add dependencies: yarn, eslint

.eslintrc.json

@@ -0,0 +1,61 @@
+{
+    "env": {
+        "browser": true,
+        "es2020": true
+    },
+    "parserOptions": {
+        "ecmaVersion": 11,
+        "sourceType": "module"
+    },
+    "rules": {
+        "semi": "off",
+        "brace-style": "off",
+        "object-curly-spacing": [
+            "error",
+            "always"
+        ],
+        "keyword-spacing": "off",
+        "padded-blocks": [
+            "error",
+            "never"
+        ],
+        "comma-dangle": [
+            "error",
+            "always-multiline"
+        ],
+        "space-before-blocks": "error",
+        "quotes": [
+            "error",
+            "single"
+        ],
+        "no-trailing-spaces": "error",
+        "eol-last": [
+            "error",
+            "always"
+        ],
+        "comma-spacing": "error",
+        "space-infix-ops": [
+            "error",
+            {
+                "int32Hint": false
+            }
+        ],
+        "no-multiple-empty-lines": [
+            "error",
+            {
+                "max": 1
+            }
+        ],
+        "key-spacing": [
+            "error",
+            {
+                "beforeColon": false,
+                "afterColon": true
+            }
+        ],
+        "semi-spacing": "error"
+    },
+    "ignorePatterns": [
+        "node_modules/**/*"
+    ]
+}

package.json

@@ -5,7 +5,8 @@
   "main": "index.js",
   "scripts": {
     "start": "nodemon index.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "lint": "eslint '**.*.js'"
   },
   "repository": {
     "type": "git",
@@ -36,6 +37,10 @@
     "passport-accesstoken": "^0.1.0",
     "router": "^1.3.5",
     "sequelize": "^4.44.4",
-    "swagger-jsdoc": "^4.0.0"
+    "swagger-jsdoc": "^4.0.0",
+    "yarn": "^1.22.4"
+  },
+  "devDependencies": {
+    "eslint": "^7.7.0"
   }
-}
+}