Performance optimizations: caching

[benjie]

Is your feature request related to a problem? Please describe.

GraphQL Codegen is amazingly powerful, but performance can be lacklustre at times. This issue is to open a conversation about what could be done to improve performance.

Describe the solution you'd like

There are a number of optimizations that could be put in place when ran in watch mode; I'm not sure which of these are already implemented?

• Files that have been parsed can be cached, and only re-parsed when the file watcher indicates they have changed
• Detected GraphQL documents in a TypeScript file can be cached, and logic put in place such that when a file changes if the GraphQL within it has not changed then there's no action necessary for that file
• Parsing of extracted GraphQL documents can be cached
• Parsing of the GraphQL schema can be cached
• Validation can be cached
• Type generation itself could be cached so that only types related to the changed document(s) need to be regenerated
• A comparison could be performed on the output versus the previous output so that files are only written if doing so would result in a concrete change, reducing overhead for TypeScript

Ultimately, it would be wonderful if adding a field to a GraphQL query in a large codebase could result in the generated code being output in under one second (ideally faster).

Describe alternatives you've considered

No response

Is your feature request related to a problem? Please describe.

No response