feat: support FormData (#286)

lib/form-data.js

@@ -0,0 +1,81 @@
+'use strict'
+
+const { randomUUID } = require('node:crypto')
+const { Readable } = require('node:stream')
+
+let textEncoder
+
+function isFormDataLike (payload) {
+  return (
+    payload &&
+    typeof payload === 'object' &&
+    typeof payload.append === 'function' &&
+    typeof payload.delete === 'function' &&
+    typeof payload.get === 'function' &&
+    typeof payload.getAll === 'function' &&
+    typeof payload.has === 'function' &&
+    typeof payload.set === 'function' &&
+    payload[Symbol.toStringTag] === 'FormData'
+  )
+}
+
+/*
+  partial code extraction and refactoring of `undici`.
+  MIT License. https://github.com/nodejs/undici/blob/043d8f1a89f606b1db259fc71f4c9bc8eb2aa1e6/lib/web/fetch/LICENSE
+  Reference https://github.com/nodejs/undici/blob/043d8f1a89f606b1db259fc71f4c9bc8eb2aa1e6/lib/web/fetch/body.js#L102-L168
+*/
+function formDataToStream (formdata) {
+  // lazy creation of TextEncoder
+  textEncoder = textEncoder ?? new TextEncoder()
+
+  // we expect the function argument must be FormData
+  const boundary = `----formdata-${randomUUID()}`
+  const prefix = `--${boundary}\r\nContent-Disposition: form-data`
+
+  /*! formdata-polyfill. MIT License. Jimmy Wärting <https://jimmy.warting.se/opensource> */
+  const escape = (str) =>
+    str.replace(/\n/g, '%0A').replace(/\r/g, '%0D').replace(/"/g, '%22')
+  const normalizeLinefeeds = (value) => value.replace(/\r?\n|\r/g, '\r\n')
+
+  const linebreak = new Uint8Array([13, 10]) // '\r\n'
+
+  async function * asyncIterator () {
+    for (const [name, value] of formdata) {
+      if (typeof value === 'string') {
+        // header
+        yield textEncoder.encode(`${prefix}; name="${escape(normalizeLinefeeds(name))}"\r\n\r\n`)
+        // body
+        yield textEncoder.encode(`${normalizeLinefeeds(value)}\r\n`)
+      } else {
+        let header = `${prefix}; name="${escape(normalizeLinefeeds(name))}"`
+        value.name && (header += `; filename="${escape(value.name)}"`)
+        header += `\r\nContent-Type: ${value.type || 'application/octet-stream'}\r\n\r\n`
+        // header
+        yield textEncoder.encode(header)
+        // body
+        /* istanbul ignore else */
+        if (value.stream) {
+          yield * value.stream()
+        } else {
+          // shouldn't be here since Blob / File should provide .stream
+          // and FormData always convert to USVString
+          /* istanbul ignore next */
+          yield value
+        }
+        yield linebreak
+      }
+    }
+    // end
+    yield textEncoder.encode(`--${boundary}--`)
+  }
+
+  const stream = Readable.from(asyncIterator())
+
+  return {
+    stream,
+    contentType: `multipart/form-data; boundary=${boundary}`
+  }
+}
+
+module.exports.isFormDataLike = isFormDataLike
+module.exports.formDataToStream = formDataToStream

lib/request.js

@@ -9,6 +9,7 @@ const assert = require('node:assert')
 const { createDeprecation } = require('process-warning')
 
 const parseURL = require('./parse-url')
+const { isFormDataLike, formDataToStream } = require('./form-data')
 const { EventEmitter } = require('node:events')
 
 // request.connectin deprecation https://nodejs.org/api/http.html#http_request_connection
@@ -146,7 +147,15 @@ function Request (options) {
 
   // we keep both payload and body for compatibility reasons
   let payload = options.payload || options.body || null
-  const payloadResume = payload && typeof payload.resume === 'function'
+  let payloadResume = payload && typeof payload.resume === 'function'
+
+  if (isFormDataLike(payload)) {
+    const stream = formDataToStream(payload)
+    payload = stream.stream
+    payloadResume = true
+    // we override the content-type
+    this.headers['content-type'] = stream.contentType
+  }
 
   if (payload && typeof payload !== 'string' && !payloadResume && !Buffer.isBuffer(payload)) {
     payload = JSON.stringify(payload)

