Added utility to handle various body formats (#14)

* added utility to handle various body formats

* fixed typos

package.json

@@ -33,6 +33,7 @@
     "babel-preset-latest": "^6.16.0",
     "babel-register": "^6.18.0",
     "chai": "^3.5.0",
+    "form-data": "^2.1.2",
     "mocha": "^3.2.0",
     "standard": "^8.6.0"
   },
@@ -43,7 +44,8 @@
     "globals": [
       "describe",
       "it",
-      "expect"
+      "expect",
+      "FormData"
     ]
   }
 }

src/utilities/body.js

@@ -0,0 +1,14 @@
+export default (body) => {
+  // Handle empty case
+  if (!body) return null
+  // Handle FormData
+  if (body instanceof FormData) return body
+  try {
+    // Handle already stringified JSON
+    JSON.parse(body)
+    return body
+  } catch (err) {
+    // Handle plain object
+    return JSON.stringify(body)
+  }
+}

src/utilities/normalize.js

@@ -1,3 +1,5 @@
+import processBody from './body'
+
 /*
   Take in raw query string and
   return a fetch api compatible object
@@ -45,7 +47,7 @@ export default (strings, vars) => {
     url,
     options: {
       method: method || 'GET',
-      body: body ? JSON.stringify(body) : null,
+      body: processBody(body),
       ...options
     }
   }

tests/setup.js

@@ -1,4 +1,6 @@
 import 'babel-polyfill'
+import FormData from 'form-data'
 import { expect } from 'chai'
 
 global.expect = expect
+global.FormData = FormData

tests/unit/body.js

@@ -0,0 +1,32 @@
+import processBody from '../../src/utilities/body'
+
+describe('processBody', () => {
+  it('returns null when no value is passed', () => {
+    const body = processBody()
+    expect(body).to.equal(null)
+  })
+
+  it('returns null when empty string is passed', () => {
+    const body = processBody('')
+    expect(body).to.equal(null)
+  })
+
+  it('returns input when FormData is passed', () => {
+    const fd = new FormData()
+    const body = processBody(fd)
+    expect(body).to.equal(fd)
+  })
+
+  it('returns input when stringified data is passed', () => {
+    const data = JSON.stringify({value: 'test'})
+    const body = processBody(data)
+    expect(body).to.equal(data)
+  })
+
+  it('returns stringified data when object is passed', () => {
+    const rawData = {value: 'test'}
+    const data = JSON.stringify(rawData)
+    const body = processBody(rawData)
+    expect(body).to.equal(data)
+  })
+})