add lint-staged

client/package.json

@@ -92,9 +92,11 @@
     "file-loader": "^6.0.0",
     "html-webpack-inline-source-plugin": "^1.0.0-beta.2",
     "html-webpack-plugin": "^4.0.0",
+    "husky": "^4.2.5",
     "jest": "^25.2.7",
     "jest-puppeteer": "^4.4.0",
     "json-loader": "^0.5.7",
+    "lint-staged": "^10.2.4",
     "mini-css-extract-plugin": "^0.9.0",
     "optimize-css-assets-webpack-plugin": "^5.0.3",
     "puppeteer": "^2.1.1",
@@ -147,5 +149,13 @@
         ]
       }
     }
+  },
+  "husky": {
+    "hooks": {
+      "pre-commit": "lint-staged"
+    }
+  },
+  "lint-staged": {
+    "*.js": "eslint --cache --fix"
   }
 }