refactor: monkey patch 'form-data' replaces 'formdata-node' (#1547)

* if form-data lib adds 'any' new method included in monkey patch,
  monkey patch will fail

* update http-multipart tests for compatibility with form-data patch
* live tests also refactored, remain in skip state
* tested on node 8


Co-authored-by: Vladimir Gorej <vladimir.gorej@gmail.com>

Author: tim-lai

package-lock.json

@@ -98,14 +98,14 @@
   "dependencies": {
     "@babel/runtime-corejs2": "^7.0.0",
     "@kyleshockey/object-assign-deep": "^0.4.0",
-    "@tim-lai/isomorphic-form-data": "^1.0.0",
     "btoa": "1.1.2",
     "buffer": "^5.1.0",
     "cookie": "^0.3.1",
     "cross-fetch": "^3.0.4",
     "deep-extend": "^0.5.1",
     "encode-3986": "^1.0.0",
     "fast-json-patch": "~2.1.0",
+    "isomorphic-form-data": "^2.0.0",
     "js-yaml": "^3.13.1",
     "lodash": "^4.17.14",
     "qs": "^6.3.0",

package.json

@@ -3,7 +3,7 @@ import qs from 'qs'
 import jsYaml from 'js-yaml'
 import isString from 'lodash/isString'
 import isFunction from 'lodash/isFunction'
-import FormData from '@tim-lai/isomorphic-form-data'
+import FormData from './internal/form-data-monkey-patch'
 
 // For testing
 export const self = {

src/http.js

@@ -0,0 +1,74 @@
+import isFunction from 'lodash/isFunction'
+import IsomorphicFormData from 'isomorphic-form-data'
+
+// patches FormData type by mutating it.
+// patch :: FormData -> PatchedFormData
+export const patch = (FormData) => {
+  const createEntry = (field, value) => ({name: field, value})
+  /** We return original type if prototype already contains one of methods we're trying to patch.
+   * Reasoning: if one of the methods already exists, it would access data in other
+   * property than our `_entryList`. That could potentially create nasty
+   * hardly detectable bugs if `form-data` library implements only couple of
+   * methods that it misses, instead of implementing all of them.
+   * Current solution will fail the tests to let us know that form-data library
+   * already implements some of the methods that we try to monkey-patch, and our
+   * monkey-patch code should then compensate the library changes easily.
+   */
+  if (
+    isFunction(FormData.prototype.set)
+    || isFunction(FormData.prototype.get)
+    || isFunction(FormData.prototype.getAll)
+    || isFunction(FormData.prototype.has)
+  ) {
+    return FormData
+  }
+  class PatchedFormData extends FormData {
+    constructor(form) {
+      super(form)
+      this._entryList = []
+    }
+
+    append(field, value, options) {
+      this._entryList.push(createEntry(field, value))
+      return super.append(field, value, options)
+    }
+
+    set(field, value) {
+      const newEntry = createEntry(field, value)
+
+      this._entryList = this._entryList.filter((entry) => {
+        return entry.name !== field
+      })
+
+      this._entryList.push(newEntry)
+    }
+
+    get(field) {
+      const foundEntry = this._entryList.find((entry) => {
+        return entry.name === field
+      })
+
+      return foundEntry === undefined ? null : foundEntry
+    }
+
+    getAll(field) {
+      return this._entryList
+        .filter((entry) => {
+          return entry.name === field
+        })
+        .map((entry) => {
+          return entry.value
+        })
+    }
+
+    has(field) {
+      return this._entryList.some((entry) => {
+        return entry.name === field
+      })
+    }
+  }
+
+  return PatchedFormData
+}
+
+export default patch(IsomorphicFormData)

src/internal/form-data-monkey-patch.js

@@ -1,4 +1,4 @@
-import FormData from '@tim-lai/isomorphic-form-data'
+import FormData from '../../src/internal/form-data-monkey-patch'
 import {execute, buildRequest, baseUrl, self as stubs} from '../../src/execute'
 import {normalizeSwagger} from '../../src/helpers'
 

