Auto lint and build examples

Author: flochaz

Diff for: CONTRIBUTING.md

@@ -147,6 +147,30 @@ You can run the end-to-end tests automatically on your forked project by followi
 4. In the run-e2e-tests workflow page, select "Run workflow" and run it on the desired branch.
 
 > :warning: **Don't automatically run end-to-end tests on branch push or PRs**. A malicious attacker can submit a pull request to attack your AWS account. Ideally, use a blank account without any important workload/data, and limit `AWS_ROLE_ARN_TO_ASSUME` permission to least minimum privilege.
+
+
+### Examples
+
+As part of the repo you will find an examples folder at the root. This folder contains examples (written with CDK for now) of deployable AWS Lambda functions using Powertools.
+
+To test your updates with these examples you just have to:
+
+1. Build your local version of *aws-lambda-powertools-typescript* npm packages with `npm run lerna-package`
+1. Update their references in examples
+    ```
+    cd examples/cdk
+    npm install ../../packages/**/dist/aws-lambda-powertools-*
+    ```
+1. Run cdk tests
+    ```
+    npm run test
+    ```
+1. Deploy
+    ```
+    npm run cdk deploy
+    ```
+
+Previous command will deploy AWS resources therefore you will need an AWS account and it might incur in some costs which should be covered by the [AWS Free Tier](https://aws.amazon.com/free/?all-free-tier.sort-by=item.additionalFields.SortRank&all-free-tier.sort-order=asc&awsf.Free%20Tier%20Types=*all&awsf.Free%20Tier%20Categories=*all). If you don't have an AWS Account follow [these instructions to create one](https://aws.amazon.com/premiumsupport/knowledge-center/create-and-activate-aws-account/).
 ### Conventions
 
 Category | Convention

Diff for: examples/cdk/bin/cdk-app.ts

@@ -1,7 +1,7 @@
 #!/usr/bin/env node
 import 'source-map-support/register';
 import * as cdk from 'aws-cdk-lib';
-import { CdkAppStack } from '../lib/example-stack';
+import { CdkAppStack } from '../src/example-stack';
 
 const app = new cdk.App();
 new CdkAppStack(app, 'CdkAppStack', {});

Diff for: examples/cdk/jest.config.js

@@ -1,6 +1,6 @@
 module.exports = {
   testEnvironment: 'node',
-  roots: ['<rootDir>/test'],
+  roots: ['<rootDir>/tests'],
   testMatch: ['**/*.test.ts'],
   transform: {
     '^.+\\.tsx?$': 'ts-jest'

Diff for: examples/cdk/package-lock.json

@@ -1,13 +1,13 @@
 {
   "name": "cdk-app",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "bin": {
     "cdk-app": "bin/cdk-app.js"
   },
   "scripts": {
     "build": "tsc --skipLibCheck",
     "watch": "tsc -w",
-    "test": "jest",
+    "test": "npm run build && jest",
     "cdk": "cdk"
   },
   "devDependencies": {

Diff for: examples/cdk/package.json

@@ -12,7 +12,7 @@ const metrics = new Metrics({ namespace: namespace, serviceName: serviceName });
 const logger = new Logger({ logLevel: 'INFO', serviceName: serviceName });
 const tracer = new Tracer({ serviceName: serviceName });
 
-const lambdaHandler = async (event: typeof Events.Custom.CustomEvent, context: Context) => {
+const lambdaHandler = async (event: typeof Events.Custom.CustomEvent, context: Context): Promise<unknown> => {
   // ### Experiment with Logger
   // AWS Lambda context is automatically injected by the middleware
 
@@ -32,7 +32,7 @@ const lambdaHandler = async (event: typeof Events.Custom.CustomEvent, context: C
   const metricWithItsOwnDimensions = metrics.singleMetric();
   metricWithItsOwnDimensions.addDimension('InnerDimension', 'true');
   metricWithItsOwnDimensions.addMetric('single-metric', MetricUnits.Percent, 50);
-  
+
   // ### Experiment with Tracer
 
   // Service & Cold Start annotations will be added for you by the decorator/middleware
@@ -58,16 +58,18 @@ const lambdaHandler = async (event: typeof Events.Custom.CustomEvent, context: C
     tracer.setSegment(handlerSegment);
     // The main segment (facade) will be closed for you at the end by the decorator/middleware
   }
-  
+
   return res;
-}
+};
 
