Firebase config overwrites unrelated keys

[ralphsmith80]

Do you want to request a feature or report a bug?
bug

What is the current behavior?
Output production on hosting key options

If the current behavior is a bug, please provide the steps to reproduce.
With an existing firebase.json file:
npm run serve -- --server config --dest .

What is the expected behavior?
The file is merged only overriding the hosting key. A deep merge of the hosting key might be even better, but I don't know that it's really needed.

Merged firebase.json:

{
  "database": {
    "rules": "database.rules.json"
  },
  "hosting": {
    "public": "build",
    "rewrites": [
      {
        "source": "**",
        "destination": "/index.html"
      }
    ],
    "headers": [
      {
        "source": "**",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "public, max-age=3600, no-cache"
          },
          {
            "key": "Access-Control-Allow-Origin",
            "value": "*"
          },
          {
            "key": "Access-Control-Max-Age",
            "value": "600"
          }
        ]
      },
      {
        "source": "/sw.js",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "private, no-cache"
          }
        ]
      },
      {
        "source": "**/*.chunk.*.js",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "public, max-age=31536000"
          }
        ]
      },
      {
        "source": "/",
        "headers": [
          {
            "key": "Link",
            "value":
              "</bundle.6acb8.js>; rel=preload; as=script, </style.ba975.css>; rel=preload; as=style, </route-home.chunk.8111b.js>; rel=preload;as=script"
          }
        ]
      }
    ]
  }
}

If this is a feature request, what is motivation or use case for changing the behavior?
When using CI/CD pipelines like Gitlab pipelines this config is going to change when the pipeline runs and should therefore be an automatable. In my case I also have a top level database key that I don't want overridden.

Please mention other relevant information.

• node version
  8.4.0
• npm version
  5.3.0
• Operating system
  mac sierra 10.12.6

[lukeed]

So you're saying that we're overwriting the entire firebase.json file with our own contents, thus deleting whatever was there previously?

[ralphsmith80]

@lukeed that's correct. Notice in my expected config file I have a top level database key which is used for defining database rules. In my case I'm just pointing to another file so I can separate that out, but the inline content would look something like:

{
  "rules": {
    "users": {
      "$uid": {
        ".read": "auth != null && auth.uid == $uid",
        ".write": "auth != null && auth.uid == $uid"
      }
    }
  }
}

When I run npm run serve -- --server config --dest . to generate the config it writes the following to firebase.json.

{
   "public":"build",
   "rewrites":[
      {
         "source":"**",
         "destination":"/index.html"
      }
   ],
   "headers":[
      {
         "source":"**",
         "headers":[
            {
               "key":"Cache-Control",
               "value":"public, max-age=3600, no-cache"
            },
            {
               "key":"Access-Control-Allow-Origin",
               "value":"*"
            },
            {
               "key":"Access-Control-Max-Age",
               "value":"600"
            }
         ]
      },
      {
         "source":"/sw.js",
         "headers":[
            {
               "key":"Cache-Control",
               "value":"private, no-cache"
            }
         ]
      },
      {
         "source":"**/*.chunk.*.js",
         "headers":[
            {
               "key":"Cache-Control",
               "value":"public, max-age=31536000"
            }
         ]
      },
      {
         "source":"/",
         "headers":[
            {
               "key":"Link",
               "value":"</bundle.6acb8.js>; rel=preload; as=script, </style.ba975.css>; rel=preload; as=style, </route-home.chunk.8111b.js>; rel=preload;as=script"
            }
         ]
      }
   ]
}

Without looking at the code it could probably be fixed by reading the JSON contents if it exists and then writing out using a merge on the "hosting" key.

e.g.
pseudocode

firebaseConfig = readJSON('firebase.json`) || {} 
writeJSON(
  JSON.stringify(
    Object.assign({}, firebaseConfig, {'hosting': preactFirebaseConfig})
  )
)

[lukeed]

Got it, thanks! Was just double-checking.

[silverlight513]

I'll take a look into this in a couple hours after work