feat: add maxReturnSize option

README.md

@@ -113,6 +113,11 @@ Provide a max-age in milliseconds for HTTP caching, defaults to 0.
 This can also be a string accepted by the
 [ms](https://www.npmjs.org/package/ms#readme) module.
 
+##### maxChunkSize
+
+Specify maximum chunk size, defaults to send the entire file size.
+This will be used when `acceptRanges` is true.
+
 ##### root
 
 Serve files relative to `path`.

lib/send.js

@@ -130,12 +130,17 @@ function normalizeOptions (options) {
 
   const maxage = normalizeMaxAge(options.maxAge ?? options.maxage)
 
+  const maxChunkSize = options.acceptRanges !== undefined
+    ? Number(options.maxChunkSize)
+    : null
+
   const root = options.root
     ? resolve(options.root)
     : null
 
   return {
     acceptRanges,
+    maxChunkSize,
     cacheControl,
     etag,
     dotfiles,
@@ -546,6 +551,9 @@ function sendFileDirectly (request, path, stat, options) {
 
           // Content-Range
           statusCode = 206
+          if (options.maxChunkSize) {
+            ranges[0].end = Math.min(ranges[0].end, ranges[0].start + options.maxChunkSize - 1)
+          }
           headers['Content-Range'] = contentRange('bytes', len, ranges[0])
 
           // adjust for requested range

test/send.1.test.js

@@ -16,7 +16,7 @@ test('send(file, options)', function (t) {
   t.plan(10)
 
   t.test('acceptRanges', function (t) {
-    t.plan(2)
+    t.plan(6)
 
     t.test('should support disabling accept-ranges', function (t) {
       t.plan(2)
@@ -37,6 +37,54 @@ test('send(file, options)', function (t) {
         .expect(shouldNotHaveHeader('Content-Range', t))
         .expect(200, '123456789', err => t.error(err))
     })
+
+    t.test('should limit chunk size /1', function (t) {
+      t.plan(4)
+
+      request(createServer({ acceptRanges: true, maxChunkSize: 1, root: fixtures }))
+        .get('/nums.txt')
+        .set('Range', 'bytes=0-2')
+        .expect((res) => t.equal(res.headers['accept-ranges'], 'bytes'))
+        .expect((res) => t.equal(res.headers['content-range'], 'bytes 0-0/9'))
+        .expect((res) => t.equal(res.headers['content-length'], '1', 'should content-length must be as same as maxChunkSize'))
+        .expect(206, '1', (err) => t.error(err))
+    })
+
+    t.test('should limit chunk size /2', function (t) {
+      t.plan(4)
+
+      request(createServer({ acceptRanges: true, maxChunkSize: 1, root: fixtures }))
+        .get('/nums.txt')
+        .set('Range', 'bytes=1-2')
+        .expect((res) => t.equal(res.headers['accept-ranges'], 'bytes'))
+        .expect((res) => t.equal(res.headers['content-range'], 'bytes 1-1/9'))
+        .expect((res) => t.equal(res.headers['content-length'], '1', 'should content-length must be as same as maxChunkSize'))
+        .expect(206, '2', (err) => t.error(err))
+    })
+
+    t.test('should limit chunk size /3', function (t) {
+      t.plan(4)
+
+      request(createServer({ acceptRanges: true, maxChunkSize: 1, root: fixtures }))
+        .get('/nums.txt')
+        .set('Range', 'bytes=1-3')
+        .expect((res) => t.equal(res.headers['accept-ranges'], 'bytes'))
+        .expect((res) => t.equal(res.headers['content-range'], 'bytes 1-1/9'))
+        .expect((res) => t.equal(res.headers['content-length'], '1', 'should content-length must be as same as maxChunkSize'))
+        .expect(206, '2', (err) => t.error(err))
+    })
+
+    t.test('should limit chunk size /4', function (t) {
+      t.plan(4)
+
+      request(createServer({ acceptRanges: true, maxChunkSize: 4, root: fixtures }))
+        .get('/nums.txt')
+        .set('Range', 'bytes=1-2,3-6')
+        .expect((res) => t.equal(res.headers['accept-ranges'], 'bytes'))
+        .expect((res) => t.equal(res.headers['content-range'], 'bytes 1-4/9'))
+        .expect((res) => t.equal(res.headers['content-length'], '4', 'should content-length must be as same as maxChunkSize'))
+        .expect(206, '2345', (err) => t.error(err))
+    })
   })
 
   t.test('cacheControl', function (t) {

test/utils.js

@@ -9,6 +9,12 @@ module.exports.shouldNotHaveHeader = function shouldNotHaveHeader (header, t) {
   }
 }
 
+module.exports.shouldHaveHeader = function shouldHaveHeader (header, t) {
+  return function (res) {
+    t.ok((header.toLowerCase() in res.headers), 'should have header ' + header)
+  }
+}
+
 module.exports.createServer = function createServer (opts, fn) {
   return http.createServer(async function onRequest (req, res) {
     try {

types/index.d.ts

@@ -100,6 +100,11 @@ declare namespace send {
      */
     maxAge?: string | number | undefined;
 
+    /**
+     * Limit max response size when acceptRanges is true, defaults to the entire file size.
+     */
+    maxChunkSize?: number | undefined;
+
     /**
      * Serve files relative to path.
      */

types/index.test-d.ts

@@ -14,6 +14,8 @@ const req: any = {}
 
 {
   const result = await send(req, '/test.html', {
+    acceptRanges: true,
+    maxChunkSize: 10,
     immutable: true,
     maxAge: 0,
     root: __dirname + '/wwwroot'
@@ -53,4 +55,4 @@ switch (result.type) {
     expectType<ErrorSendResult>(result)
     expectType<Error>(result.metadata.error)
   }
-}
+}