URQL GraphCache creates type error when there are no mutations

[matthew-petrie]

Issue workflow progress

• [x] 1. The issue provides a reproduction: https://github.com/matthew-petrie/graphql-code-generator-issue-sandbox-template
• [x] 2. A failing test has been provided (see linked PR)
• [x] 3. A local solution has been provided (see https://github.com/matthew-petrie/graphql-code-generator-issue-sandbox-template)
• [x] 4. A pull request is pending review

Describe the bug

The typescript-urql-graphcache plugin causes a typescript error in the generated type file for the type GraphCacheOptimisticUpdaters if the schema has no mutations:

To Reproduce Reproduction repo: https://github.com/matthew-petrie/graphql-code-generator-issue-sandbox-template

Steps to reproduce the behavior:

1. My GraphQL schema:

type Query {
    user(id: ID!): User!
}

type User {
    id: ID!
    username: String!
    email: String!
}

2. My GraphQL operations:

query user {
    user(id: 1) {
        id
        username
        email
    }
}

3. My codegen.yml config file:

schema: schema.graphql
documents: document.graphql
generates:
  types.ts:
    plugins:
      - typescript
      - typescript-operations
      - typescript-urql-graphcache

Expected behavior

For typescript-urql-graphcache to generate a types file with no Typescript errors. If there are no mutations GraphCacheOptimisticUpdaters should be output as:

export type GraphCacheOptimisticUpdaters = {};

Environment:

• OS: macOS Monterey 12.3 - M1 Pro chip
• @graphql-codegen/typescript-urql-graphcache: ^2.2.13
• typescript: ^4.7.2
• NodeJS: v16.13.1

[matthew-petrie]

Raised a PR to fix this bug: https://github.com/dotansimha/graphql-code-generator/pull/7911