feat: use stringified tokens for resource attributes instead of strong types (#712)

This change removes all strong-types generated to represent 
CloudFormation resource attributes that return a string  (such 
as `QueueArn`, `DeploymentGroupId`) and replaces them 
with `string` that contains a stringified token (via #518).

This allows working with these attributes as if they were regular
strings, and dramatically simplifies the type-system and unneeded
wrapping when assigning values to such attributes.

The ".ref" property of each resource has been replaced with
a property named according to the actual semantic meaning
of the intrinsic reference (such as `queueArn`), and 
also returns a `string`.

Users can test if a string contains stringified tokens using the function 
`unresolved(o)`, which can be applied to either strings or objects 
(previously was `isToken(o)`).

Fixes #695 (opened #744 to follow up on non-string attributes)

Author: Elad Ben-Israel

build.sh

@@ -5,6 +5,11 @@ if [ ! -d node_modules ]; then
     /bin/bash ./install.sh
 fi
 
+fail() {
+  echo "❌  Last command failed. Scroll up to see errors in log."
+  exit 1
+}
+
 /bin/bash ./git-secrets-scan.sh
 
 BUILD_INDICATOR=".BUILD_COMPLETED"
@@ -19,10 +24,10 @@ trap "rm -rf $MERKLE_BUILD_CACHE" EXIT
 
 echo "============================================================================================="
 echo "building..."
-time lerna exec --stream "npm run build"
+time lerna run --no-bail --stream build || fail
 
 echo "============================================================================================="
 echo "testing..."
-lerna run --stream test
+lerna run --no-bail --stream test || fail
 
 touch $BUILD_INDICATOR

docs/src/examples.rst

@@ -168,8 +168,8 @@ The following example creates the Aurora database **MyAuroraDatabase**.
        new rds.DatabaseCluster(this, 'MyRdsDb', {
          defaultDatabaseName: 'MyAuroraDatabase',
          masterUser: {
-           username: new cdk.Token('admin'),
-           password: new cdk.Token('123456')
+           username: 'admin',
+           password: '123456'
          },
          engine: rds.DatabaseClusterEngine.Aurora,
          instanceProps: {

examples/cdk-examples-typescript/chat-app/index.ts

@@ -13,7 +13,7 @@ class MyStack extends cdk.Stack {
         new CognitoChatRoomPool(this, 'UserPool');
 
         const bucket = s3.BucketRef.import(this, 'DougsBucket', {
-            bucketName: new s3.BucketName('dougs-chat-app')
+            bucketName: 'dougs-chat-app'
         });
 
         new ChatAppFunction(this, 'StartAddBucket', {

packages/@aws-cdk/aws-cloudformation/examples/index.ts renamed to examples/cdk-examples-typescript/custom-resource/index.ts

@@ -1,8 +1,8 @@
+import { CustomResource } from '@aws-cdk/aws-cloudformation';
 import lambda = require('@aws-cdk/aws-lambda');
 import { cloudformation as s3 } from '@aws-cdk/aws-s3';
 import cdk = require('@aws-cdk/cdk');
 import fs = require('fs');
-import { CustomResource, SingletonLambda } from '../lib';
 
 interface DemoResourceProps {
     /**
@@ -18,24 +18,24 @@ interface DemoResourceProps {
 
 class DemoResource extends cdk.Construct implements cdk.IDependable {
     public readonly dependencyElements: cdk.IDependable[];
-    public readonly response: cdk.Token;
+    public readonly response: string;
 
     constructor(parent: cdk.Construct, name: string, props: DemoResourceProps) {
         super(parent, name);
 
         const resource = new CustomResource(this, 'Resource', {
-            lambdaProvider: new SingletonLambda(this, 'Singleton', {
+            lambdaProvider: new lambda.SingletonFunction(this, 'Singleton', {
                 uuid: 'f7d4f730-4ee1-11e8-9c2d-fa7ae01bbebc',
                 // This makes the demo only work as top-level TypeScript program, but that's fine for now
-                code: new lambda.LambdaInlineCode(fs.readFileSync('integ.trivial-lambda-provider.py', { encoding: 'utf-8' })),
+                code: lambda.Code.inline(fs.readFileSync('provider.py', { encoding: 'utf-8' })),
                 handler: 'index.main',
                 timeout: 300,
-                runtime: lambda.LambdaRuntime.Python27,
+                runtime: lambda.Runtime.Python27,
             }),
             properties: props
         });
 
