feat(type-safe-api): coerce request parameters into defined types for…

… typescript (#551)

Previously request parameters were always strings no matter the type defined in the model. Now we
add code to the typescript lambda handler wrappers to convert to appropriate types. Supports the
Smithy supported request parameters number/string/bool/date and arrays of those. Responds with a 400
error if the wrong type is passed, and includes headers from any response header interceptors in
this validation response.

BREAKING CHANGE: Removed RequestArrayParameters from input and type signature of
handlers/interceptors. number/bool/date request parameters will be coerced to their type defined in
the model. useIntegerType: true is specified by default for smithy to openapi conversion as this is
recommended and more intuitive behaviour than the default (where integers are still represented as
doubles).

packages/cloudscape-react-ts-website/src/cloudscape-react-ts-website-project.ts

@@ -132,12 +132,12 @@ export class CloudscapeReactTsWebsiteProject extends ReactTypeScriptProject {
     this.addDevDeps("@types/swagger-ui-react");
     this.addDeps("swagger-ui-react", "aws4fetch");
 
-    tsApi.model.postCompileTask.exec(
-      `cp .api.json ${path.relative(
-        tsApi.model.outdir,
-        this.outdir
-      )}/public/api.json`
-    );
+    const targetApiSpecPath = `${path.relative(
+      tsApi.model.outdir,
+      this.outdir
+    )}/public/api.json`;
+    tsApi.model.postCompileTask.exec(`rm -f ${targetApiSpecPath}`);
+    tsApi.model.postCompileTask.exec(`cp .api.json ${targetApiSpecPath}`);
   }
 
   private buildSampleDirEntries(

packages/type-safe-api/scripts/generators/typescript/templates/interceptors.mustache

@@ -21,13 +21,11 @@ export const buildTryCatchInterceptor = <TStatus extends number, ErrorResponseBo
   errorResponseBody: ErrorResponseBody,
 ) => async <
   RequestParameters,
-  RequestArrayParameters,
   RequestBody,
   Response extends OperationResponse<number, any>,
 >(
   request: ChainedRequestInput<
   RequestParameters,
-  RequestArrayParameters,
   RequestBody,
   Response
   >,
@@ -77,22 +75,28 @@ const DEFAULT_CORS_HEADERS: { [key: string]: string } = {
  * Create an interceptor for adding headers to the response
  * @param additionalHeaders headers to add to the response
  */
-export const buildResponseHeaderInterceptor = (additionalHeaders: { [key: string]: string }) => async <
-  RequestParameters,
-  RequestArrayParameters,
-  RequestBody,
-  Response extends OperationResponse<number, any>
->(
-  request: ChainedRequestInput<RequestParameters, RequestArrayParameters, RequestBody, Response>,
-): Promise<Response> => {
-  const result = await request.chain.next(request);
-  return {
-    ...result,
-    headers: {
-      ...additionalHeaders,
-      ...result.headers,
-    },
+export const buildResponseHeaderInterceptor = (additionalHeaders: { [key: string]: string }) => {
+  const interceptor = async <
+    RequestParameters,
+    RequestBody,
+    Response extends OperationResponse<number, any>
+  >(
+    request: ChainedRequestInput<RequestParameters, RequestBody, Response>,
+  ): Promise<Response> => {
+    const result = await request.chain.next(request);
+    return {
+      ...result,
+      headers: {
+        ...additionalHeaders,
+        ...result.headers,
+      },
+    };
   };
+
+  // Any error responses returned during request validation will include the headers
+  (interceptor as any).__type_safe_api_response_headers = additionalHeaders;
+
+  return interceptor;
 };
 
 /**
@@ -124,7 +128,7 @@ export class LoggingInterceptor {
     RequestBody,
     Response extends OperationResponse<number, any>
   >(
-    request: ChainedRequestInput<RequestParameters, RequestArrayParameters, RequestBody, Response>,
+    request: ChainedRequestInput<RequestParameters, RequestBody, Response>,
   ): Promise<Response> => {
     logger.addContext(request.context);
     logger.appendKeys({ operationId: request.interceptorContext.operationId });
@@ -142,7 +146,7 @@ export class LoggingInterceptor {
     RequestArrayParameters,
     RequestBody,
     Response extends OperationResponse<number, any>
-  >(request: ChainedRequestInput<RequestParameters, RequestArrayParameters, RequestBody, Response>): Logger => {
+  >(request: ChainedRequestInput<RequestParameters, RequestBody, Response>): Logger => {
     if (!request.interceptorContext.logger) {
       throw new Error('No logger found, did you configure the LoggingInterceptor?');
     }
@@ -176,11 +180,10 @@ export interface TracingInterceptorOptions {
  */
 export const buildTracingInterceptor = (options?: TracingInterceptorOptions) => async <
   RequestParameters,
-  RequestArrayParameters,
   RequestBody,
   Response extends OperationResponse<number, any>
 >(
-  request: ChainedRequestInput<RequestParameters, RequestArrayParameters, RequestBody, Response>,
+  request: ChainedRequestInput<RequestParameters, RequestBody, Response>,
 ): Promise<Response> => {
   const handler = request.interceptorContext.operationId ?? process.env._HANDLER ?? 'index.handler';
   const segment = tracer.getSegment();
@@ -233,7 +236,7 @@ export class TracingInterceptor {
     RequestBody,
     Response extends OperationResponse<number, any>
   >(
-    request: ChainedRequestInput<RequestParameters, RequestArrayParameters, RequestBody, Response>,
+    request: ChainedRequestInput<RequestParameters, RequestBody, Response>,
   ): Tracer => {
     if (!request.interceptorContext.tracer) {
       throw new Error('No tracer found, did you configure the TracingInterceptor?');
@@ -265,7 +268,7 @@ export class MetricsInterceptor {
     RequestBody,
     Response extends OperationResponse<number, any>
   >(
-    request: ChainedRequestInput<RequestParameters, RequestArrayParameters, RequestBody, Response>,
+    request: ChainedRequestInput<RequestParameters, RequestBody, Response>,
   ): Promise<Response> => {
     metrics.addDimension("operationId", request.interceptorContext.operationId);
     request.interceptorContext.metrics = metrics;
@@ -286,7 +289,7 @@ export class MetricsInterceptor {
     RequestBody,
     Response extends OperationResponse<number, any>
   >(
-    request: ChainedRequestInput<RequestParameters, RequestArrayParameters, RequestBody, Response>,
+    request: ChainedRequestInput<RequestParameters, RequestBody, Response>,
   ): Metrics => {
     if (!request.interceptorContext.metrics) {
       throw new Error('No metrics logger found, did you configure the MetricsInterceptor?');