Lint with eslint

Requires at least node v8.x

.travis.yml

@@ -16,7 +16,7 @@ go:
     - 1.10.x
 
 env:
-    - TRAVIS_NODE_VERSION="6" CC="gcc-5" CXX="g++-5"
+    - TRAVIS_NODE_VERSION="8" CC="gcc-5" CXX="g++-5"
 
 before_install:
     - nvm install $TRAVIS_NODE_VERSION
@@ -39,4 +39,5 @@ script:
     - go vet ./...
     - go test -v -race ./...
     - cd proxy
+    - npm run lint
     - npm test

proxy/.eslintrc.json

@@ -0,0 +1,8 @@
+{
+    "env": {
+        "browser": true,
+        "es6": true,
+        "node": true
+    },
+    "extends": "eslint:recommended"
+}

proxy/package.json

@@ -12,7 +12,8 @@
     "webext": "node make.js webext",
     "clean": "node make.js clean",
     "prepublish": "node make.js node",
-    "start": "node build/snowflake.js"
+    "start": "node build/snowflake.js",
+    "lint": "eslint . --ext .js"
   },
   "bin": {
     "snowflake": "build/snowflake.js"
@@ -20,6 +21,7 @@
   "author": "Serene Han",
   "license": "BSD-3-Clause",
   "devDependencies": {
+    "eslint": "^6.0.1",
     "jasmine": "2.5.2"
   },
   "dependencies": {