-        this.response = resource.getAtt('Response');
+        this.response = resource.getAtt('Response').toString();
         this.dependencyElements = [resource];
     }
 }
@@ -101,4 +101,4 @@ new SucceedingStack(app, 'SucceedingStack');
 new FailCreationStack(app, 'FailCreationStack');
 new FailAfterCreatingStack(app, 'FailAfterCreatingStack');
 
-process.stdout.write(app.run());
+process.stdout.write(app.run());

packages/@aws-cdk/aws-cloudformation/examples/provider.py renamed to examples/cdk-examples-typescript/custom-resource/provider.py

@@ -23,4 +23,4 @@ def main(event, context):
     except Exception as e:
         log.exception(e)
         # cfnresponse's error message is always "see CloudWatch"
-        cfnresponse.send(event, context, cfnresponse.FAILED, {}, physical_id)
+        cfnresponse.send(event, context, cfnresponse.FAILED, {}, physical_id)

examples/cdk-examples-typescript/neptune-demo/index.ts

@@ -1,6 +1,5 @@
 import ec2 = require('@aws-cdk/aws-ec2');
 import neptune = require('@aws-cdk/aws-neptune');
-import rds = require('@aws-cdk/aws-rds');
 import cdk = require('@aws-cdk/cdk');
 
 class NeptuneDemoStack extends cdk.Stack {
@@ -19,8 +18,8 @@ class NeptuneDemoStack extends cdk.Stack {
             masterUser: {
                 // This would normally be imported from SSM parmeter store encrypted string,
                 // but don't want to overcomplicate the example
-                username: new rds.Username('admin'),
-                password: new rds.Password('eRSDwst7lpzu'),
+                username: 'admin',
+                password: 'eRSDwst7lpzu',
             }
         });
         database.connections.allowDefaultPortFrom(new ec2.AnyIPv4(), 'Allow the world to connect');

packages/@aws-cdk/assets/lib/asset.ts

@@ -47,18 +47,18 @@ export class Asset extends cdk.Construct {
     /**
      * Attribute that represents the name of the bucket this asset exists in.
      */
-    public readonly s3BucketName: s3.BucketName;
+    public readonly s3BucketName: string;
 
     /**
      * Attribute which represents the S3 object key of this asset.
      */
-    public readonly s3ObjectKey: s3.ObjectKey;
+    public readonly s3ObjectKey: string;
 
     /**
      * Attribute which represents the S3 URL of this asset.
      * @example https://s3.us-west-1.amazonaws.com/bucket/key
      */
-    public readonly s3Url: s3.S3Url;
+    public readonly s3Url: string;
 
     /**
      * Resolved full-path location of this asset.
@@ -70,7 +70,7 @@ export class Asset extends cdk.Construct {
     /**
      * The S3 prefix where all different versions of this asset are stored
      */
-    private readonly s3Prefix: cdk.Token;
+    private readonly s3Prefix: string;
 
     constructor(parent: cdk.Construct, id: string, props: GenericAssetProps) {
         super(parent, id);
@@ -94,10 +94,10 @@ export class Asset extends cdk.Construct {
             description: `S3 key for asset version "${this.path}"`
         });
 
-        this.s3BucketName = new s3.BucketName(bucketParam.value);
-        this.s3Prefix = new cdk.FnSelect(0, new cdk.FnSplit(cxapi.ASSET_PREFIX_SEPARATOR, keyParam.value));
-        const s3Filename = new cdk.FnSelect(1, new cdk.FnSplit(cxapi.ASSET_PREFIX_SEPARATOR, keyParam.value));
-        this.s3ObjectKey = new s3.ObjectKey(new cdk.FnConcat(this.s3Prefix, s3Filename));
+        this.s3BucketName = bucketParam.value.toString();
+        this.s3Prefix = new cdk.FnSelect(0, new cdk.FnSplit(cxapi.ASSET_PREFIX_SEPARATOR, keyParam.value)).toString();
+        const s3Filename = new cdk.FnSelect(1, new cdk.FnSplit(cxapi.ASSET_PREFIX_SEPARATOR, keyParam.value)).toString();
+        this.s3ObjectKey = `${this.s3Prefix}${s3Filename}`;
 
         this.bucket = s3.BucketRef.import(this, 'AssetBucket', {
             bucketName: this.s3BucketName

packages/@aws-cdk/aws-apigateway/lib/deployment.ts

@@ -1,6 +1,6 @@
 import cdk = require('@aws-cdk/cdk');
 import crypto = require('crypto');
-import { cloudformation, DeploymentId } from './apigateway.generated';
+import { cloudformation } from './apigateway.generated';
 import { RestApiRef } from './restapi-ref';
 
 export interface DeploymentProps  {
@@ -55,7 +55,7 @@ export interface DeploymentProps  {
  * automatically for the `restApi.latestDeployment` deployment.
  */
 export class Deployment extends cdk.Construct implements cdk.IDependable {
-    public readonly deploymentId: DeploymentId;
+    public readonly deploymentId: string;
     public readonly api: RestApiRef;
 
