Error: HTTP Error 400, The Request has errors. Firebase Firestore Cloud Functions

I had this problem as well. In my case it was because my trigger path had a trailing slash in the document path.

So changing:

functions.firestore
  .document('some_path/{pushId}/')

To:

functions.firestore
  .document('some_path/{pushId}')

Fixed it it for me. It seems like this is caused by a variety of issues and the firebase cli does not do a good job at explaining the reasons why.

For me none of the answers helped me. In the end I got a list of steps (from Google) to pinpoint the problem. If you run:

firebase --debug --only functions deploy

it will give a more detailed error-message, what was in my case:

HTTP RESPONSE BODY <?xml version='1.0' encoding='UTF-8'?><Error><Code>EntityTooLarge</Code><Message>Your proposed upload is larger than the maximum object size specified in your Policy Document.</Message><Details>Content-length exceeds upper bound on range</Details></Error>

Okej this is what you need to look at.

since you have

exports.yourFunctionName = functions.firestore.document

the thing you need to look at is the .document

Your path MUST point to a document and not to a collection.

so this will not work :

/level1/{level1Id}/level2 <- it points to a collection

this will work :

/level1/{level1Id}/level2/{level2Id}

cloud function will look for when a document has an action

Hope this will help anybody

The problem is that you only reference a collection and not a document like:

exports.myFunctionName = functions.firestore
      .document('users').onWrite((event) => {
        // ... Your code here
      });

You need to reference the document like:

exports.myFunctionName = functions.firestore
  .document('users/marie').onWrite((event) => {
    // ... Your code here
  });

You can also use a wildcard like:

exports.myFunctionName = functions.firestore
  .document('users/{userId}').onWrite((event) => {
    // ... Your code here
  });

It's described in here: https://firebase.google.com/docs/functions/firestore-events

Hope I could help

The issue was probably caused by the length of the function name.

So, if the name is:

myFunctionsFromWorksWithCustumersTiggersTests

change for a shorter name, like:

WorkWithCustumers

I hope I helped.

I had the same error when trying to publish a function listening to a Cloud pub/sub, that began with numerical characters.

exports.nightly_pruning = functions.pubsub.topic('24hr-tick').onPublish((event) => { 
    ... 
});

Fixed it by simply changing the name:

exports.nightly_pruning = functions.pubsub.topic('nightly-tick').onPublish((event) => { 
    ... 
});

(Thanks to Nikolai Hegelstad above. I don't have the reputation to comment.)

I was also getting the same error until i changed my function name from

create_template_

to

create_new_template

It might be that '_'(underscore) at the end of function name resulted in this error.

I experienced this because of the underscore at the start of the exports function name. You can test it yourself by trying this:

exports._someLongNameWithUnderscore= functions.auth.user().onCreate(user => {
  return true;
});

exports.someLongNameWithoutUnderscore= functions.auth.user().onCreate(user => {
  return true;
});

exports.shortName= functions.auth.user().onCreate(user => {
  return true;
});

The one with the underscore at the start or end will fail with HTTP:400 and the others will deploy.

This can also happen if you're using the wrong Node version. I just experienced that after setting my node version to 8.x while working on functions. Switched back to v10.x and the issue disappeared.

If anybody is still experiencing this, in my case solution was running npm install -g firebase-tools to update cli, and adding

"engines": {
  "node": "8"
}

to package.json

My issue with the same error message was that Cloud Functions' pubsub doesn't seem to support topics with names beginning with numeral characters.

Just wanted to point out as well that the linter will reject line breaks on listener declaration, ie:

exporst.myFunc = functions.firestore
.document('collection/{uid}')
.onEvent(...)

which the linter doesnt help much and is not covered in documentation (as usual)

Check your database region. The function should be deployed in the same region of the database. This worked for me