fix(lambda-nodejs): parcel is too big to bundle

Stop bundling parcel-bundler and make it an undeclared peer dependency.

Transform build function into a class.

Fixes aws#6340

BREAKING CHANGE: parcel-bundler v1.x is now a peer dependency of @aws-cdk/aws-lambda-nodejs. Please add it to your package.json.

packages/@aws-cdk/aws-lambda-nodejs/README.md

@@ -17,6 +17,15 @@
 
 This library provides constructs for Node.js Lambda functions.
 
+To use this module, you will need to add a dependency on `parcel-bundler` in your
+`package.json`:
+
+```
+yarn add parcel-bundler@^1
+# or
+npm install parcel-bundler@^1
+```
+
 ### Node.js Function
 Define a `NodejsFunction`:
 

packages/@aws-cdk/aws-lambda-nodejs/lib/builder.ts

@@ -0,0 +1,113 @@
+import { spawnSync } from 'child_process';
+import * as fs from 'fs';
+import * as path from 'path';
+import { findPkgPath, updatePkg } from './util';
+
+/**
+ * Builder options
+ */
+export interface BuilderOptions {
+  /**
+   * Entry file
+   */
+  readonly entry: string;
+
+  /**
+   * The output directory
+   */
+  readonly outDir: string;
+
+  /**
+   * Expose modules as UMD under this name
+   */
+  readonly global: string;
+
+  /**
+   * Minify
+   */
+  readonly minify?: boolean;
+
+  /**
+   * Include source maps
+   */
+  readonly sourceMaps?: boolean;
+
+  /**
+   * The cache directory
+   */
+  readonly cacheDir?: string;
+
+  /**
+   * The node version to use as target for Babel
+   */
+  readonly nodeVersion?: string;
+}
+
+/**
+ * Builder
+ */
+export class Builder {
+  private readonly parcelBinPath: string;
+
+  constructor(private readonly options: BuilderOptions) {
+    let parcelPkgPath: string;
+    try {
+      parcelPkgPath = require.resolve('parcel-bundler/package.json'); // This will throw if `parcel-bundler` cannot be found
+    } catch (err) {
+      throw new Error('It looks like parcel-bundler is not installed. Please install v1.x of parcel-bundler with yarn or npm.');
+    }
+    const parcelDir = path.dirname(parcelPkgPath);
+    const parcelPkg = JSON.parse(fs.readFileSync(parcelPkgPath, 'utf8'));
+
+    if (!parcelPkg.version || !/^1\./.test(parcelPkg.version)) { // Peer dependency on parcel v1.x
+      throw new Error(`This module has a peer dependency on parcel-bundler v1.x. Got v${parcelPkg.version}.`);
+    }
+
+    this.parcelBinPath = path.join(parcelDir, parcelPkg.bin.parcel);
+  }
+
+  public build(): void {
+    const pkgPath = findPkgPath();
+    let originalPkg;
+
+    try {
+      if (this.options.nodeVersion && pkgPath) {
+        // Update engines.node (Babel target)
+        originalPkg = updatePkg(pkgPath, {
+          engines: { node: `>= ${this.options.nodeVersion}` }
+        });
+      }
+
+      const args = [
+        'build', this.options.entry,
+        '--out-dir', this.options.outDir,
+        '--out-file', 'index.js',
+        '--global', this.options.global,
+        '--target', 'node',
+        '--bundle-node-modules',
+        '--log-level', '2',
+        !this.options.minify && '--no-minify',
+        !this.options.sourceMaps && '--no-source-maps',
+        ...this.options.cacheDir
+          ? ['--cache-dir', this.options.cacheDir]
+          : [],
+      ].filter(Boolean) as string[];
+
+      const parcel = spawnSync(this.parcelBinPath, args);
+
+      if (parcel.error) {
+        throw parcel.error;
+      }
+
+      if (parcel.status !== 0) {
+        throw new Error(parcel.stdout.toString().trim());
+      }
+    } catch (err) {
+      throw new Error(`Failed to build file at ${this.options.entry}: ${err}`);
+    } finally { // Always restore package.json to original
+      if (pkgPath && originalPkg) {
+        fs.writeFileSync(pkgPath, originalPkg);
+      }
+    }
+  }
+}

packages/@aws-cdk/aws-lambda-nodejs/lib/function.ts

@@ -3,7 +3,7 @@ import * as cdk from '@aws-cdk/core';
 import * as crypto from 'crypto';
 import * as fs from 'fs';
 import * as path from 'path';
-import { build } from './build';
+import { Builder } from './builder';
 import { nodeMajorVersion, parseStackTrace } from './util';
 
 /**
@@ -86,7 +86,7 @@ export class NodejsFunction extends lambda.Function {
     const runtime = props.runtime || defaultRunTime;
 
