refactor: don't use default backend, to avoid unnecessary deps (#54)

BREAKING CHANGE to avoid pulling in `request`.

lib/client.js

@@ -1,9 +1,10 @@
 const Component = require('./loader')
-const Request = require('./backends/request')
 
 class Client {
   constructor (options) {
-    const backend = options.backend || new Request(options.config)
+    const backend = options.backend
+    if (!backend) throw new Error('expected "backend"')
+
     const root = new Component({ splits: [], backend, getNames: options.getNames })
     if (options.spec) root._addSpec(options.spec)
     return root

lib/client.test.js

@@ -1,6 +1,7 @@
 /* eslint-env mocha */
 const { expect } = require('chai')
 const nock = require('nock')
+const RequestBackend = require('./backends/request')
 
 const Client = require('./client')
 
@@ -16,8 +17,9 @@ describe('lib.client', () => {
             message: 'ta dah'
           })
 
+        const config = { url }
         const options = {
-          config: { url },
+          config,
           spec: {
             paths: {
               '/magic': {
@@ -26,7 +28,8 @@ describe('lib.client', () => {
                 }
               }
             }
-          }
+          },
+          backend: new RequestBackend(config)
         }
         const client = new Client(options)
         client.magic.get()
@@ -45,8 +48,9 @@ describe('lib.client', () => {
             message: 'fail!'
           })
 
+        const config = { url }
         const options = {
-          config: { url },
+          config,
           spec: {
             paths: {
               '/magic': {
@@ -55,7 +59,8 @@ describe('lib.client', () => {
                 }
               }
             }
-          }
+          },
+          backend: new RequestBackend(config)
         }
         const client = new Client(options)
         client.magic.get()
@@ -71,8 +76,9 @@ describe('lib.client', () => {
           .get('/magic')
           .replyWithError({ message: 'fail!' })
 
+        const config = { url }
         const options = {
-          config: { url },
+          config,
           spec: {
             paths: {
               '/magic': {
@@ -81,7 +87,8 @@ describe('lib.client', () => {
                 }
               }
             }
-          }
+          },
+          backend: new RequestBackend(config)
         }
         const client = new Client(options)
         client.magic.get()
@@ -90,6 +97,25 @@ describe('lib.client', () => {
             done()
           })
       })
+
+      it('throws on missing "backend"', done => {
+        const config = { url }
+        const options = {
+          config,
+          spec: {
+            paths: {
+              '/magic': {
+                get: {
+                  operationId: 'getMagic'
+                }
+              }
+            }
+          }
+        }
+
+        expect(() => new Client(options)).to.throw('backend')
+        done()
+      })
     })
   })
 })