Maintenance: Remove undefined From REST API Resolve Method Type Signature #4462
Description
Summary
The way the resolve method works now that we will always return a response:
public async resolve(
event: unknown,
context: Context,
options?: ResolveOptions
): Promise<APIGatewayProxyResult | undefined> {
// ...
const requestContext: RequestContext = {
event,
context,
request,
// this response should be overwritten by the handler, if it isn't
// it means somthing went wrong with the middleware chain
res: new Response('', { status: 500 }),
};
try {
// ...
const middlewareResult = await middleware(
route.params,
requestContext,
() => Promise.resolve()
);
// middleware result takes precedence to allow short-circuiting
const result = middlewareResult ?? requestContext.res;
return handlerResultToProxyResult(result);
} catch (error) {
this.logger.debug(`There was an error processing the request: ${error}`);
const result = await this.handleError(error as Error, {
...requestContext,
scope: options?.scope,
});
return await webResponseToProxyResult(result);
}
} requestContext.res is always initialised at the beginning of the function and we will fallback to that response assuming our middleware doesn't short-circuit.
Why is this needed?
Currently when customers use app.resolve they have to include unnecessary null checks:
export const handler = async (event: APIGatewayProxyEvent, context: Context): Promise<APIGatewayProxyResult> => {
const result = app.resolve(event, context);
console.log(result?.body);
return result ?? someDefault;
};Which area does this relate to?
Event Handler
Solution
No response
Acknowledgment
- This request meets Powertools for AWS Lambda (TypeScript) Tenets
- Should this be considered in other Powertools for AWS Lambda languages? i.e. Python, Java, and .NET
Future readers
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