add eslint

.eslintrc

@@ -0,0 +1,57 @@
+{
+    "parserOptions": {
+        "ecmaVersion": 6,
+        "sourceType": "module"
+    },
+    "env": {
+        "browser": true,
+        "node": true
+    },
+    "rules": {
+        "constructor-super": 2,
+        "no-class-assign": 2,
+        "no-compare-neg-zero": 2,
+        "no-cond-assign": 2,
+        "no-const-assign": 2,
+        "no-constant-condition": 2,
+        "no-control-regex": 2,
+        "no-debugger": 2,
+        "no-delete-var": 2,
+        "no-dupe-args": 2,
+        "no-dupe-class-members": 2,
+        "no-dupe-keys": 2,
+        "no-duplicate-case": 2,
+        "no-empty-character-class": 2,
+        "no-empty-pattern": 2,
+        "no-empty": 2,
+        "no-ex-assign": 2,
+        "no-extra-boolean-cast": 2,
+        "no-extra-semi": 2,
+        "no-fallthrough": 2,
+        "no-func-assign": 2,
+        "no-global-assign": 2,
+        "no-inner-declarations": 2,
+        "no-invalid-regexp": 2,
+        "no-irregular-whitespace": 2,
+        "no-mixed-spaces-and-tabs": 2,
+        "no-new-symbol": 2,
+        "no-obj-calls": 2,
+        "no-octal": 2,
+        "no-redeclare": 2,
+        "no-regex-spaces": 2,
+        "no-self-assign": 2,
+        "no-sparse-arrays": 2,
+        "no-this-before-super": 2,
+        "no-undef": 2,
+        "no-unexpected-multiline": 2,
+        "no-unsafe-finally": 2,
+        "no-unsafe-negation": 2,
+        "no-unused-labels": 2,
+        "no-unused-vars": 2,
+        "no-useless-escape": 2,
+        "require-yield": 2,
+        "semi": 2,
+        "use-isnan": 2,
+        "valid-typeof": 2
+    }
+}

build/build.js

@@ -1,5 +1,6 @@
 const rollup = require("rollup");
 const buble = require("rollup-plugin-buble");
+const eslint = require("rollup-plugin-eslint");
 const uglify = require("uglify-js");
 const gzipSize = require("gzip-size");
 const fs = require("fs");
@@ -24,6 +25,7 @@ async function build() {
   const bundle = await rollup.rollup({
     input: path.join(cwd, "/src/index.js"),
     plugins: [
+      eslint(),
       buble()
     ]
   });

package.json

@@ -41,6 +41,7 @@
     "phantomjs-prebuilt": "^2.1.16",
     "rollup": "^0.58.1",
     "rollup-plugin-buble": "^0.19.2",
+    "rollup-plugin-eslint": "^4.0.0",
     "uglify-js": "^3.3.22"
   }
 }