fix: cannot have multiple assets in the same scope (backport #1016)

src/code.ts

@@ -10,6 +10,7 @@ import {
 } from './asset';
 import { EntryPoints } from './bundler';
 import { BuildOptions } from './esbuild-types';
+import { uniqueAssetId } from './utils';
 
 function nodeMajorVersion(): number {
   return parseInt(process.versions.node.split('.')[0], 10);
@@ -32,7 +33,7 @@ export class EsbuildCode<
   protected getAsset(scope: Construct): EsbuildAsset<AssetProps> {
     return new EsbuildAsset(
       scope,
-      this.constructor.name,
+      uniqueAssetId(scope, this.constructor.name),
       this.props,
     );
   }
@@ -145,7 +146,7 @@ export class JavaScriptCode extends EsbuildCode<JavaScriptCodeProps> {
   protected getAsset(scope: Construct): EsbuildAsset<AssetProps> {
     return new JSAsset(
       scope,
-      this.constructor.name,
+      uniqueAssetId(scope, this.constructor.name),
       this.props,
     );
   }
@@ -194,7 +195,7 @@ export class TypeScriptCode extends EsbuildCode<TypeScriptCodeProps> {
   protected getAsset(scope: Construct): EsbuildAsset<AssetProps> {
     return new TSAsset(
       scope,
-      this.constructor.name,
+      uniqueAssetId(scope, this.constructor.name),
       this.props,
     );
   }

src/source.ts

@@ -8,6 +8,8 @@ import { Construct } from 'constructs';
 import { AssetBaseProps, AssetProps, JavaScriptAsset, TypeScriptAsset } from './asset';
 import { EntryPoints } from './bundler';
 import { BuildOptions } from './esbuild-types';
+import { uniqueAssetId } from './utils';
+
 
 export interface JavaScriptSourceProps extends AssetBaseProps{};
 export interface TypeScriptSourceProps extends AssetBaseProps{};
@@ -75,7 +77,7 @@ abstract class Source<
     if (!this.asset) {
       this.asset = new this.assetClass(
         scope,
-        this.constructor.name,
+        uniqueAssetId(scope, this.constructor.name),
         this.props,
       );
     } else if (Stack.of(this.asset) !== Stack.of(scope)) {

src/utils.ts

@@ -1,7 +1,23 @@
+import { IConstruct } from 'constructs';
+
 export function isEsbuildError(error: unknown): boolean {
   return !!error
   && typeof error == 'object'
   && error != null
   && 'errors' in error
   && 'warnings' in error;
 }
+
+
+const assetIds = new WeakMap<IConstruct, number>();
+export const uniqueAssetId = (scope: IConstruct, name: string) => {
+  const nextId = (assetIds.get(scope) ?? 0) + 1;
+  assetIds.set(scope, nextId);
+
+  // Only one asset per scope, skip the id
+  if (nextId === 1) {
+    return name;
+  }
+
+  return `${name}${nextId}`;
+};

test/code.test.ts

@@ -342,3 +342,21 @@ describe('Amazon CloudWatch Synthetics', () => {
     });
   });
 });
+
+
+describe('multiple Code in the same scope', () => {
+  it('does not throw', () => {
+    const stack = new Stack();
+
+    const codeOne = new TypeScriptCode('fixtures/handlers/ts-handler.ts', {
+      buildOptions: { absWorkingDir: resolve(__dirname) },
+    });
+
+    const codeTwo = new TypeScriptCode('fixtures/handlers/ts-handler.ts', {
+      buildOptions: { absWorkingDir: resolve(__dirname) },
+    });
+
+    codeOne.bind(stack);
+    codeTwo.bind(stack);
+  });
+});

test/source.test.ts

@@ -178,4 +178,36 @@ describe('source', () => {
       expect(source.props.buildOptions.platform).toBe('browser');
     });
   });
+
+  describe('with multiple sources in the same scope', () => {
+    it('does not throw', () => {
+      const stack = new Stack();
+
+      const sourceOne = new TypeScriptSource('fixtures/handlers/ts-handler.ts', {
+        buildOptions: {
+          absWorkingDir: resolve(__dirname),
+        },
+      });
+      const sourceTwo = new TypeScriptSource('fixtures/handlers/ts-handler.ts', {
+        buildOptions: {
+          absWorkingDir: resolve(__dirname),
+        },
+      });
+
+      const destinationBucket = new Bucket(stack, 'WebsiteBucket', {
+        autoDeleteObjects: true,
+        publicReadAccess: true,
+        removalPolicy: RemovalPolicy.DESTROY,
+        websiteIndexDocument: 'index.html',
+      });
+
+      new BucketDeployment(stack, 'MultipleAssets', {
+        destinationBucket,
+        sources: [
+          sourceOne,
+          sourceTwo,
+        ],
+      });
+    });
+  });
 });