test/execute/main.js

@@ -1,5 +1,5 @@
-import FormData from '@tim-lai/isomorphic-form-data'
 import fetchMock from 'fetch-mock'
+import FormData from '../src/internal/form-data-monkey-patch'
 import {buildRequest} from '../src/execute'
 import sampleMultipartOpenApi2 from './data/sample-multipart-oas2'
 import sampleMultipartOpenApi3 from './data/sample-multipart-oas3'
@@ -52,16 +52,15 @@ describe('buildRequest - openapi 2.0', () => {
     test.skip('should (Live) POST multipart-formdata with entry item entries', () => {
       return fetch('http://localhost:3300/api/v1/formdata', { // eslint-disable-line no-undef
         method: 'POST',
-        body: req.body.stream, // per formdata-node docs
-        headers: req.body.headers // per formdata-node docs
+        body: req.body
       })
         .then((res) => {
           return res.json()
         })
         .then((json) => {
-          expect(json.email.length).toEqual(2)
-          expect(json.email[0]).toEqual('person1')
-          expect(json.email[1]).toEqual('person2')
+          expect(json.data.email.length).toEqual(2)
+          expect(json.data.email[0]).toEqual('person1')
+          expect(json.data.email[1]).toEqual('person2')
         })
     })
 
@@ -84,8 +83,7 @@ describe('buildRequest - openapi 2.0', () => {
 
       return fetch('http://localhost:3300/api/v1/formdata', { // eslint-disable-line no-undef
         method: 'POST',
-        body: req.body.stream, // per formdata-node docs
-        headers: req.body.headers // per formdata-node docs
+        body: req.body,
       })
         .then((res) => {
           return res.json()
@@ -94,10 +92,10 @@ describe('buildRequest - openapi 2.0', () => {
           expect(json.data.email.length).toEqual(2)
           expect(json.data.email[0]).toEqual('person1')
           expect(json.data.email[1]).toEqual('person2')
-          // duck typing that fetch received a formdata-node Stream instead of plain object
+          // duck typing that fetch received a FormData instance instead of plain object
           const lastOptions = fetchMock.lastOptions()
           expect(lastOptions.body.readable).toEqual(true)
-          expect(lastOptions.body._readableState).toBeDefined()
+          // expect(lastOptions.body._streams).toBeDefined()
         })
     })
   })
@@ -139,16 +137,15 @@ describe('buildRequest - openapi 3.0', () => {
     test.skip('should (Live) POST multipart-formdata with entry item entries', () => {
       return fetch('http://localhost:3300/api/v1/formdata', { // eslint-disable-line no-undef
         method: 'POST',
-        body: req.body.stream, // per formdata-node docs
-        headers: req.body.headers // per formdata-node docs
+        body: req.body
       })
       .then((res) => {
         return res.json()
       })
       .then((json) => {
-        expect(json.email.length).toEqual(2)
-        expect(json.email[0]).toEqual('person1')
-        expect(json.email[1]).toEqual('person2')
+        expect(json.data.email.length).toEqual(2)
+        expect(json.data.email[0]).toEqual('person1')
+        expect(json.data.email[1]).toEqual('person2')
       })
     })
 
@@ -171,8 +168,7 @@ describe('buildRequest - openapi 3.0', () => {
 
       return fetch('http://localhost:3300/api/v1/formdata', { // eslint-disable-line no-undef
         method: 'POST',
-        body: req.body.stream, // per formdata-node docs
-        headers: req.body.headers // per formdata-node docs
+        body: req.body,
       })
         .then((res) => {
           return res.json()
@@ -181,10 +177,10 @@ describe('buildRequest - openapi 3.0', () => {
           expect(json.data.email.length).toEqual(2)
           expect(json.data.email[0]).toEqual('person1')
           expect(json.data.email[1]).toEqual('person2')
-          // duck typing that fetch received a formdata-node Stream instead of plain object
+          // duck typing that fetch received a FormData instance instead of plain object
           const lastOptions = fetchMock.lastOptions()
           expect(lastOptions.body.readable).toEqual(true)
-          expect(lastOptions.body._readableState).toBeDefined()
+          // expect(lastOptions.body._streams).toBeDefined()
         })
     })
   })