Processor `@graphql-eslint/graphql` might fail to process due to GraphQL comments.

Intro Not sure if this is really graphql-eslint or graphql-tag-pluck issue, but I’ve found a clear reproducible case using this repository, so I thought, I’ll report it here. Also, I’ve made a repository where the issue is reproducible.

Describe the bug

It seems that if processor: '@graphql-eslint/graphql' option is used together with .graphql or .gql files and if those files contain comments, processor might fail to process the file.

E.g.

• This one is processed without any issues:

  fragment UserFields on User {
    id
    name
  }
  

• This one is processed as well without any issues:

  # Just any comment without any other file mentions
  fragment UserFields on User {
    id
    name
  }
  

• This file fails:

  # Lets mention another file, e.g.: User1.fragment.gql in this comment
  fragment UserFields on User {
    id
    name
  }
  

To Reproduce

Use this repository: https://github.com/lukaskl/graphql-eslint-parse-issue

git clone [e-mail]:lukaskl/graphql-eslint-parse-issue.git
cd graphql-eslint-parse-issue
yarn install --frozen-lockfile
yarn eslint .

✅ Expected result

The output should be something like this:

➜  graphql-eslint-parse-issue yarn eslint .
yarn run v1.15.2

***/src/User0.fragment.gql
  3:4  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

***/src/User1.fragment.gql
  4:4  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

***/src/User2.fragment.gql
  4:4  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

✖ 3 problems (0 errors, 3 warnings)

🔴 Actual result

➜  graphql-eslint-parse-issue yarn eslint .
yarn run v1.15.2
$ ***/node_modules/.bin/eslint .
[graphql-eslint/processor]: Unable to process file "***/src/User2.fragment.gql":  SyntaxError: Unexpected token (1:0)
    at Object._raise (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:776:17)
    at Object.raiseWithData (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:769:17)
    at Object.raise (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:737:17)
    at Object.unexpected (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:9253:16)
    at Object.parseExprAtom (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:10743:20)
    at Object.parseExprAtom (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:4996:20)
    at Object.parseExprSubscripts (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:10318:23)
    at Object.parseUpdate (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:10298:21)
    at Object.parseMaybeUnary (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:10276:23)
    at Object.parseExprOps (***/node_modules/@graphql-tools/graphql-tag-pluck/node_modules/@babel/parser/lib/index.js:10141:23) {
  loc: Position { line: 1, column: 0 },
  pos: 0
}

***/src/User0.fragment.gql
  3:4  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

***/src/User1.fragment.gql
  4:4  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

***/src/User2.fragment.gql
  4:4  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

✖ 3 problems (0 errors, 3 warnings)

Environment:

• OS: macOS Catalina
• @graphql-eslint/eslint-plugin@: 0.9.1
• NodeJS: v14.13.1

Additional context

[B2o5T]

If you have documents in both javascript files and .graphql files, your config need to be looks like this

module.exports = {
  env: {
    es6: true
  },
  overrides: [
    {
      files: ['*.js'],
      processor: '@graphql-eslint/graphql',
    },
    {
      files: ['*.graphql', '*.gql'],
      parser: '@graphql-eslint/eslint-plugin',
      parserOptions: {
        schema: './**/schema.gql',
      },
      plugins: ['@graphql-eslint'],
      rules: {
        '@graphql-eslint/no-deprecated': 'warn',
      },
    },
  ],
}

and try to add this fragment to javascript file

const someFragment = gql`
  # Just some another comment
  fragment SomeUserFields on User {
    id
    name
  }
`

We’ll give me this output

/Users/dimitri/graphql-eslint-parse-issue/src/User0.fragment.gql
  3:4  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

/Users/dimitri/graphql-eslint-parse-issue/src/User1.fragment.gql
  4:4  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

/Users/dimitri/graphql-eslint-parse-issue/src/User2.fragment.gql
  4:4  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

/Users/dimitri/graphql-eslint-parse-issue/src/index.js
  4:6  warning  This field is marked as deprecated in your GraphQL schema (reason: Use `firstName` instead.)  @graphql-eslint/no-deprecated

✖ 4 problems (0 errors, 4 warnings)

[lukaskl]

I can confirm that, moving processor: '@graphql-eslint/graphql', inside of the overrides works well 👍 Thank you!

And if there is no wish to do anything here more (e.g. documentation or examples update), then we can simply close this ticket.