fix(lambda): asset metadata invalid for layers (#4205)

* fix(lambda): asset metadata invalid for layers

The `aws:asset:property` metadata entry was "Code" intead of "Content" as it should be for lambda layers.

Fixes #4076
Fixes aws/aws-sam-cli#1411

* fix build

packages/@aws-cdk/aws-lambda/lib/code.ts

@@ -90,7 +90,7 @@ export abstract class Code {
    * class to bind to it. Specifically it's required to allow assets to add
    * metadata for tooling like SAM CLI to be able to find their origins.
    */
-  public bindToResource(_resource: CfnResource) {
+  public bindToResource(_resource: CfnResource, _options?: ResourceBindOptions) {
     return;
   }
 }
@@ -192,16 +192,27 @@ export class AssetCode extends Code {
     };
   }
 
-  public bindToResource(resource: CfnResource) {
+  public bindToResource(resource: CfnResource, options: ResourceBindOptions = { }) {
     if (!this.asset) {
       throw new Error(`bindToResource() must be called after bind()`);
     }
 
-      // https://github.com/aws/aws-cdk/issues/1432
-    this.asset.addResourceMetadata(resource, 'Code');
+    const resourceProperty = options.resourceProperty || 'Code';
+
+    // https://github.com/aws/aws-cdk/issues/1432
+    this.asset.addResourceMetadata(resource, resourceProperty);
   }
 }
 
+export interface ResourceBindOptions {
+  /**
+   * The name of the CloudFormation property to annotate with asset metadata.
+   * @see https://github.com/aws/aws-cdk/issues/1432
+   * @default Code
+   */
+  readonly resourceProperty?: string;
+}
+
 /**
  * Construction properties for {@link CfnParametersCode}.
  */

packages/@aws-cdk/aws-lambda/lib/layers.ts

@@ -192,7 +192,9 @@ export class LayerVersion extends LayerVersionBase {
       licenseInfo: props.license,
     });
 
-    props.code.bindToResource(resource);
+    props.code.bindToResource(resource, {
+      resourceProperty: 'Content'
+    });
 
     this.layerVersionArn = resource.ref;
     this.compatibleRuntimes = props.compatibleRuntimes;

packages/@aws-cdk/aws-lambda/test/test.layers.ts

@@ -1,7 +1,9 @@
-import { expect, haveResource } from '@aws-cdk/assert';
+import { expect, haveResource, ResourcePart } from '@aws-cdk/assert';
 import s3 = require('@aws-cdk/aws-s3');
 import cdk = require('@aws-cdk/core');
+import cxapi = require('@aws-cdk/cx-api');
 import { Test, testCase } from 'nodeunit';
+import path = require('path');
 import lambda = require('../lib');
 
 export = testCase({
@@ -71,4 +73,24 @@ export = testCase({
 
     test.done();
   },
+
+  'asset metadata is added to the cloudformation resource'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    stack.node.setContext(cxapi.ASSET_RESOURCE_METADATA_ENABLED_CONTEXT, true);
+
+    // WHEN
+    new lambda.LayerVersion(stack, 'layer', {
+      code: lambda.Code.fromAsset(path.join(__dirname, 'layer-code'))
+    });
+
+    // THEN
+    expect(stack).to(haveResource('AWS::Lambda::LayerVersion', {
+      Metadata: {
+        'aws:asset:path': 'asset.45f085ecc03a1a22cf003fba3fab28e660c92bcfcd4d0c01b62c7cd191070a2d',
+        'aws:asset:property': 'Content'
+      }
+    }, ResourcePart.CompleteDefinition));
+    test.done();
+  }
 });