feat: enable request type coercion (#84)

* fix: allow reject on start

* feat: enable request coercion

server/package.json

@@ -15,6 +15,7 @@
     "body-parser": "^1.19.0",
     "express": "^4.16.4",
     "mz": "^2.7.0",
+    "openapi-request-coercer": "^2.3.0",
     "swagger-ui-express": "^4.0.2",
     "uuid": "^3.3.2"
   },

server/src/RequestCoercer.ts

@@ -0,0 +1,15 @@
+import { SlushyContext } from './SlushyContext'
+import OpenApiRequestCoercer from 'openapi-request-coercer'
+
+export class RequestCoercer<TContext> {
+    /**
+     * @note Modifies the request object.
+     */
+    public coerce(context: SlushyContext<TContext>): void {
+        const coercer = new OpenApiRequestCoercer({
+            enableObjectCoercion: true,
+            parameters: context.operationObject.parameters || [],
+        })
+        coercer.coerce(context.req)
+    }
+}

server/src/Slushy.ts

@@ -15,7 +15,9 @@ export class Slushy<TContext> {
     ) {}
 
     public async start(port: number) {
-        return new Promise(resolve => this.app.listen(port, resolve))
+        return new Promise((resolve, reject) =>
+            this.app.listen(port, (error: Error) => (error ? resolve() : reject(error)))
+        )
     }
 
     public async initialise() {

server/src/SlushyRouter.ts

@@ -7,6 +7,7 @@ import { RequestParametersExtractor } from './RequestParametersExtractor'
 import { ContextFactory } from './ContextFactory'
 import { ApiDoc } from './middleware/ApiDoc'
 import * as UUID from 'uuid'
+import { RequestCoercer } from './RequestCoercer'
 
 export type RouteHandler<TParams, TResponse, TContext> = (
     params: TParams,
@@ -19,6 +20,7 @@ export class SlushyRouter<TContext> {
         public readonly router: SlushyRouterImplementation,
         private readonly requestParameterExtractor = new RequestParametersExtractor(),
         private readonly contextFactory = new ContextFactory<TContext>(),
+        private readonly requestCoercer = new RequestCoercer<TContext>(),
         private readonly openApiBridge = new OpenApiBridge()
     ) {
         // TODO: Move this somewhere else.
@@ -76,6 +78,7 @@ export class SlushyRouter<TContext> {
                     openApi,
                     contextFactory
                 )
+                this.requestCoercer.coerce(context)
                 const parameters = await this.requestParameterExtractor.getParameters<TParams>(context)
                 // FIXME: Remove cast again for type safety.
                 const resourceResponse = ((await handler(parameters, context)) as unknown) as {

server/yarn.lock

@@ -1425,6 +1425,13 @@ onetime@^2.0.0:
   dependencies:
     mimic-fn "^1.0.0"
 
+openapi-request-coercer@^2.3.0:
+  version "2.3.0"
+  resolved "https://registry.npmjs.org/openapi-request-coercer/-/openapi-request-coercer-2.3.0.tgz#2f756ed027251fb857ade9a116356d59613cce0b"
+  integrity sha512-oLrxgYOS3CE+ystqeZEBlpxiuQy6Q5HNLMLj9ciMGdJL7x73NedVWkEU00RJ8acjqZJEm73IYMRhQ0D4De14/A==
+  dependencies:
+    openapi-types "1.3.4"
+
 [email protected]:
   version "1.3.4"
   resolved "https://registry.yarnpkg.com/openapi-types/-/openapi-types-1.3.4.tgz#e8c65be38d3b7d48fa84aa3d488d17505d3e30cd"