add lint-staged

.huskyrc

@@ -0,0 +1,5 @@
+{
+  "hooks": {
+    "pre-commit": "npm run check-types && lint-staged"
+  }
+}

.lintstagedrc

@@ -0,0 +1,9 @@
+{
+  "*.+(js|ts|tsx)": [
+    "eslint"
+  ],
+  "*.+(js|json|ts|tsx)": [
+    "prettier --write",
+    "git add"
+  ]
+}

package.json

@@ -21,6 +21,8 @@
     "@typescript-eslint/parser": "^2.7.0",
     "eslint": "^6.6.0",
     "eslint-config-prettier": "^6.5.0",
+    "husky": "^3.0.9",
+    "lint-staged": "^9.4.2",
     "prettier": "^1.19.1",
     "typescript": "^3.7.2"
   }