 // We instrument the handler with the various Middy middlewares
 export const handler = middy(lambdaHandler)
   .use(captureLambdaHandler(tracer))
-  .use(logMetrics(metrics, {
-    captureColdStartMetric: true,
-    throwOnEmptyMetrics: true,
-    defaultDimensions: { environment: 'example', type: 'withDecorator' },
-  }))
-  .use(injectLambdaContext(logger));
+  .use(
+    logMetrics(metrics, {
+      captureColdStartMetric: true,
+      throwOnEmptyMetrics: true,
+      defaultDimensions: { environment: 'example', type: 'withDecorator' },
+    })
+  )
+  .use(injectLambdaContext(logger));

Diff for: examples/cdk/lib/example-function.MyFunction.ts renamed to examples/cdk/src/example-function.MyFunction.ts

@@ -7,19 +7,19 @@ import { captureLambdaHandler, Tracer } from '@aws-lambda-powertools/tracer';
 const tracer = new Tracer({ serviceName: 'tracerDisabledFn', enabled: false });
 
 // In this example we are using the middleware pattern but the same applies also the captureLambdaHandler decorator or to manual instrumentation
-const lambdaHandler = async (event: typeof Events.Custom.CustomEvent, context: Context) => {
+const lambdaHandler = async (event: typeof Events.Custom.CustomEvent, context: Context): Promise<unknown> => {
   // No tracing will be done and the commands will be ignored, this is useful for testing
   tracer.putAnnotation('awsRequestId', context.awsRequestId);
   tracer.putMetadata('eventPayload', event);
-  
+
   let res;
   try {
     res = { foo: 'bar' };
   } catch (err) {
     throw err;
   }
-  
+
   return res;
-}
+};
 
-export const handler = middy(lambdaHandler).use(captureLambdaHandler(tracer));
+export const handler = middy(lambdaHandler).use(captureLambdaHandler(tracer));

Diff for: examples/cdk/lib/example-function.MyFunctionWithDecorator.ts renamed to examples/cdk/src/example-function.MyFunctionWithDecorator.ts

@@ -7,24 +7,24 @@ const tracer = new Tracer({ serviceName: 'tracerMiddlewareFn' });
 // Alternatively, you can also set the service name using the POWERTOOLS_SERVICE_NAME environment variable
 // Learn more at: https://docs.aws.amazon.com/lambda/latest/dg/configuration-envvars.html
 
-const lambdaHandler = async (event: typeof Events.Custom.CustomEvent, context: Context) => {
+const lambdaHandler = async (event: typeof Events.Custom.CustomEvent, context: Context): Promise<unknown> => {
   // Add custom annotation & metadata
   tracer.putAnnotation('awsRequestId', context.awsRequestId);
   tracer.putMetadata('eventPayload', event);
-  
+
   let res;
   try {
     res = { foo: 'bar' };
   } catch (err) {
     throw err;
   }
-  
+
   return res;
-}
+};
 
 // We instrument the handler with the Middy middleware and the Tracer will automatically:
 // * handle the lifecycle of the subsegment
 // * create a ColdStart annotation to easily filter traces that have had an initialization overhead
 // * create a Service annotation to easily filter traces that have a specific service name
 // * captures any response, or full exceptions generated by the handler, and include them as tracing metadata
-export const handler = middy(lambdaHandler).use(captureLambdaHandler(tracer));
+export const handler = middy(lambdaHandler).use(captureLambdaHandler(tracer));

Diff for: examples/cdk/lib/example-function.MyFunctionWithMiddy.ts renamed to examples/cdk/src/example-function.MyFunctionWithMiddy.ts

@@ -12,7 +12,6 @@ interface ExampleFunctionProps {
 }
 
 class ExampleFunction extends Construct {
-  public function: NodejsFunction;
 
   public constructor(scope: Construct, id: string, props: ExampleFunctionProps) {
     super(scope, id);
@@ -32,7 +31,7 @@ class ExampleFunction extends Construct {
         onUpdate: {
           service: 'Lambda',
           action: 'invoke',
-          physicalResourceId: custom_resources.PhysicalResourceId.of(new Date().toISOString()),
+          physicalResourceId: custom_resources.PhysicalResourceId.of(`${functionName}-${i}`),
           parameters: {
             FunctionName: fn.functionName,
             InvocationType: 'RequestResponse',