Configuration for body parsing size limit

packages/next-server/server/api-utils.ts

@@ -17,6 +17,7 @@ export async function apiResolver(
   resolverModule: any
 ) {
   try {
+    let config: PageConfig = {}
     let bodyParser = true
     if (!resolverModule) {
       res.statusCode = 404
@@ -25,7 +26,7 @@ export async function apiResolver(
     }
 
     if (resolverModule.config) {
-      const config: PageConfig = resolverModule.config
+      config = resolverModule.config
       if (config.api && config.api.bodyParser === false) {
         bodyParser = false
       }
@@ -36,7 +37,12 @@ export async function apiResolver(
     setLazyProp({ req, params }, 'query', getQueryParser(req))
     // // Parsing of body
     if (bodyParser) {
-      req.body = await parseBody(req)
+      req.body = await parseBody(
+        req,
+        config.api && config.api.bodyParser && config.api.bodyParser.sizeLimit
+          ? config.api.bodyParser.sizeLimit
+          : '1mb'
+      )
     }
 
     res.status = statusCode => sendStatusCode(res, statusCode)
@@ -59,7 +65,7 @@ export async function apiResolver(
  * Parse incoming message like `json` or `urlencoded`
  * @param req request object
  */
-export async function parseBody(req: NextApiRequest, limit: string = '1mb') {
+export async function parseBody(req: NextApiRequest, limit: string | number) {
   const contentType = parse(req.headers['content-type'] || 'text/plain')
   const { type, parameters } = contentType
   const encoding = parameters.charset || 'utf-8'

packages/next-server/types/index.d.ts

@@ -4,7 +4,11 @@
 export type PageConfig = {
   amp?: boolean | 'hybrid'
   api?: {
-    bodyParser?: boolean
+    /**
+     * The byte limit of the body. This is the number of bytes or any string
+     * format supported by `bytes`, for example `1000`, `'500kb'` or `'3mb'`.
+     */
+    bodyParser?: { sizeLimit?: number | string } | false
   }
   experimentalPrerender?: boolean | 'inline' | 'legacy'
 }

packages/next/README.md

@@ -1108,7 +1108,7 @@ Those middlewares are:
 - `req.query` - an object containing the [query string](https://en.wikipedia.org/wiki/Query_string). Defaults to `{}`
 - `req.body` - an object containing the body parsed by `content-type`, or `null` if no body is sent
 
-Body parsing is enabled by default.
+Body parsing is enabled by default with a size limit of `1mb` for the parsed body.
 You can opt-out of automatic body parsing if you need to consume it as a `Stream`:
 
 ```js
@@ -1124,6 +1124,23 @@ export const config = {
 }
 ```
 
+You can adjust size of parsed body by adding `sizeLimit` key to `bodyParser`, supported values are by [bytes](https://github.com/visionmedia/bytes.js) library.
+
+```js
+// ./pages/api/my-endpoint.js
+export default (req, res) => {
+  // ...
+}
+
+export const config = {
+  api: {
+    bodyParser: {
+      sizeLimit: '1mb',
+    }
+  },
+}
+```
+
 As an added bonus, you can also use any [Micro](https://github.com/zeit/micro) compatible [middleware](https://github.com/amio/awesome-micro)!
 
 For example, [configuring CORS](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS) for your API endpoint can be done leveraging `micro-cors`.

test/integration/api-support/pages/api/big-parse.js

@@ -0,0 +1,11 @@
+export const config = {
+  api: {
+    bodyParser: {
+      sizeLimit: '5mb'
+    }
+  }
+}
+
+export default (req, res) => {
+  res.status(200).json(req.body)
+}

test/integration/api-support/test/index.test.js

@@ -97,6 +97,18 @@ function runTests (serverless = false) {
     expect(data.statusText).toEqual('Body exceeded 1mb limit')
   })
 
+  it('should parse bigger body then 1mb', async () => {
+    const data = await fetchViaHTTP(appPort, '/api/big-parse', null, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json; charset=utf-8'
+      },
+      body: JSON.stringify(json)
+    })
+
+    expect(data.status).toEqual(200)
+  })
+
   it('should parse urlencoded body', async () => {
     const body = {
       title: 'Nextjs',