While emulating Hosting and Functions, requests to the home location don't trigger the corresponding Cloud Function

[REQUIRED] Environment info

Packages:

firebase-tools@7.7.0 (globally installed)
"firebase-functions": "^3.3.0",   // FROM functions/package.json

Node version: v10.16.2 VSCode 1.32.3

firebase-tools: v7.7.0

Platform: Windows 10

[REQUIRED] Test case

firebase.json

{
  "firestore": {
    "rules": "firestore.rules",
    "indexes": "firestore.indexes.json"
  },
  "functions": {
    "predeploy": [
      "npm --prefix \"$RESOURCE_DIR\" run lint"
    ],
    "ignore": [
      "functions/src/**"
    ]
  },
  "hosting": {
    "public": "public",
    "ignore": [
      "firebase.json",
      "**/.*",
      "**/node_modules/**"
    ],
    "rewrites": [
      {
        "source": "**",
        "function": "ssrLanding"
      }
    ]
  },
  "storage": {
    "rules": "storage.rules"
  }
}

With the firebase.json config above, I’m trying to rewrite routes to my home location (with or without trailing slash) to be handled by a cloud functions.

[REQUIRED] Steps to reproduce

Using the firebase.json above. Run firebase serve --only hosting,functions Or firebase emulators:start --only hosting,functions

PS C:\myProject> firebase serve --only hosting,functions
i  hosting: Serving hosting files from: public
+  hosting: Local server: http://localhost:5000
+  functions: Using node@10 from host.
+  functions: Emulator started at http://localhost:5001
i  functions: Watching "C:\myProject\functions" for Cloud Functions...
+  functions[ssrLanding]: http function initialized (http://localhost:5001/myProject/us-central1/ssrLanding).

Everything starts OK, as we can see from the log above.

[REQUIRED] Expected behavior

I would request http://localhost:5000 or http://localhost:5000/ (with or without trailing slash) and the function ssrLanding would handle the response.

Actually, with this configuration, any location should be handled by the function, right?

[REQUIRED] Actual behavior

When I request http://localhost:5000 or http://localhost:5000/ the server responds with the index.html file which is in my public folder.

When I request http://localhost:5000/whatever, the function is triggered and responds.

[samtstern]

@cbdeveloper thanks that’s good feedback! I’ll make sure your docs feedback bug gets to the right person and also link them to this explanation

[cbdeveloper]

Thanks! https://stackoverflow.com/questions/44925138/firebase-dynamic-hosting-rewrite-the-home-page https://stackoverflow.com/questions/53519531/how-to-change-firebase-homepage-destination/53520119#53520119

From these two SO questions and people’s comments on them, I think this might be causing a some confusion.

Priority order of Hosting responses

1. Reserved namespaces that begin with a /__/* path segment
2. Configured redirects
3. Exact-match static content
4. Configured rewrites
5. Custom 404 page
6. Default 404 page

From what you’ve said, I guess that the homepage '/' route defaults to index.html and therefore it’s categorized as a number 3 from the list above, which is higher than “Configured Rewrites” for the '/' homepage route.

But I think the examples in the DOCs and also from the default configuration that firebase-tools sets when you init a project as a single page app, might cause this confusion.

{
    "source": "**",
    "destination": "/index.html"
  }

I think it would be useful to add to the DOCs (under the direct requests to a cloud function section), some note about rewriting the homepage '/’ route to a cloud function. I guess it would be nice to mention a recommended workaround.

A recommended workaround would be to change the index.html name for something different, like app.html ? Is there any better option ?

I know that serving index.html for the home route is standard default for HTTP servers, but I think it’s worth mentioning it explicitly. Otherwise it’s easy to forget.

PS: I’ve also sent a feedback through the DOCs website.