misc: add more eslint rules

.eslintrc.json

@@ -1,26 +1,27 @@
 {
-    "env": {
-        "es6": true,
-        "node": true
-    },
-    "extends": "eslint:recommended",
-    "rules": {
-        "indent": [
-            "error",
-            4
-        ],
-        "linebreak-style": [
-            "error",
-            "unix"
-        ],
-        "no-console": "off",
-        "quotes": [
-            "error",
-            "single"
-        ],
-        "semi": [
-            "error",
-            "always"
-        ]
-    }
-}
+  "env": {
+    "es6":  true,
+    "node": true
+  },
+  "extends": "eslint:recommended",
+  "parserOptions": {
+    "ecmaVersion": 7,
+    "ecmaFeatures": { "experimentalObjectRestSpread": true }
+  },
+  "rules": {
+    "linebreak-style":    [ "error", "unix" ],
+    "no-console":           "off",
+    "no-trailing-spaces":   "error",
+    "no-var":               "error",
+    "prefer-const":         "error",
+    "quotes":             [ "error", "single" ],
+    "semi":               [ "error", "always" ],
+    "indent": [ "error", 2, {
+      "ArrayExpression":       "first",
+      "ObjectExpression":      "first",
+      "FunctionExpression":  { "parameters": "first" },
+      "FunctionDeclaration": { "parameters": "first" },
+      "CallExpression":      { "arguments":  "first" }
+    }]
+  }
+}