fix: esbuildBinaryPath not working with Code, not available for InlineCode

src/asset.ts

@@ -61,9 +61,7 @@ export class EsbuildAsset<Props extends AssetProps> extends S3Asset {
   ) {
     const {
       assetHash,
-      copyDir,
       buildOptions: options = {},
-      buildFn,
     } = props;
     const entryPoints: string[] | Record<string, string> =
       typeof props.entryPoints === 'string' ? [props.entryPoints] : props.entryPoints;
@@ -110,9 +108,8 @@ export class EsbuildAsset<Props extends AssetProps> extends S3Asset {
       bundling: new EsbuildBundler(
         relativeEntryPoints,
         {
+          ...props,
           buildOptions,
-          copyDir,
-          buildFn,
         },
       ),
     });

src/bundler.ts

@@ -7,7 +7,7 @@ import {
   ILocalBundling,
 } from 'aws-cdk-lib';
 import { BuildFailure, BuildOptions, BuildResult } from './esbuild-types';
-import { buildSync } from './esbuild-wrapper';
+import { buildSync, wrapWithEsbuildBinaryPath } from './esbuild-wrapper';
 import { printBuildMessages } from './formatMessages';
 
 /**
@@ -152,9 +152,6 @@ export class EsbuildBundler {
     if (props?.buildOptions?.outfile && props?.buildOptions?.outdir) {
       throw new Error('Cannot use both "outfile" and "outdir"');
     }
-
-    const { buildFn = buildSync } = this.props;
-
     this.local = {
       tryBundle: (outputDir: string, _options: BundlingOptions): boolean => {
 
@@ -178,13 +175,9 @@ export class EsbuildBundler {
           });
         }
 
-        const originalEsbuildBinaryPath = process.env.ESBUILD_BINARY_PATH;
-        if (this.props.esbuildBinaryPath) {
-          process.env.ESBUILD_BINARY_PATH = this.props.esbuildBinaryPath;
-        }
-
         try {
-          const buildResult: BuildResult = buildFn({
+          const { buildFn = buildSync } = this.props;
+          const buildResult: BuildResult = wrapWithEsbuildBinaryPath(buildFn, this.props.esbuildBinaryPath)({
             entryPoints,
             ...(this.props?.buildOptions || {}),
             ...this.getOutputOptions(outputDir, { normalize, join }),
@@ -195,14 +188,6 @@ export class EsbuildBundler {
           printBuildMessages(error as BuildFailure, { prefix: 'Build ' });
         }
 
-        /**
-         * only reset `ESBUILD_BINARY_PATH` if it was explicitly set via the construct props
-         * since `esbuild` itself sometimes sets it (eg. when running in yarn 2 plug&play)
-         */
-        if (this.props.esbuildBinaryPath) {
-          process.env.ESBUILD_BINARY_PATH = originalEsbuildBinaryPath;
-        }
-
         return true;
       },
     };

src/esbuild-wrapper.ts

@@ -8,3 +8,28 @@ function esbuild() {
 export const buildSync = esbuild().buildSync;
 export const formatMessagesSync = esbuild().formatMessagesSync;
 export const transformSync = esbuild().transformSync;
+
+export function wrapWithEsbuildBinaryPath<T extends CallableFunction>(fn: T, esbuildBinaryPath?: string) {
+  if (!esbuildBinaryPath) {
+    return fn;
+  }
+
+  return (...args: unknown[]) => {
+    const originalEsbuildBinaryPath = process.env.ESBUILD_BINARY_PATH;
+    if (esbuildBinaryPath) {
+      process.env.ESBUILD_BINARY_PATH = esbuildBinaryPath;
+    }
+
+    const result = fn(...args);
+
+    /**
+     * only reset `ESBUILD_BINARY_PATH` if it was explicitly set via the construct props
+     * since `esbuild` itself sometimes sets it (eg. when running in yarn 2 plug&play)
+     */
+    if (esbuildBinaryPath) {
+      process.env.ESBUILD_BINARY_PATH = originalEsbuildBinaryPath;
+    }
+
+    return result;
+  };
+}

src/inline-code.ts

@@ -1,6 +1,6 @@
 import { InlineCode } from 'aws-cdk-lib/aws-lambda';
 import { TransformOptions, Loader, TransformFailure } from './esbuild-types';
-import { transformSync } from './esbuild-wrapper';
+import { transformSync, wrapWithEsbuildBinaryPath } from './esbuild-wrapper';
 import { printBuildMessages } from './formatMessages';
 
