Use eslint

.eslintignore

@@ -0,0 +1,7 @@
+# We can probably lint these later but not important at this point
+src/vendor
+src/vendor_deprecated
+# estraverse stumbles on XJSSpreadAttribute so just ignore tests for now
+src/**/__tests__/**
+# This should be enabled but that folder has too much in it that doesn't belong
+src/test

package.json

@@ -38,6 +38,7 @@
     "envify": "^3.0.0",
     "es3ify": "~0.1.2",
     "es5-shim": "^4.0.0",
+    "eslint": "0.11.0-alpha.0",
     "grunt": "~0.4.2",
     "grunt-cli": "~0.1.9",
     "grunt-compare-size": "~0.4.0",
@@ -70,7 +71,8 @@
   },
   "scripts": {
     "test": "jest",
-    "jest": "jest"
+    "jest": "jest",
+    "lint": "eslint src"
   },
   "jest": {
     "rootDir": "",

src/.eslintrc

@@ -0,0 +1,52 @@
+---
+settings:
+  jsx: true
+  ecmascript: 6
+
+env:
+  browser: true
+  node: true
+
+globals:
+  __DEV__: true
+
+rules:
+  # ERRORS
+  brace-style: 2
+  space-after-keywords: 2
+  strict: 2
+  # We actually have a transform to support this and we fix this for bundled
+  # releases but not for the npm package, so enforce it strictly
+  no-comma-dangle: 2
+  # Make this a warning for now. We do this in a few places so we might need to
+  # disable
+  no-unused-expressions: 2
+  block-scoped-var: 2
+  eol-last: 2
+  dot-notation: 2
+  consistent-return: 2
+
+  # WARNINGS
+  quotes: [1, 'single']
+  # This is the only one that's hard to track since we don't lint just changes.
+  max-len: [1, 80]
+
+  # WISHLIST. One day...
+  # We'll need a custom version of this that does a subset of the whole rule.
+  # Otherwise this is just too noisy.
+  # valid-jsdoc: 1
+
+  # DISABLED. These aren't compatible with our style
+  # We use this for private/internal variables
+  no-underscore-dangle: 0
+  # We pass constructors around / access them from members
+  new-cap: 0
+  # We do this a lot.
+  no-use-before-define: 0
+  # We should have this enabled but https://github.com/eslint/eslint/issues/1542
+  no-unused-vars: 0
+  # We do this in a few places to align values
+  key-spacing: 0
+
+  # DISABLED. These currently cause errors when running.
+  no-multi-spaces: 0