[relay-compiler 13] The root of subscription must be a simple selection

[radoslavkarlik]

Reporting issues with Relay

Given schema

type Subscription {
    changed: String!
}

And App.tsx

graphql`
  subscription App_Subscription {
      changed
  }
`;

I get this error: [ERROR] ✖︎ The root of subscription 'App_Subscription' must be a simple selection.

It seems like the subscription result needs to be an object. However, returning simple scalars worked in older versions. Is this a breaking change/intended way to use subscriptions?

[kassens]

This is an accidental regression. We need this for an internal purpose (I think logging the subscription name or something), but the validation shouldn't happen in OSS code. We'll move this to private extensions.

[alunyov]

This should be fixed with relay-compiler@main.

[artola]

@alunyov This issue was closed, but it remains for me. It is not working with newest v13 neither relay-compiler@master.
@radoslavk is it working for you?

[alunyov]

Hey @artola can you provide more details here? Are you seeing the same error message?

[artola]

@alunyov I confirm the same error reported above.

[ERROR] ✖︎ The root of subscription 'demo4Subscription' must be a simple selection.

  pages/demo4.js:2:22
    1 │ 
    2 │         subscription demo4Subscription($from: Int!) {
      │                      ^^^^^^^^^^^^^^^^^
    3 │           countdown(from: $from)

[ERROR] Compilation failed.

Same result for:

• @latest - 13.0.0
• @main - 0.0.0-main-35e0c2bd

This produces the error:

type Subscription {
  countdown(from: Int!): Int
}

graphql`
        subscription demo4Subscription($from: Int!) {
          countdown(from: $from)
        }
      `

While this works:

type Countdown {
  current: Int!
}

type Subscription {
  countdown(from: Int!): Countdown
}

graphql`
        subscription demo4Subscription($from: Int!) {
          countdown(from: $from) {
            current
          }
        }
      `

[alunyov]

Hmm, this is strange. Let me reopen this to double-check.

[alunyov]

@artola can you check with this version: 97a0e95

it should be available on NPM as relay-compiler@main

[artola]

@artola can you check with this version: 97a0e95

it should be available on NPM as relay-compiler@main

@alunyov IT WORKS!!! ... now it is possible to return some scalar as in the examples above. Thanks!