fix: assert compilation errors in OutputPlugin

.changeset/frank-cougars-go.md

@@ -0,0 +1,5 @@
+---
+"@callstack/repack": patch
+---
+
+Handle previous compiler errors and abort bundling in `RepackOutputPlugin`

packages/repack/src/plugins/OutputPlugin/OutputPlugin.ts

@@ -184,6 +184,13 @@ export class OutputPlugin {
     );
 
     compiler.hooks.done.tapPromise('RepackOutputPlugin', async (stats) => {
+      if (stats.hasErrors()) {
+        throw new Error(
+          '[RepackOutputPlugin] Compilation failed:\n' +
+            stats.toString('errors-only')
+        );
+      }
+
       const compilationStats = stats.toJson({
         all: false,
         assets: true,

packages/repack/src/plugins/__tests__/OutputPlugin.test.ts

@@ -1,13 +1,69 @@
+import fs from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
 import {
   type EntryNormalized,
   ModuleFilenameHelpers,
   type StatsChunk,
+  rspack,
 } from '@rspack/core';
+import RspackVirtualModulePlugin from 'rspack-plugin-virtual-module';
 import {
   OutputPlugin,
   type OutputPluginConfig,
 } from '../OutputPlugin/index.js';
 
+async function testCompile(code: string, expectThrow?: string) {
+  // Create a temporary directory to write files to.
+  const tempDir = await fs.mkdtemp(
+    path.join(os.tmpdir(), 'output-plugin-test-')
+  );
+
+  // And then run the compiler with the provided code.
+  try {
+    const compiler = rspack({
+      context: tempDir,
+      mode: 'production',
+      devtool: false,
+      entry: 'index.js',
+      output: {
+        filename: 'index.bundle',
+        path: path.join(tempDir, 'out'),
+      },
+      plugins: [
+        new OutputPlugin({
+          context: tempDir,
+          platform: 'ios',
+          output: {},
+        }),
+        new RspackVirtualModulePlugin({
+          'index.js': code,
+        }),
+      ],
+    });
+
+    const promise = new Promise<void>((resolve, reject) =>
+      compiler.run((error, _stats) => {
+        if (error) {
+          reject(error);
+        } else {
+          resolve();
+        }
+      })
+    );
+
+    // Depending on whether we expect an error or not, assert accordingly.
+    if (expectThrow) {
+      await expect(promise).rejects.toThrow(expectThrow);
+    } else {
+      await expect(promise).resolves.not.toThrow();
+    }
+  } finally {
+    // Delete the temporary directory after the test
+    await fs.rm(tempDir, { recursive: true, force: true });
+  }
+}
+
 const makeChunk = ({
   name,
   entry = false,
@@ -204,4 +260,17 @@ describe('OutputPlugin', () => {
       });
     });
   });
+
+  describe('apply', () => {
+    it('should throw an error when compilation has errors', async () => {
+      await testCompile(
+        'const x = {{{',
+        '[RepackOutputPlugin] Compilation failed:'
+      );
+    });
+
+    it('should complete successfully when compilation succeeds', async () => {
+      await testCompile('const x = {};');
+    });
+  });
 });