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Testing PackagerRunner Bundle Processing in Parcel

This test suite validates the PackagerRunner functionality in Parcel, focusing on bundle packaging operations and module integration. It verifies the core bundling process by testing how PackagerRunner handles multiple module assets and configures output paths.

Test Coverage Overview

The test suite provides essential coverage for the PackagerRunner component, focusing on bundle packaging operations.

Key functionality tested includes:

Bundle destination path configuration
Multiple asset integration
Module resolution and packaging
Default Parcel configuration handling

Integration points cover module fixture loading and package configuration integration.

Implementation Analysis

The testing approach implements Jest’s asynchronous testing patterns using async/await syntax for handling bundling operations. The implementation demonstrates clean unit testing practices with proper test isolation.

Technical patterns include:

Fixture-based testing with module resolution
Configuration injection via @parcel/config-default
Async operation validation
Bundle object structure testing

Technical Details

Testing tools and setup:

Jest test framework
Flow type checking
Node.js path module
Assert library for validations
Parcel default configuration package
Custom test fixtures (module-a, module-b)

Best Practices Demonstrated

The test suite exemplifies high-quality testing practices through clear structure and proper isolation. Notable practices include:

Isolated test scope with proper setup
Async/await pattern usage
Fixture-based test data management
Clean configuration handling
Modular test organization

parcel-bundler/parcel

packages/core/core/test/PackagerRunner.test.js

            
// // @flow
// 'use strict';

// const PackagerRunner = require('../src/PackagerRunner');
// const assert = require('assert');
// const path = require('path');

// const config = require('@parcel/config-default');

// describe('PackagerRunner', () => {
//   it('works', async () => {
//     let bundle = {
//       destPath: path.join(__dirname, 'dist', 'bundle.js'),
//       assets: [
//         {blobs: {code: require.resolve('./fixtures/module-a')}},
//         {blobs: {code: require.resolve('./fixtures/module-b')}},
//       ],
//     };

//     let packagerRunner = new PackagerRunner({
//       parcelConfig: config,
//       options: {}
//     });

//     await packagerRunner.runPackager({ bundle });
//   });
// });