I want a public API for TypeScript language service plugin ( this is related to #254 (comment) ).

API proposal

Signature

parseForESLintFromSourceFile(
    sourceFile: ts.sourceFile,
    options?: ParserOptions | null,
): ParseForESLintResult

Expected behavior

This new function should works almost the same as parseForESLint. However, the following points are different:

• result.ast should be converted by @typescript-eslint/typescript-estree/src/ast-converter directly.
• result.services.program should be undefined ( I want to skip to call createProgram)

Motivation

I develop a TypeScript language service plugin to integrate tsserver and ESLint, https://github.com/Quramy/typescript-eslint-language-service.

In tsserver, ts.LanguageService does:

• tokenize source text and create an AST node. And the parsing is so fast because of ts.IncrementalParser.
• provide ts.Program ( So ts-estree don't need call createProgram )

Of course, I can provide a language service plugin using only public @typescript-eslint/parser APIs. But they accept only string text. So source code's text would be tokenized twice if using these public APIs. It's so silly.

Now I use some internal APIs ( see https://github.com/Quramy/typescript-eslint-language-service/blob/v1.2.3/src/ast-converter.ts#L187 ) for the above performance reason. But depending on them is too fragile.

Please consider it.

Quramy