     /**
@@ -78,7 +78,7 @@ export class Deployment extends cdk.Construct implements cdk.IDependable {
         }
 
         this.api = props.api;
-        this.deploymentId = new DeploymentId(() => this.resource.ref);
+        this.deploymentId = new cdk.Token(() => this.resource.deploymentId).toString();
         this.dependencyElements.push(this.resource);
     }
 
@@ -142,13 +142,13 @@ class LatestDeploymentResource extends cloudformation.DeploymentResource {
      * Returns a lazy reference to this resource (evaluated only upon synthesis).
      */
     public get ref() {
-        return new DeploymentId(() => ({ Ref: this.lazyLogicalId }));
+        return new cdk.Token(() => ({ Ref: this.lazyLogicalId })).toString();
     }
 
     /**
      * Does nothing.
      */
-    public set ref(_v: DeploymentId) {
+    public set ref(_v: string) {
         return;
     }
 

packages/@aws-cdk/aws-apigateway/lib/integrations/aws.ts

@@ -68,7 +68,7 @@ export class AwsIntegration extends Integration {
         super({
             type,
             integrationHttpMethod: 'POST',
-            uri: cdk.Arn.fromComponents({
+            uri: cdk.ArnUtils.fromComponents({
                 service: 'apigateway',
                 account: backend,
                 resource: apiType,

packages/@aws-cdk/aws-apigateway/lib/method.ts

@@ -1,5 +1,5 @@
 import cdk = require('@aws-cdk/cdk');
-import { AuthorizerId, cloudformation, MethodId } from './apigateway.generated';
+import { cloudformation } from './apigateway.generated';
 import { Integration } from './integration';
 import { MockIntegration } from './integrations/mock';
 import { IRestApiResource } from './resource';
@@ -26,7 +26,7 @@ export interface MethodOptions {
      * NOTE: in the future this will be replaced with an `AuthorizerRef`
      * construct.
      */
-    authorizerId?: AuthorizerId;
+    authorizerId?: string;
 
     /**
      * Indicates whether the method requires clients to submit a valid API key.
@@ -65,7 +65,7 @@ export interface MethodProps {
 }
 
 export class Method extends cdk.Construct {
-    public readonly methodId: MethodId;
+    public readonly methodId: string;
     public readonly httpMethod: string;
     public readonly resource: IRestApiResource;
     public readonly restApi: RestApi;
@@ -115,7 +115,7 @@ export class Method extends cdk.Construct {
      * NOTE: {stage} will refer to the `restApi.deploymentStage`, which will
      * automatically set if auto-deploy is enabled.
      */
-    public get methodArn(): cdk.Arn {
+    public get methodArn(): string {
         if (!this.restApi.deploymentStage) {
             throw new Error('There is no stage associated with this restApi. Either use `autoDeploy` or explicitly assign `deploymentStage`');
         }
@@ -128,7 +128,7 @@ export class Method extends cdk.Construct {
      * Returns an execute-api ARN for this method's "test-invoke-stage" stage.
      * This stage is used by the AWS Console UI when testing the method.
      */
-    public get testMethodArn(): cdk.Arn {
+    public get testMethodArn(): string {
         return this.restApi.executeApiArn(this.httpMethod, this.resource.resourcePath, 'test-invoke-stage');
     }
 
@@ -156,7 +156,7 @@ export class Method extends cdk.Construct {
             credentials = options.credentialsRole.roleArn;
         } else if (options.credentialsPassthrough) {
             // arn:aws:iam::*:user/*
-            credentials = cdk.Arn.fromComponents({ service: 'iam', region: '', account: '*', resource: 'user', sep: '/', resourceName: '*' });
+            credentials = cdk.ArnUtils.fromComponents({ service: 'iam', region: '', account: '*', resource: 'user', sep: '/', resourceName: '*' });
         }
 
         return {