feat(fomdata): added support for spec-compliant FormData & Blob types; (#5316)

lib/helpers/formDataToStream.js

@@ -0,0 +1,110 @@
+import {Readable} from 'stream';
+import utils from "../utils.js";
+import readBlob from "./readBlob.js";
+
+const BOUNDARY_ALPHABET = utils.ALPHABET.ALPHA_DIGIT + '-_';
+
+const textEncoder = new TextEncoder();
+
+const CRLF = '\r\n';
+const CRLF_BYTES = textEncoder.encode(CRLF);
+const CRLF_BYTES_COUNT = 2;
+
+class FormDataPart {
+  constructor(name, value) {
+    const {escapeName} = this.constructor;
+    const isStringValue = utils.isString(value);
+
+    let headers = `Content-Disposition: form-data; name="${escapeName(name)}"${
+      !isStringValue && value.name ? `; filename="${escapeName(value.name)}"` : ''
+    }${CRLF}`;
+
+    if (isStringValue) {
+      value = textEncoder.encode(String(value).replace(/\r?\n|\r\n?/g, CRLF));
+    } else {
+      headers += `Content-Type: ${value.type || "application/octet-stream"}${CRLF}`
+    }
+
+    this.headers = textEncoder.encode(headers + CRLF);
+
+    this.contentLength = isStringValue ? value.byteLength : value.size;
+
+    this.size = this.headers.byteLength + this.contentLength + CRLF_BYTES_COUNT;
+
+    this.name = name;
+    this.value = value;
+  }
+
+  async *encode(){
+    yield this.headers;
+
+    const {value} = this;
+
+    if(utils.isTypedArray(value)) {
+      yield value;
+    } else {
+      yield* readBlob(value);
+    }
+
+    yield CRLF_BYTES;
+  }
+
+  static escapeName(name) {
+      return String(name).replace(/[\r\n"]/g, (match) => ({
+        '\r' : '%0D',
+        '\n' : '%0A',
+        '"' : '%22',
+      }[match]));
+  }
+}
+
+const formDataToStream = (form, headersHandler, options) => {
+  const {
+    tag = 'form-data-boundary',
+    size = 25,
+    boundary = tag + '-' + utils.generateString(size, BOUNDARY_ALPHABET)
+  } = options || {};
+
+  if(!utils.isFormData(form)) {
+    throw TypeError('FormData instance required');
+  }
+
+  if (boundary.length < 1 || boundary.length > 70) {
+    throw Error('boundary must be 10-70 characters long')
+  }
+
+  const boundaryBytes = textEncoder.encode('--' + boundary + CRLF);
+  const footerBytes = textEncoder.encode('--' + boundary + '--' + CRLF + CRLF);
+  let contentLength = footerBytes.byteLength;
+
+  const parts = Array.from(form.entries()).map(([name, value]) => {
+    const part = new FormDataPart(name, value);
+    contentLength += part.size;
+    return part;
+  });
+
+  contentLength += boundaryBytes.byteLength * parts.length;
+
+  contentLength = utils.toFiniteNumber(contentLength);
+
+  const computedHeaders = {
+    'Content-Type': `multipart/form-data; boundary=${boundary}`
+  }
+
+  if (Number.isFinite(contentLength)) {
+    computedHeaders['Content-Length'] = contentLength;
+  }
+
+  headersHandler && headersHandler(computedHeaders);
+
+  return Readable.from((async function *() {
+    for(const part of parts) {
+      yield boundaryBytes;
+      yield* part.encode();
+    }
+
+    yield footerBytes;
+  })());
+};
+
+export default formDataToStream;

lib/helpers/readBlob.js

@@ -0,0 +1,15 @@
+const {asyncIterator} = Symbol;
+
+const readBlob = async function* (blob) {
+  if (blob.stream) {
+    yield* blob.stream()
+  } else if (blob.arrayBuffer) {
+    yield await blob.arrayBuffer()
+  } else if (blob[asyncIterator]) {
+    yield* asyncIterator.call(blob);
+  } else {
+    yield blob;
+  }
+}
+
+export default readBlob;

lib/helpers/toFormData.js

@@ -2,7 +2,8 @@
 
 import utils from '../utils.js';
 import AxiosError from '../core/AxiosError.js';
-import envFormData from '../env/classes/FormData.js';
+// temporary hotfix to avoid circular references until AxiosURLSearchParams is refactored
+import PlatformFormData from '../platform/node/classes/FormData.js';
 
 /**
  * Determines if the given thing is a array or js object.
@@ -59,17 +60,6 @@ const predicates = utils.toFlatObject(utils, {}, null, function filter(prop) {
   return /^is[A-Z]/.test(prop);
 });
 
-/**
- * If the thing is a FormData object, return true, otherwise return false.
- *
- * @param {unknown} thing - The thing to check.
- *
- * @returns {boolean}
- */
-function isSpecCompliant(thing) {
-  return thing && utils.isFunction(thing.append) && thing[Symbol.toStringTag] === 'FormData' && thing[Symbol.iterator];
-}
-
 /**
  * Convert a data object to FormData
  *
@@ -99,7 +89,7 @@ function toFormData(obj, formData, options) {
   }
 
   // eslint-disable-next-line no-param-reassign
-  formData = formData || new (envFormData || FormData)();
+  formData = formData || new (PlatformFormData || FormData)();
 
   // eslint-disable-next-line no-param-reassign
   options = utils.toFlatObject(options, {
@@ -117,7 +107,7 @@ function toFormData(obj, formData, options) {
   const dots = options.dots;
   const indexes = options.indexes;
   const _Blob = options.Blob || typeof Blob !== 'undefined' && Blob;
-  const useBlob = _Blob && isSpecCompliant(formData);
+  const useBlob = _Blob && utils.isSpecCompliantForm(formData);
 
   if (!utils.isFunction(visitor)) {
     throw new TypeError('visitor must be a function');