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

Fixes #993

src/source.ts

@@ -4,12 +4,25 @@ import {
   ISource,
   SourceConfig,
 } from 'aws-cdk-lib/aws-s3-deployment';
-import { Construct } from 'constructs';
+import { Construct, IConstruct } from 'constructs';
 import { TypeScriptAsset, TypeScriptAssetProps } from './asset';
 import { EntryPoints } from './bundler';
 import { TypeScriptCodeProps } from './code';
 import { BuildOptions } from './esbuild-types';
 
+const assetIds = new WeakMap<IConstruct, number>();
+const assetId = (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}`;
+};
+
 export interface TypeScriptSourceProps extends TypeScriptCodeProps {};
 
 export class TypeScriptSource implements ISource {
@@ -66,7 +79,7 @@ export class TypeScriptSource implements ISource {
     if (!this.asset) {
       this.asset = new TypeScriptAsset(
         scope,
-        this.constructor.name,
+        assetId(scope, this.constructor.name),
         this.props,
       );
     } else if (Stack.of(this.asset) !== Stack.of(scope)) {

test/source.test.ts

@@ -176,4 +176,36 @@ 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,
+        ],
+      });
+    });
+  });
 });