {
+    if (
+      !(
+        error instanceof Error &&
+        error.message.includes(`Configuration 'invalid' is not set in the workspace`)
+      )
+    ) {
       throw error;
     }
   }

tests/legacy-cli/e2e/tests/misc/http-headers.ts

@@ -28,7 +28,7 @@ export default async function () {
   try {
     await ng('e2e');
   } catch (error) {
-    errorMessage = error.message;
+    errorMessage = error instanceof Error ? error.message : null;
   }
 
   if (!errorMessage) {

tests/legacy-cli/e2e/tests/test/test-sourcemap.ts

@@ -16,7 +16,7 @@ export default async function () {
     await ng('test', '--no-watch', '--source-map');
     throw new Error('ng test should have failed.');
   } catch (error) {
-    if (!error.message.includes('app.component.spec.ts')) {
+    if (!(error instanceof Error && error.message.includes('app.component.spec.ts'))) {
       throw error;
     }
   }
@@ -26,7 +26,7 @@ export default async function () {
     await ng('test', '--no-watch', '--no-source-map');
     throw new Error('ng test should have failed.');
   } catch (error) {
-    if (!error.message.includes('main.js')) {
+    if (!(error instanceof Error && error.message.includes('main.js'))) {
       throw error;
     }
   }

tests/legacy-cli/e2e/utils/process.ts

@@ -242,7 +242,10 @@ export async function execAndCaptureError(
     await _exec({ env, stdin }, cmd, args);
     throw new Error('Tried to capture subprocess exception, but it completed successfully.');
   } catch (err) {
-    return err;
+    if (err instanceof Error) {
+      return err;
+    }
+    throw new Error('Subprocess exception was not an Error instance');
   }
 }
 

tests/legacy-cli/e2e_runner.ts

@@ -139,9 +139,13 @@ Promise.all([findFreePort(), findFreePort()])
 
       console.log(colors.green('Done.'));
     } catch (err) {
-      console.log('\n');
-      console.error(colors.red(err.message));
-      console.error(colors.red(err.stack));
+      if (err instanceof Error) {
+        console.log('\n');
+        console.error(colors.red(err.message));
+        if (err.stack) {
+          console.error(colors.red(err.stack));
+        }
+      }
 
       if (argv.debug) {
         console.log(`Current Directory: ${process.cwd()}`);