mark LanguageService.getSourceFile as internal and rename it

[vladima]

fixes #7581.
LanguageService.getSourceFile is a very confusing method - it returns one non-bound source file that is only useful for syntactic analysis. The only consumer of this method uses it to reliably determine if file is an external module.

[mhegazy]

this is a breaking change, i remeber other users used it..
// cc: @basarat.

[basarat]

Thanks for mentioning. Double thanks for renaming to indicate difference 🌹

//cc @blakeembrey @jbrantly

[jbrantly]

Thanks for the mention. ts-loader doesn't use this method so I think it's unaffected.

[mhegazy]

// cc: @mprobst

[vladima]

//cc: @adidahiya

[mprobst]

Thanks for the heads up. I don't think we use this method, we just use ts.createSourceFile, so we should be good.

[blakeembrey]

Ah, I do use it in ts-node 😦 Do you know if source maps generate properly with inline contents now, that's all I was using it for.

[vladima]

Will it work if you replace it with LanguageService.getProgram().getSourceFile?

[blakeembrey]

@vladima Yes, definitely. Don't worry about it, I'll look into fixing it at the source too some time.

[adidahiya]

👍 TSLint is not using ts.getSourceFile directly.

[DanielRosenwasser]

👍