buggy code highlighting

frontend/package.json

@@ -9,6 +9,7 @@
     "@types/autoprefixer": "^9.4.0",
     "@types/enzyme": "^3.9.1",
     "@types/enzyme-adapter-react-16": "^1.0.5",
+    "@types/highlight.js": "^9.12.3",
     "@types/jest": "^24.0.11",
     "@types/node-sass": "^4.11.0",
     "@types/parcel-bundler": "^1.12.0",
@@ -30,6 +31,7 @@
   "dependencies": {
     "@blueprintjs/core": "^3.15.1",
     "@blueprintjs/icons": "^3.8.0",
+    "highlight.js": "^9.15.6",
     "http2": "^3.3.7",
     "rea": "0.0.1",
     "react": "^16.8.6",