Support graphql imports

[dobesv]

Feature request description

GraphQL is a popular technology, which uses files with the .graphql extension to define schemas and operations. In many environments, these files can import other files (including from packages) use a syntax like:

#import 'path/to/other.graphql`
#import './whatever.graphql`

The given path is passed directly to node's require mechanism.

Example parser implementation:

const requirePackageName = require('require-package-name');

const graphqlParser = (filePath, deps, rootDir) => {
  const foundDeps = [];
  const content = readFileSync(filePath, {encoding: 'utf8'});
  const lines = content.split(/\r\n|\r|\n/);
  for (const line of lines) {
    if (line[0] === '#' && line.slice(1).split(' ')[0] === 'import') {
      const importFileExpr = line.slice(1).split(' ')[1];
      if (importFileExpr) {
        // Need to support single and double quotes, so use JSON5
        const importFile = JSON5.parse(importFileExpr) as any;
        if (importFile && typeof importFile === 'string') {
          foundDeps.push(importFile);
        }
      }
    }
    // Imports must be in a comment block at the start of the file
    if (line.length !== 0 && line[0] !== '#') {
      break;
    }
  }
  return foundDeps.map(p => requirePackageName(p)).filter(Boolean);;
};

[rumpl]

I didn't know graphql can do that, is there a parser somewhere that we can use instead of splitting strings?

[dobesv]

I got the implementation from here:

https://github.com/apollographql/graphql-tag/blob/main/loader.js#L29

If you try to use that parser, it's going to give you JavaScript which you can then parse. I had attempted to go that route at first but the textual parsing seems more efficient and doesn't add a lot of dependencies.

[rumpl]

Fair enough, if apollo does it that way then no need for us to get fancy about it :)

[dobesv]

The code above doesn't quite work, though ... still working on it.

[dobesv]

Would you accept a PR for this feature? Or should I just keep this local to our project?

[rumpl]

Oh I would definitely accept a PR for this! :)

thanks