     // Build with Parcel
-    build({
+    const builder = new Builder({
       entry,
       outDir: handlerDir,
       global: handler,
@@ -95,6 +95,7 @@ export class NodejsFunction extends lambda.Function {
       cacheDir: props.cacheDir,
       nodeVersion: extractVersion(runtime),
     });
+    builder.build();
 
     super(scope, id, {
       ...props,

packages/@aws-cdk/aws-lambda-nodejs/package.json

@@ -88,16 +88,13 @@
     "cdk-build-tools": "1.24.0",
     "cdk-integ-tools": "1.24.0",
     "fs-extra": "^8.1.0",
+    "parcel-bundler": "^1.12.4",
     "pkglint": "1.24.0"
   },
   "dependencies": {
     "@aws-cdk/aws-lambda": "1.24.0",
-    "@aws-cdk/core": "1.24.0",
-    "parcel-bundler": "^1.12.4"
+    "@aws-cdk/core": "1.24.0"
   },
-  "bundledDependencies": [
-    "parcel-bundler"
-  ],
   "homepage": "https://github.com/aws/aws-cdk",
   "peerDependencies": {
     "@aws-cdk/aws-lambda": "1.24.0",
@@ -107,4 +104,4 @@
     "node": ">= 10.3.0"
   },
   "stability": "experimental"
-}
+}

packages/@aws-cdk/aws-lambda-nodejs/test/build.test.ts → packages/@aws-cdk/aws-lambda-nodejs/test/builder.test.ts

@@ -1,5 +1,17 @@
 import { spawnSync } from 'child_process';
-import { build } from '../lib/build';
+import * as fs from 'fs';
+import { Builder } from '../lib/builder';
+
+let parcelPkgPath: string;
+let parcelPkg: Buffer;
+beforeAll(() => {
+  parcelPkgPath = require.resolve('parcel-bundler/package.json');
+  parcelPkg = fs.readFileSync(parcelPkgPath);
+});
+
+afterEach(() => {
+  fs.writeFileSync(parcelPkgPath, parcelPkg);
+});
 
 jest.mock('child_process', () => ({
   spawnSync: jest.fn((_cmd: string, args: string[]) => {
@@ -16,12 +28,13 @@ jest.mock('child_process', () => ({
 }));
 
 test('calls parcel with the correct args', () => {
-  build({
+  const builder = new Builder({
     entry: 'entry',
     global: 'handler',
     outDir: 'out-dir',
     cacheDir: 'cache-dir',
   });
+  builder.build();
 
   expect(spawnSync).toHaveBeenCalledWith(expect.stringContaining('parcel-bundler'), expect.arrayContaining([
     'build', 'entry',
@@ -38,17 +51,31 @@ test('calls parcel with the correct args', () => {
 });
 
 test('throws in case of error', () => {
-  expect(() => build({
+  const builder = new Builder({
     entry: 'error',
     global: 'handler',
     outDir: 'out-dir'
-  })).toThrow('parcel-error');
+  });
+  expect(() => builder.build()).toThrow('parcel-error');
 });
 
 test('throws if status is not 0', () => {
-  expect(() => build({
+  const builder = new Builder({
     entry: 'status',
     global: 'handler',
     outDir: 'out-dir'
-  })).toThrow('status-error');
+  });
+  expect(() => builder.build()).toThrow('status-error');
+});
+
+test('throws when parcel-bundler is not 1.x', () => {
+  fs.writeFileSync(parcelPkgPath, JSON.stringify({
+    ...JSON.parse(parcelPkg.toString()),
+    version: '2.3.4'
+  }));
+  expect(() => new Builder({
+    entry: 'entry',
+    global: 'handler',
+    outDir: 'out-dur'
+  })).toThrow(/This module has a peer dependency on parcel-bundler v1.x. Got v2.3.4./);
 });

packages/@aws-cdk/aws-lambda-nodejs/test/function.test.ts

@@ -4,13 +4,19 @@ import { Stack } from '@aws-cdk/core';
 import * as fs from 'fs-extra';
 import * as path from 'path';
 import { NodejsFunction } from '../lib';
-import { build, BuildOptions } from '../lib/build';
+import { Builder, BuilderOptions } from '../lib/builder';
 
-jest.mock('../lib/build', () => ({
-  build: jest.fn((options: BuildOptions) => {
-    require('fs-extra').ensureDirSync(options.outDir); // eslint-disable-line @typescript-eslint/no-require-imports
-  })
-}));
+jest.mock('../lib/builder', () => {
+  return {
+    Builder: jest.fn().mockImplementation((options: BuilderOptions) => {
+      return {
+        build: jest.fn(() => {
+          require('fs-extra').ensureDirSync(options.outDir); // eslint-disable-line @typescript-eslint/no-require-imports
+        })
+      };
+    })
+  };
+});
 
 let stack: Stack;
 const buildDir = path.join(__dirname, '.build');
@@ -27,7 +33,7 @@ test('NodejsFunction with .ts handler', () => {
   // WHEN
   new NodejsFunction(stack, 'handler1');
 
-  expect(build).toHaveBeenCalledWith(expect.objectContaining({
+  expect(Builder).toHaveBeenCalledWith(expect.objectContaining({
     entry: expect.stringContaining('function.test.handler1.ts'), // Automatically finds .ts handler file
     global: 'handler',
     outDir: expect.stringContaining(buildDir)
@@ -43,7 +49,7 @@ test('NodejsFunction with .js handler', () => {
   new NodejsFunction(stack, 'handler2');
 
   // THEN
-  expect(build).toHaveBeenCalledWith(expect.objectContaining({
+  expect(Builder).toHaveBeenCalledWith(expect.objectContaining({
     entry: expect.stringContaining('function.test.handler2.js'), // Automatically finds .ts handler file
   }));
 });