fix(spawn): use cross-spawn for spawn compatibility

(cherry picked from commit 9be84e4)
originally by [@NogsMPLS](https://github.com/NogsMPLS) in #3 as
mentioned in #2

closes #2

package.json

@@ -39,6 +39,7 @@
     "chai": "3.3.0",
     "codecov.io": "0.1.6",
     "commitizen": "1.0.5",
+    "cross-spawn": "2.0.0",
     "cz-conventional-changelog": "1.1.2",
     "eslint": "1.5.1",
     "eslint-config-kentcdodds": "4.0.1",

src/index.js

@@ -1,4 +1,4 @@
-import {spawn} from 'child_process';
+import {spawn} from 'cross-spawn';
 import getPathVar from 'add-to-path/dist/get-path-var';
 export default crossEnv;
 

src/index.test.js

@@ -7,7 +7,7 @@ chai.use(sinonChai);
 
 const {expect} = chai;
 const proxied = {
-  child_process: { // eslint-disable-line camelcase
+  'cross-spawn': {
     spawn: sinon.spy(() => 'spawn-returned')
   }
 };
@@ -17,7 +17,7 @@ const crossEnv = proxyquire('./index', proxied);
 describe(`cross-env`, () => {
 
   beforeEach(() => {
-    proxied.child_process.spawn.reset();
+    proxied['cross-spawn'].spawn.reset();
   });
 
   it(`should set environment variables and run the remaining command`, () => {
@@ -30,7 +30,7 @@ describe(`cross-env`, () => {
 
   it(`should do nothing given no command`, () => {
     crossEnv([]);
-    expect(proxied.child_process.spawn).to.have.not.been.called;
+    expect(proxied['cross-spawn'].spawn).to.have.not.been.called;
   });
 
   function testEnvSetting(...envSettings) {
@@ -42,8 +42,8 @@ describe(`cross-env`, () => {
     });
 
     expect(ret, 'returns what spawn returns').to.equal('spawn-returned');
-    expect(proxied.child_process.spawn).to.have.been.calledOnce;
-    expect(proxied.child_process.spawn).to.have.been.calledWith(
+    expect(proxied['cross-spawn'].spawn).to.have.been.calledOnce;
+    expect(proxied['cross-spawn'].spawn).to.have.been.calledWith(
       'echo', ['hello world'], {stdio: 'inherit', env}
     );
   }