fix: Throw when config file does not exist (#1156)

Co-authored-by: kongmoumou <kongmoumou@users.noreply.github.com>

packages/wxt/e2e/tests/user-config.test.ts

@@ -157,4 +157,18 @@ describe('User Config', () => {
       await project.fileExists('.output/test-chrome-mv3-development-dev-build'),
     ).toBe(true);
   });
+
+  it('should throw error when config file not exist', async () => {
+    const project = new TestProject();
+    project.addFile(
+      'src/entrypoints/background.ts',
+      `export default defineBackground(
+        () => console.log('Hello background'),
+      );`,
+    );
+
+    await expect(
+      project.build({ configFile: 'foo.config.ts' }),
+    ).rejects.toThrowError(/not found/);
+  });
 });

packages/wxt/src/core/resolve-config.ts

@@ -53,6 +53,9 @@ export async function resolveConfig(
         esmResolve: true,
       },
     });
+    if (inlineConfig.configFile && metadata.layers?.length === 0) {
+      throw Error(`Config file "${inlineConfig.configFile}" not found`);
+    }
     userConfig = loadedConfig ?? {};
     userConfigMetadata = metadata;
   }