package.json

@@ -14,14 +14,16 @@
     "@fastify/ajv-compiler": "^3.1.0",
     "@fastify/pre-commit": "^2.0.2",
     "@types/node": "^20.1.0",
-    "tinybench": "^2.5.1",
     "end-of-stream": "^1.4.4",
     "express": "^4.17.1",
     "form-auto-content": "^3.0.0",
     "form-data": "^4.0.0",
+    "formdata-node": "^4.4.1",
     "standard": "^17.0.0",
     "tap": "^16.0.0",
-    "tsd": "^0.31.0"
+    "tinybench": "^2.5.1",
+    "tsd": "^0.31.0",
+    "undici": "^5.28.4"
   },
   "scripts": {
     "benchmark": "node benchmark/benchmark.js",

test/index.test.js

@@ -13,7 +13,7 @@ const express = require('express')
 const inject = require('../index')
 const parseURL = require('../lib/parse-url')
 
-const FormData = require('form-data')
+const NpmFormData = require('form-data')
 const formAutoContent = require('form-auto-content')
 const httpMethods = [
   'delete',
@@ -1033,7 +1033,7 @@ test('form-data should be handled correctly', (t) => {
     })
   }
 
-  const form = new FormData()
+  const form = new NpmFormData()
   form.append('my_field', 'my value')
 
   inject(dispatch, {
@@ -2012,3 +2012,99 @@ test('request that is destroyed does not error', (t) => {
     t.equal(res.payload, 'hi')
   })
 })
+
+function runFormDataUnitTest (name, { FormData, Blob }) {
+  test(`${name} - form-data should be handled correctly`, (t) => {
+    t.plan(23)
+
+    const dispatch = function (req, res) {
+      let body = ''
+      t.ok(/multipart\/form-data; boundary=----formdata-[0-9a-fA-F]{8}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{12}(--)?$/.test(req.headers['content-type']), 'proper Content-Type provided')
+      req.on('data', d => {
+        body += d
+      })
+      req.on('end', () => {
+        res.end(body)
+      })
+    }
+
+    const form = new FormData()
+    form.append('field', 'value')
+    form.append('blob', new Blob(['value']), '')
+    form.append('blob-with-type', new Blob(['value'], { type: 'text/plain' }), '')
+    form.append('blob-with-name', new Blob(['value']), 'file.txt')
+    form.append('number', 1)
+
+    inject(dispatch, {
+      method: 'POST',
+      url: 'http://example.com:8080/hello',
+      payload: form
+    }, (err, res) => {
+      t.error(err)
+      t.equal(res.statusCode, 200)
+
+      const regexp = [
+      // header
+        /^------formdata-[0-9a-fA-F]{8}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{4}\b-[0-9a-fA-F]{12}(--)?$/,
+        // content-disposition
+        /^Content-Disposition: form-data; name="(.*)"(; filename="(.*)")?$/,
+        // content-type
+        /^Content-Type: (.*)$/
+      ]
+      const readable = Readable.from(res.body.split('\r\n'))
+      let i = 1
+      readable.on('data', function (chunk) {
+        switch (i) {
+          case 1:
+          case 5:
+          case 10:
+          case 15:
+          case 20: {
+          // header
+            t.ok(regexp[0].test(chunk), 'correct header')
+            break
+          }
+          case 2:
+          case 6:
+          case 11:
+          case 16: {
+          // content-disposition
+            t.ok(regexp[1].test(chunk), 'correct content-disposition')
+            break
+          }
+          case 7:
+          case 12:
+          case 17: {
+          // content-type
+            t.ok(regexp[2].test(chunk), 'correct content-type')
+            break
+          }
+          case 3:
+          case 8:
+          case 13:
+          case 18: {
+          // empty
+            t.equal(chunk, '', 'correct space')
+            break
+          }
+          case 4:
+          case 9:
+          case 14:
+          case 19: {
+          // value
+            t.equal(chunk, 'value', 'correct value')
+            break
+          }
+        }
+        i++
+      })
+    })
+  }, { skip: FormData == null || Blob == null })
+}
+
+// supports >= node@18
+runFormDataUnitTest('native', { FormData: globalThis.FormData, Blob: globalThis.Blob })
+// supports >= node@16
+runFormDataUnitTest('undici', { FormData: require('undici').FormData, Blob: require('node:buffer').Blob })
+// supports >= node@14
+runFormDataUnitTest('formdata-node', { FormData: require('formdata-node').FormData, Blob: require('formdata-node').Blob })