Export `Parser` class?

[dotansimha]

At the moment, the Parser class isn't exported at all (https://github.com/graphql/graphql-js/blob/master/src/language/parser.js#L165) which limits the ability to extend or use it as-is.

Is there a reason for that?

I would like to extend and add functionality to it, but it seems like it's not possible :(

@IvanGoncharov

[IvanGoncharov]

@dotansimha Exported in #2744 note that we plan so major changes to parser implementation as part of merging GraphiQL into graphql-js plus this class can be changed due to reflect spec changes.
So you should treat this API as exported but it still treated as internal API in all other aspects including versioning.
It also accessible only with explicit import:

import { Parser } from 'graphql/language/parser`

Also, can you please share what features is missing in our current parser so we can consider adding it in the future?

[dotansimha]

@IvanGoncharov thanks!

I wanted to fix a parsing issue related to comments/descriptions.
There is commentsDescriptions in print method, in order to print it correctly, but in terms of parsing, v15 of graphql-js will hide internally all comments that were defined with #.
This was needed for graphql-codegen - we wanted to allow developers to load their schema from SDL that contains #, and convert the # into """ comments while parsing (and not while printing), in order to have access to those later, while traveling the AST tree with visit.
Since Parser wasn't available, we needed to wrap it with a custom parse method here: ardatan/graphql-tools#1900 , that convert # to """ prior to calling the original parse.
Ideally, we would implement an extended version of Parser that does that automatically (instead of parsing it twice).

[IvanGoncharov]

@dotansimha Thanks for the detailed explanation 👍
Note: we will remove support for # as descriptions in v16.

[dotansimha]

Yeah I know, that's the reason we wanted to support it in graphql-tools. To allow developers who still have # comments to upgrade to v16 of graphql and still use the tools without breaking changes :)