 /**
@@ -27,6 +27,15 @@ export interface TransformerProps {
    * @default esbuild.transformSync
    */
   readonly transformFn?: any;
+
+  /**
+   * Path to the binary used by esbuild.
+   *
+   * This is the same as setting the ESBUILD_BINARY_PATH environment variable.
+   *
+   * @stability experimental
+   */
+  readonly esbuildBinaryPath?: string;
 }
 
 abstract class BaseInlineCode extends InlineCode {
@@ -35,10 +44,14 @@ abstract class BaseInlineCode extends InlineCode {
     props: TransformerProps,
   ) {
 
-    const { transformFn = transformSync, transformOptions = {} } = props;
+    const {
+      transformFn = transformSync,
+      transformOptions = {},
+      esbuildBinaryPath,
+    } = props;
 
     try {
-      const transformedCode = transformFn(code, {
+      const transformedCode = wrapWithEsbuildBinaryPath(transformFn, esbuildBinaryPath)(code, {
         ...transformOptions,
       });
       printBuildMessages(transformedCode, { prefix: 'Transform ' });
@@ -53,7 +66,15 @@ abstract class BaseInlineCode extends InlineCode {
 }
 
 function instanceOfTransformerProps(object: any): object is TransformerProps {
-  return 'transformOptions' in object || 'transformFn' in object;
+  return [
+    'transformOptions',
+    'transformFn',
+    'esbuildBinaryPath',
+  ].reduce(
+    (isTransformerProps: boolean, propToCheck: string): boolean =>
+      (isTransformerProps || (propToCheck in object)),
+    false,
+  );
 }
 
 function transformerProps(loader: Loader, props?: TransformerProps | TransformOptions): TransformerProps {

test/code.test.ts

@@ -8,6 +8,7 @@ import { Stack } from 'aws-cdk-lib';
 import { Function, Runtime as LambdaRuntime } from 'aws-cdk-lib/aws-lambda';
 import { mocked } from 'jest-mock';
 import { JavaScriptCode, TypeScriptCode } from '../src/code';
+import { BuildOptions } from '../src/esbuild-types';
 import { buildSync } from '../src/esbuild-wrapper';
 
 describe('code', () => {
@@ -145,6 +146,36 @@ describe('code', () => {
   });
 });
 
+
+describe('given a custom esbuildBinaryPath', () => {
+  it('should set the ESBUILD_BINARY_PATH env variable', () => {
+    const mockLogger = jest.fn();
+    const customBuild = (options: BuildOptions) => {
+      mockLogger(process.env.ESBUILD_BINARY_PATH);
+      return buildSync(options);
+    };
+
+    expect(() => {
+      const stack = new Stack();
+
+      const code = new TypeScriptCode('fixtures/handlers/ts-handler.ts', {
+        buildOptions: { absWorkingDir: resolve(__dirname) },
+        buildFn: customBuild,
+        esbuildBinaryPath: 'dummy-binary',
+      });
+
+      new Function(stack, 'MyFunction', {
+        runtime: LambdaRuntime.NODEJS_14_X,
+        handler: 'index.handler',
+        code,
+      });
+    }).not.toThrow();
+
+    expect(mockLogger).toHaveBeenCalledTimes(1);
+    expect(mockLogger).toHaveBeenCalledWith('dummy-binary');
+  });
+});
+
 describe('AWS Lambda', () => {
   describe('TypeScriptCode can be used in Lambda Function', () => {
     it('should not throw', () => {

test/inline-code.test.ts

@@ -134,4 +134,26 @@ describe('using transformerProps', () => {
       );
     });
   });
+
+  describe('given a custom esbuildBinaryPath', () => {
+    it('should set the ESBUILD_BINARY_PATH env variable', () => {
+      const mockLogger = jest.fn();
+      const customTransform = () => {
+        mockLogger(process.env.ESBUILD_BINARY_PATH);
+        return {
+          code: 'console.log("test");',
+          map: '',
+          warnings: [],
+        };
+      };
+
+      new InlineTypeScriptCode('let x: number = 1', {
+        transformFn: customTransform,
+        esbuildBinaryPath: 'dummy-binary',
+      });
+
+      expect(mockLogger).toHaveBeenCalledTimes(1);
+      expect(mockLogger).toHaveBeenCalledWith('dummy-binary');
+    });
+  });
 });