From cee278fd8aa2fd874a50767d586dfb075260e86a Mon Sep 17 00:00:00 2001
From: Jonathan Goldwasser <jonathan.goldwasser@gmail.com>
Date: Thu, 30 Sep 2021 10:05:41 +0200
Subject: [PATCH] feat(lambda-nodejs): esbuild charset option

Closes #16668
---
 packages/@aws-cdk/aws-lambda-nodejs/README.md |  5 ++-
 .../aws-lambda-nodejs/lib/bundling.ts         |  1 +
 .../@aws-cdk/aws-lambda-nodejs/lib/types.ts   | 38 +++++++++++++++++--
 .../aws-lambda-nodejs/test/bundling.test.ts   |  4 +-
 4 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/packages/@aws-cdk/aws-lambda-nodejs/README.md b/packages/@aws-cdk/aws-lambda-nodejs/README.md
index 22347b28b1dd9..5d80e57b659ca 100644
--- a/packages/@aws-cdk/aws-lambda-nodejs/README.md
+++ b/packages/@aws-cdk/aws-lambda-nodejs/README.md
@@ -186,8 +186,9 @@ new lambda.NodejsFunction(this, 'my-handler', {
     keepNames: true, // defaults to false
     tsconfig: 'custom-tsconfig.json', // use custom-tsconfig.json instead of default,
     metafile: true, // include meta file, defaults to false
-    banner : '/* comments */', // requires esbuild >= 0.9.0, defaults to none
-    footer : '/* comments */', // requires esbuild >= 0.9.0, defaults to none
+    banner: '/* comments */', // requires esbuild >= 0.9.0, defaults to none
+    footer: '/* comments */', // requires esbuild >= 0.9.0, defaults to none
+    charset: Charset.UTF8, // do not escape non-ASCII characters, defaults to Charset.ASCII
   },
 });
 ```
diff --git a/packages/@aws-cdk/aws-lambda-nodejs/lib/bundling.ts b/packages/@aws-cdk/aws-lambda-nodejs/lib/bundling.ts
index 3c33ad74f2471..0d08b70a7be48 100644
--- a/packages/@aws-cdk/aws-lambda-nodejs/lib/bundling.ts
+++ b/packages/@aws-cdk/aws-lambda-nodejs/lib/bundling.ts
@@ -151,6 +151,7 @@ export class Bundling implements cdk.BundlingOptions {
       ...this.props.metafile ? [`--metafile=${pathJoin(options.outputDir, 'index.meta.json')}`] : [],
       ...this.props.banner ? [`--banner:js=${JSON.stringify(this.props.banner)}`] : [],
       ...this.props.footer ? [`--footer:js=${JSON.stringify(this.props.footer)}`] : [],
+      ...this.props.charset ? [`--charset=${this.props.charset}`] : [],
     ];
 
     let depsCommand = '';
diff --git a/packages/@aws-cdk/aws-lambda-nodejs/lib/types.ts b/packages/@aws-cdk/aws-lambda-nodejs/lib/types.ts
index 8d0d263fe64e6..ea3e364dde28b 100644
--- a/packages/@aws-cdk/aws-lambda-nodejs/lib/types.ts
+++ b/packages/@aws-cdk/aws-lambda-nodejs/lib/types.ts
@@ -113,7 +113,7 @@ export interface BundlingOptions {
    * bundle buddy can consume esbuild's metadata format and generates a treemap visualization
    * of the modules in your bundle and how much space each one takes up.
    * @see https://esbuild.github.io/api/#metafile
-   * @default - false
+   * @default false
    */
   readonly metafile?: boolean
 
@@ -124,7 +124,7 @@ export interface BundlingOptions {
    *
    * This is commonly used to insert comments:
    *
-   * @default -  no comments are passed
+   * @default - no comments are passed
    */
   readonly banner? : string
 
@@ -135,10 +135,23 @@ export interface BundlingOptions {
    *
    * This is commonly used to insert comments
    *
-   * @default -  no comments are passed
+   * @default - no comments are passed
    */
   readonly footer? : string
 
+  /**
+   * The charset to use for esbuild's output.
+   *
+   * By default esbuild's output is ASCII-only. Any non-ASCII characters are escaped
+   * using backslash escape sequences. Using escape sequences makes the generated output
+   * slightly bigger, and also makes it harder to read. If you would like for esbuild to print
+   * the original characters without using escape sequences, use `Charset.UTF8`.
+   *
+   * @see https://esbuild.github.io/api/#charset
+   * @default Charset.ASCII
+   */
+  readonly charset?: Charset;
+
   /**
    * Environment variables defined when bundling runs.
    *
@@ -300,3 +313,22 @@ export enum SourceMapMode {
    */
   BOTH = 'both'
 }
+
+/**
+ * Charset for esbuild's output
+ */
+export enum Charset {
+  /**
+   * ASCII
+   *
+   * Any non-ASCII characters are escaped using backslash escape sequences
+   */
+  ASCII = 'ascii',
+
+  /**
+   * UTF-8
+   *
+   * Keep original characters without using escape sequences
+   */
+  UTF8 = 'utf8'
+}
diff --git a/packages/@aws-cdk/aws-lambda-nodejs/test/bundling.test.ts b/packages/@aws-cdk/aws-lambda-nodejs/test/bundling.test.ts
index a38a6fa08d5bc..21c4a7f2343d4 100644
--- a/packages/@aws-cdk/aws-lambda-nodejs/test/bundling.test.ts
+++ b/packages/@aws-cdk/aws-lambda-nodejs/test/bundling.test.ts
@@ -6,7 +6,7 @@ import { AssetHashType, DockerImage } from '@aws-cdk/core';
 import { version as delayVersion } from 'delay/package.json';
 import { Bundling } from '../lib/bundling';
 import { EsbuildInstallation } from '../lib/esbuild-installation';
-import { LogLevel, SourceMapMode } from '../lib/types';
+import { Charset, LogLevel, SourceMapMode } from '../lib/types';
 import * as util from '../lib/util';
 
 jest.mock('@aws-cdk/aws-lambda');
@@ -185,6 +185,7 @@ test('esbuild bundling with esbuild options', () => {
     metafile: true,
     banner: '/* comments */',
     footer: '/* comments */',
+    charset: Charset.UTF8,
     forceDockerBundling: true,
     define: {
       'process.env.KEY': JSON.stringify('VALUE'),
@@ -208,6 +209,7 @@ test('esbuild bundling with esbuild options', () => {
           defineInstructions,
           '--log-level=silent --keep-names --tsconfig=/asset-input/lib/custom-tsconfig.ts',
           '--metafile=/asset-output/index.meta.json --banner:js="/* comments */" --footer:js="/* comments */"',
+          '--charset=utf8',
         ].join(' '),
       ],
     }),