fix(esbuild): use es2017 target for output bundle

README.md

@@ -6,11 +6,13 @@ Serverless plugin for zero-config JavaScript and TypeScript code bundling using
 ## Features
 
 * Zero-config: Works out of the box without the need to install any other compiler or plugins
-* Supports ES2015 syntax + features (`export`, `import`, `async`, `await`, `Promise`, ...)
+* Supports ESNext syntax with transforming limitations (See *Note*)
 * Supports `sls package`, `sls deploy` and `sls deploy function`
 * Supports `sls invoke local`
 * Integrates nicely with [`serverless-offline`](https://github.com/dherault/serverless-offline)
 
+*Note*: The default JavaScript syntax target is set to [`ES2017`](https://node.green/#ES2017), so the final bundle will be supported by all [AWS Lambda Node.js runtimes](https://docs.aws.amazon.com/lambda/latest/dg/lambda-runtimes.html). If you still using an old lambda runtime and have to respect it you can play with esbuild `target` option, see [JavaScript syntax support](https://github.com/evanw/esbuild#javascript-syntax-support) for more details about syntax transform limitations.
+
 ## Install
 
 ```sh

src/index.ts

@@ -111,6 +111,7 @@ export class EsbuildPlugin implements Plugin {
     const concatUniq = compose(uniq, concat as (l1: BuildOptions[], l2: BuildOptions[]) => BuildOptions[]);
     const withDefaultOptions = mergeWith(concatUniq, {
       bundle: true,
+      target: 'es2017',
       external: ['aws-sdk'],
     });