Fall back to text body (#96)

* Add guard for 204 (don't just rely on content length)

* Add specs

* Bump patch

* Add option to return text of body if parsing fails

* Add specs

* Update docs and version

__mocks__/isomorphic-fetch.js

@@ -11,22 +11,34 @@ const statuses = {
   [unauthorizedUrl]: 401
 }
 
-export default jest.fn(function (url, options) {
-  const { headers={} } = options
-  const body = { ...options, url }
+export class MockResponse {
+  #text
 
-  const response = {
-    // Response echoes back passed options
-    headers: {
-      get: (header) => {
-        return headers[header]
-      },
-      ...headers,
-    },
-    json: () => Promise.resolve(body),
-    ok: ![failureUrl, unauthorizedUrl].includes(url),
-    status: statuses[url]
+  constructor(url, options, body = null) {
+    const { headers={} } = options
+    this.headers = {
+      get: (header) => headers[header],
+      ...headers
+    }
+    this.body = body ?? { ...options, url }
+    this.ok = ![failureUrl, unauthorizedUrl].includes(url)
+    this.status = statuses[url]
+    this._config = options
+    this.#text = typeof body === 'string' ? body : JSON.stringify(this.body)
   }
+
+  json() {
+    return Promise.resolve(this.body)
+  }
+
+  text() {
+    return Promise.resolve(this.#text)
+  }
+}
+
+export default jest.fn(function fetch(url, options) {
+  const response = new MockResponse(url, options)
+
   // Simulate server response
   return new Promise((resolve, reject) => {
     setTimeout(

docs.md

@@ -171,6 +171,7 @@ In addition to the normal Fetch API settings, the config object may also contain
 -   `camelizeResponse`: A boolean flag indicating whether or not to camelize the response keys (default=`true`). The helper function that does this is also exported from this library as `camelizeKeys`.
 -   `decamelizeBody`: A boolean flag indicating whether or not to decamelize the body keys (default=`true`). The helper function that does this is also exported from this library as `decamelizeKeys`.
 -   `decamelizeQuery`: A boolean flag indicating whether or not to decamelize the query string keys (default=`true`).
+-   `parseJsonStrictly`: A boolean flag indicating whether or not to return the text of the response body if JSON parsing fails (default=`true`). If set to `true` and invalid JSON is received in the response, then `null` will be returned instead.
 -   `auth`: An object with the following keys `{ username, password }`. If present, `http` will use [basic auth][28], adding the header `"Authorization": "Basic <authToken>"` to the request, where `<authToken>` is a base64 encoded string of `username:password`.
 
 ### Parameters

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@launchpadlab/lp-requests",
-  "version": "4.1.9",
+  "version": "4.2.0",
   "description": "Request helpers",
   "main": "lib/index.js",
   "scripts": {

src/http/http.js

@@ -47,6 +47,7 @@ import {
  * - `camelizeResponse`: A boolean flag indicating whether or not to camelize the response keys (default=`true`). The helper function that does this is also exported from this library as `camelizeKeys`.
  * - `decamelizeBody`: A boolean flag indicating whether or not to decamelize the body keys (default=`true`). The helper function that does this is also exported from this library as `decamelizeKeys`.
  * - `decamelizeQuery`: A boolean flag indicating whether or not to decamelize the query string keys (default=`true`).
+ * - `parseJsonStrictly`: A boolean flag indicating whether or not to return the text of the response body if JSON parsing fails (default=`true`). If set to `true` and invalid JSON is received in the response, then `null` will be returned instead.
  * - `auth`: An object with the following keys `{ username, password }`. If present, `http` will use [basic auth](https://en.wikipedia.org/wiki/Basic_access_authentication#Client_side), adding the header `"Authorization": "Basic <authToken>"` to the request, where `<authToken>` is a base64 encoded string of `username:password`.
  *
  * @name http
@@ -85,15 +86,21 @@ export function parseArguments (...args) {
 }
 
 // Get JSON from response
-async function getResponseBody(response) {
+async function getResponseBody(response, { parseJsonStrictly }) {
   // Don't parse empty body
   if (response.headers.get('Content-Length') === '0' || response.status === 204) return null
+
+  let data
   try {
-    return await response.json()
+    data = await response.text()
+    return JSON.parse(data)
   } catch (e) {
-    // eslint-disable-next-line
-    console.warn('Failed to parse response body: ' + e, response)
-    return null
+    if (parseJsonStrictly) {
+      // eslint-disable-next-line
+      console.warn('Failed to parse response body: ' + e, response)
+      return null
+    }
+    return data
   }
 }
 
