src/validateResponse.spec.ts

@@ -1,28 +1,48 @@
+import { HttpStatusCode } from '@hello.nrfcloud.com/proto/hello'
 import middy from '@middy/core'
 import { Type } from '@sinclair/typebox'
 import type { Context } from 'aws-lambda'
 import assert from 'node:assert'
 import { describe, it } from 'node:test'
+import { aResponse } from './aResponse.js'
 import {
 	ResponseValidationFailedError,
 	validateResponse,
 } from './validateResponse.js'
 
 void describe('validateResponse()', () => {
 	void it('should validate the response', async () =>
-		assert.equal(
+		assert.deepEqual(
 			await middy()
-				.use(validateResponse(Type.Boolean({ title: 'A boolean' })))
-				.handler(async () => true)('Some event', {} as Context),
-			true,
+				.use(validateResponse(Type.Object({ value: Type.Boolean() })))
+				.handler(async () =>
+					aResponse(HttpStatusCode.OK, {
+						'@context': new URL('https://example.com'),
+						value: true,
+					}),
+				)('Some event', {} as Context),
+			{
+				body: '{"@context":"https://example.com/","value":true}',
+				headers: {
+					'Cache-Control': 'public, max-age=60',
+					'content-length': '48',
+					'content-type': 'application/json',
+				},
+				statusCode: 200,
+			},
 		))
 
 	void it('should throw an Error in case the response is invalid', async () =>
 		assert.rejects(
 			async () =>
 				middy()
-					.use(validateResponse(Type.Boolean()))
-					.handler(async () => 42)('Some event', {} as Context),
+					.use(validateResponse(Type.Object({ value: Type.Boolean() })))
+					.handler(async () =>
+						aResponse(HttpStatusCode.OK, {
+							'@context': new URL('https://example.com'),
+							value: 42,
+						}),
+					)('Some event', {} as Context),
 			ResponseValidationFailedError,
 		))
 })

src/validateResponse.ts

@@ -5,6 +5,7 @@ import {
 import type middy from '@middy/core'
 import type { TSchema } from '@sinclair/typebox'
 import type { ValueError } from '@sinclair/typebox/errors'
+import { tryAsJSON } from './tryAsJSON.js'
 import { ValidationFailedError } from './validateInput.js'
 
 export class ResponseValidationFailedError extends ValidationFailedError {
@@ -14,25 +15,37 @@ export class ResponseValidationFailedError extends ValidationFailedError {
 	}
 }
 
+/**
+ * Validate responses created with `aResponse`
+ */
 export const validateResponse = <ResponseSchema extends TSchema>(
 	schema: ResponseSchema,
 ): middy.MiddlewareObj => {
 	const validator = validateWithTypeBox(schema)
 	return {
 		after: async (req) => {
-			const maybeValid = validator(req.response)
+			const body = req.response?.body
+			if ((body?.length ?? 0) === 0) {
+				console.debug(`[validateResponse]`, `Response body is empty`)
+			}
+			if (
+				(req.response.headers['content-type']?.includes('application/json') ??
+					false) === false
+			) {
+				console.debug(`[validateResponse]`, `Response body is not JSON`)
+			}
+			const maybeValid = validator(tryAsJSON(req.response.body))
 			if ('errors' in maybeValid) {
 				console.error(
 					`[validateResponse]`,
 					`Response validation failed`,
-					JSON.stringify({
-						response: req.response,
-						errors: formatTypeBoxErrors(maybeValid.errors),
-					}),
+					req.response.body,
+					formatTypeBoxErrors(maybeValid.errors),
+					schema.title,
 				)
 				throw new ResponseValidationFailedError(maybeValid.errors)
 			}
-			console.debug(`[validateResponse]`, `Response is`, schema.title)
+			console.debug(`[validateResponse]`, `Response is valid`, schema.title)
 			return undefined
 		},
 	}