add eslint

.eslintrc

@@ -0,0 +1,49 @@
+{
+  "env": {
+    "node": true
+  },
+  "extends": [
+    "eslint:recommended"
+  ],
+  "globals": {
+    "Promise": true
+  },
+  "rules": {
+    "semi": [
+      2,
+      "never"
+    ],
+    "no-cond-assign": [
+      2,
+      "except-parens"
+    ],
+    "no-unused-expressions": 2,
+    "indent": [
+      2,
+      2,
+      {
+        "SwitchCase": 1
+      }
+    ],
+    "comma-style": [
+      2,
+      "first"
+    ],
+    "max-len": [
+      2,
+      {
+        "code": 100,
+        "ignoreComments": true
+      }
+    ],
+    "new-cap": 2,
+    "strict": 0,
+    "no-trailing-spaces": 2,
+    "no-undef": 2,
+    "no-unused-vars": 2,
+    "quotes": [
+      2,
+      "single"
+    ]
+  }
+}

package.json

@@ -4,6 +4,7 @@
   "description": "PostCSS gulp plugin",
   "main": "index.js",
   "scripts": {
+    "pretest": "eslint index.js",
     "test": "mocha test.js"
   },
   "repository": {
@@ -29,10 +30,11 @@
     "vinyl-sourcemaps-apply": "^0.2.1"
   },
   "devDependencies": {
-    "gulp-sourcemaps": "^1.11.0",
+    "eslint": "^3.19.0",
+    "gulp-sourcemaps": "^2.6.0",
     "mocha": "^3.2.0",
-    "proxyquire": "^1.7.4",
-    "sinon": "^1.17.3"
+    "proxyquire": "^1.7.11",
+    "sinon": "^2.1.0"
   },
   "files": []
 }

test.js

@@ -366,7 +366,7 @@ describe('PostCSS Guidelines', function () {
       }
     }))
     stream.on('data', function () {
-      assert.deepEqual(postcssLoadConfigStub.getCall(0).args[1], __dirname + '/relative/path')
+      assert.deepEqual(postcssLoadConfigStub.getCall(0).args[1], path.join(__dirname, 'relative/path'))
       cb()
     })
     stream.end(new gutil.File({