Add Program.isSourceFileDefaultLibrary to public API

[timocov]

Search Terms

API, Program

Suggestion

Is there a chance to add isSourceFileDefaultLibrary to Programs API?

For now, it is marked as @internal and this method is removed from declaration file https://github.com/Microsoft/TypeScript/blob/70975cd08f48497f3ae6538ff69bf50cac23706b/src/compiler/types.ts#L2777

Use Cases

I working on https://github.com/timocov/dts-bundle-generator and there I need to know what files are default lib files. I need to know it to skip these files from preparing. It seems that is the right way to detect it, but it is not public.

If there is another way to check that some file is default lib file - please let me know.

Related to timocov/dts-bundle-generator#39.

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript / JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. new expression-level syntax)

[ajafff]

I had a similar requirement when I wanted to exclude all external files from linting.
There is a lot more that needs to be considered though:

• other library files referenced by the default lib file
• @types/<package> implicitly added
• tslib that somehow is added to the Program if you symlink multiple projects' source folders
• files from external packages

This is my implementation that handles all of these cases: https://github.com/fimbullinter/wotan/blob/a3cfe28ef9162dacf451c839efa2f26be30d1ce1/packages/wotan/src/runner.ts#L196-L216

[timocov]

@ajafff In my case, I need to know only if a file is default lib file, but anyway thanks for the additional information!

[ajafff]

In that case you could simply compare to ts.getDefaultLibFilePath(program.getCompilerOptions())

[timocov]

It seems that ts.getDefaultLibFilePath(program.getCompilerOptions()) returns only one default lib file - lib.d.ts, but I need to check every lib file (e.g. lib.es2015.d.ts or lib.es2017.d.ts).

[ajafff]

isSourceFileDefaultLibrary is probably not what you are looking for. It only handles the default library file and those declared in compilerOptions.lib.

You might want to do the path comparison yourself:

// may need some special handling to normalize slashes and file casing
path.dirname(sourceFile.fileName) === path.dirname(ts.getDefaultLibFilePath(program.getCompilerOptions()));

[timocov]

I guess there is some misunderstanding - I need to filter all lib files (I thought it called "default lib files"). Program.isSourceFileDefaultLibrary does exactly what I need and I believe any other solution is not entirely correct because only compiler knows what is default library file and what is not.

Of course, we can create one more solution (with checking the path of the file or something else), but compiler knows it already, so why I need to do its work? 🙂

[timocov]

You might want to do the path comparison yourself:

But in this case, we'll filter typescript.d.ts file and this is not what I actually want.

is probably not what you are looking for

Why not? As far as I understand it checks that file is lib.xxx.d.ts file, doesn't it?

https://github.com/Microsoft/TypeScript/blob/bd97e12f760773aac87d62159fa26ea1474a2337/src/compiler/program.ts#L1291-L1309

[mhegazy]

A PR would be appreciated.