Improve code quality and write tests

node_modules/codecov/test/git.test.js

@@ -0,0 +1,20 @@
+var git = require('../lib/git')
+var execSync = require('child_process').execSync
+
+describe('Git', function() {
+  it('can get the branch', function() {
+    expect(git.branch()).toEqual(
+      execSync('git rev-parse --abbrev-ref HEAD || hg branch')
+        .toString()
+        .trim()
+    )
+  })
+
+  it('can get the head', function() {
+    expect(git.head()).toEqual(
+      execSync("git log -1 --pretty=%H || hg id -i --debug | tr -d '+'")
+        .toString()
+        .trim()
+    )
+  })
+})