fix(middlewares/http-json-body-parser): narrow body type to string

packages/http-json-body-parser/index.d.ts

@@ -1,21 +1,13 @@
 import middy from '@middy/core'
 import { APIGatewayEvent, APIGatewayProxyEventV2 } from 'aws-lambda'
-import { JsonValue } from 'type-fest'
 
 interface Options {
   reviver?: (key: string, value: any) => any
   disableContentTypeError?: boolean
 }
 
-type VersionedApiGatewayEvent = APIGatewayEvent | APIGatewayProxyEventV2
+export type VersionedApiGatewayEvent = APIGatewayEvent | APIGatewayProxyEventV2
 
-export type Event<APIGatewayEventType extends VersionedApiGatewayEvent = VersionedApiGatewayEvent> = Omit<APIGatewayEventType, 'body'> & {
-  /**
-   * The body of the HTTP request.
-   */
-  body: JsonValue
-}
-
-declare function jsonBodyParser<APIGatewayEventType extends VersionedApiGatewayEvent = VersionedApiGatewayEvent> (options?: Options): middy.MiddlewareObj<Event<APIGatewayEventType>>
+declare function jsonBodyParser<APIGatewayEventType extends VersionedApiGatewayEvent = VersionedApiGatewayEvent> (options?: Options): middy.MiddlewareObj<APIGatewayEventType>
 
 export default jsonBodyParser

packages/http-json-body-parser/index.test-d.ts

@@ -1,20 +1,82 @@
 import { APIGatewayEvent, APIGatewayProxyEventV2 } from 'aws-lambda'
 import middy from '@middy/core'
 import { expectType } from 'tsd'
-import jsonBodyParser, { Event } from '.'
+import jsonBodyParser from '.'
 
 // use with default options
 let middleware = jsonBodyParser()
-expectType<middy.MiddlewareObj<Event>>(middleware)
+expectType<middy.MiddlewareObj<APIGatewayEvent | APIGatewayProxyEventV2>>(middleware)
 
 // use with all options
 middleware = jsonBodyParser({
   reviver: (key: string, value: any) => Boolean(value)
 })
-expectType<middy.MiddlewareObj<Event>>(middleware)
+expectType<middy.MiddlewareObj<APIGatewayEvent | APIGatewayProxyEventV2>>(middleware)
+
+const baseEvent: Omit<APIGatewayEvent, 'body'> = {
+  headers: {},
+  isBase64Encoded: false,
+  httpMethod: 'GET',
+  path: '/',
+  multiValueHeaders: {},
+  pathParameters: null,
+  queryStringParameters: null,
+  multiValueQueryStringParameters: null,
+  stageVariables: null,
+  requestContext: {
+    accountId: '',
+    apiId: '',
+    authorizer: null,
+    protocol: '',
+    httpMethod: '',
+    path: '',
+    stage: '',
+    requestId: '',
+    requestTimeEpoch: 0,
+    resourceId: '',
+    resourcePath: '',
+    identity: {
+      accessKey: null,
+      accountId: null,
+      apiKey: null,
+      apiKeyId: null,
+      caller: null,
+      clientCert: null,
+      cognitoAuthenticationProvider: null,
+      cognitoAuthenticationType: null,
+      cognitoIdentityId: null,
+      cognitoIdentityPoolId: null,
+      principalOrgId: null,
+      sourceIp: '',
+      user: null,
+      userAgent: null,
+      userArn: null
+    }
+  },
+  resource: ''
+}
+
+// allow body to only be string or null
+middleware = jsonBodyParser()
+const middifiedHandler = middy(() => {}).use(middleware)
+
+expectType<Promise<void>>(middifiedHandler({
+  ...baseEvent,
+  body: 'string'
+}, {} as any))
+expectType<Promise<void>>(middifiedHandler({
+  ...baseEvent,
+  body: null
+}, {} as any))
+
+middifiedHandler({
+  ...baseEvent,
+  // @ts-expect-error
+  body: {}
+}, {} as any).then(() => {}).catch(() => {})
 
 // allow specifying the event type
 const apiGatewayV1Middleware = jsonBodyParser<APIGatewayEvent>()
-expectType<middy.MiddlewareObj<Event<APIGatewayEvent>>>(apiGatewayV1Middleware)
+expectType<middy.MiddlewareObj<APIGatewayEvent>>(apiGatewayV1Middleware)
 const apiGatewayV2Middleware = jsonBodyParser<APIGatewayProxyEventV2>()
-expectType<middy.MiddlewareObj<Event<APIGatewayProxyEventV2>>>(apiGatewayV2Middleware)
+expectType<middy.MiddlewareObj<APIGatewayProxyEventV2>>(apiGatewayV2Middleware)