Save source with HIE files

[fendor]

Closes #671

Only manual testing done, yet. Not sure how this can be tested, suggestions welcome!

[cocreature]

Thanks! I agree that the GetSourceFileSource rule seems unnecessary. As for tests, maybe we could just spin up ghcide to generate the file and read it afterwards in a test and see if it contains the source?

[fendor]

I think there is no real way of knowing the hie file location from outside ghcide. It looks to me like we would need unit-tests that can directly access inner rules to really test it.

[pepeiborra]

This seems like a very roundabout way of reading a file: String -> Text -> BS.
Why not use BS.readFile like GHC does?

https://gitlab.haskell.org/ghc/ghc/-/blob/master/compiler/GHC/Iface/Ext/Ast.hs#L284

[fendor]

Good point, thank you!

Side question, is there some invariant that this filepath exists in the filesystem? Do we need more exception handling here?

[pepeiborra]

Hmm, I think existing error handling will deal with this if the file does not exist.

[wz1000]

I think a better way to achieve this would be to save the file contents along with the parsed module, so that we can be sure that it is never out of sync.

This can be done along with the getFileContents rule in the parsed module definition.

[pepeiborra]

I think a better way to achieve this would be to save the file contents along with the parsed module, so that we can be sure that it is never out of sync.

This can be done along with the getFileContents rule in the parsed module definition.

The Shake graph already guarantees this property I think

[pepeiborra]

rebase needed