@@ -123,13 +130,14 @@ async function http (...args) {
     failureDataPath,
     url,
     fetchOptions,
+    parseJsonStrictly,
   } = parsedOptions
   // responseData is either the body of the response, or an error object.
   const responseData = await attemptAsync(async () => {
     // Make request
-    const response = await fetch(url, fetchOptions)
+    const response = __mock_response ?? await fetch(url, fetchOptions)
     // Parse the response
-    const body = __mock_response || await getResponseBody(response)
+    const body = await getResponseBody(response, { parseJsonStrictly })
     const data = camelizeResponse ? camelizeKeys(body) : body
     if (!response.ok) {
       const errors = getDataAtPath(data, failureDataPath)

src/http/middleware/set-defaults.js

@@ -3,10 +3,11 @@ import { identity } from '../../utils'
 const DEFAULTS = {
   credentials: 'same-origin',
   mode: 'same-origin',
-  onSuccess: identity, 
+  onSuccess: identity,
   onFailure: identity,
   camelizeResponse: true,
   failureDataPath: 'errors',
+  parseJsonStrictly: true,
 }
 
 const DEFAULT_HEADERS = {
@@ -25,4 +26,4 @@ function setDefaults ({ headers={}, overrideHeaders=false, ...rest }) {
   }
 }
 
-export default setDefaults
+export default setDefaults

test/http/http.test.js

@@ -1,5 +1,5 @@
 import Base64 from 'Base64'
-import { successUrl, noContentUrl, failureUrl } from 'isomorphic-fetch'
+import { successUrl, noContentUrl, failureUrl, MockResponse } from 'isomorphic-fetch'
 import { http } from '../../src'
 
 // These tests rely on the mock Fetch()
@@ -81,7 +81,7 @@ test('http modifies fetch configuration using `before` hook', () => {
 
 test('http modifies overall configuration using `before` hook', () => {
   const before = () => ({ successDataPath: 'foo' })
-  return http(successUrl, { before, __mock_response: { foo: 'bar' } }).then((res) => {
+  return httpWithMock(successUrl, { before }, { foo: 'bar' }).then((res) => {
     expect(res).toEqual('bar')
   })
 })
@@ -180,12 +180,11 @@ test('http pulls data from response using successDataPath', () => {
 test('http failureDataPath defaults to "errors"', () => {
   expect.assertions(1)
   const ERRORS = { 'someValue': 'there was an error' }
-  return http(failureUrl, {
+  return httpWithMock(failureUrl, {
     method: 'POST',
-    __mock_response: {
+  }, {
       errors: ERRORS,
-    }
-  }).catch((err) => {
+    }).catch((err) => {
     expect(err.errors).toEqual(ERRORS)
   })
 })
@@ -231,23 +230,21 @@ test('http does not decamelizes query if decamelizeQuery is false', () => {
 })
 
 test('http camelizes json response by default', () => {
-  return http(successUrl, {
+  return httpWithMock(successUrl, {
     method: 'POST',
-    __mock_response: {
+  }, {
       camelized_key: 'a camelized key'
-    },
-  }).then((res) => {
+    }).then((res) => {
     expect(res).toHaveProperty('camelizedKey')
   })
 })
 
-test('http does not camelizes json response if camelize passed as false', () => {
-  return http(successUrl, {
+test('http does not camelize json response if camelize passed as false', () => {
+  return httpWithMock(successUrl, {
     camelizeResponse: false,
-    __mock_response: {
+  }, {
       Capitalized_key: 'a weirdly cased key'
-    }
-  }).then((res) => {
+    }).then((res) => {
     expect(res).toHaveProperty('Capitalized_key')
   })
 })
@@ -303,8 +300,27 @@ test('http returns null when the status is 204 (no content)', () => {
     })
 })
 
+test('http returns null when json parsing fails by default', () => {
+  return httpWithMock(successUrl, {}, "123AZY")
+    .then((res) => {
+      expect(res).toBe(null)
+    })
+})
+
+test('http returns text of body when json parsing fails and parseJsonStrictly is `false`', () => {
+  return httpWithMock(successUrl, { parseJsonStrictly: false }, "123AZY")
+    .then((res) => {
+      expect(res).toBe('123AZY')
+    })
+})
+
 /* MOCK STUFF */
 
+async function httpWithMock(url, options, responseBody) {
+  const mockResponse = new MockResponse(url, options, responseBody)
+  return http(url, { ...options, __mock_response: mockResponse })
+}
+
 // Mock token elements
 const createTokenTag = (name, content) => {
   const tag = document.createElement('meta')