[5.3] Type error in typescript.d.ts with exactOptionalPropertyTypes = true

[uid11]

🔎 Search Terms

"exactOptionalPropertyTypes", "JsDocParsingMode".

🕗 Version & Regression Information

• This changed between versions 5.2.2 and 5.3.2
• I think, this changed in commit or PR Make JSDoc skipping public, plus more configurable #55739

⏯ Playground Link

No response

💻 Code

// "exactOptionalPropertyTypes": true,

import type { CompilerOptions } from "typescript";

export type { CompilerOptions };

🙁 Actual behavior

Error:

node_modules/typescript/lib/typescript.d.ts:3287:24 - error TS2420: Class 'Project' incorrectly implements interface 'LanguageServiceHost'.
  Types of property 'jsDocParsingMode' are incompatible.
    Type 'JSDocParsingMode | undefined' is not assignable to type 'JSDocParsingMode'.
      Type 'undefined' is not assignable to type 'JSDocParsingMode'.

3287         abstract class Project implements LanguageServiceHost, ModuleResolutionHost {
                            ~~~~~~~


Found 1 error in node_modules/typescript/lib/typescript.d.ts:3287

🙂 Expected behavior

No error.

Additional information about the issue

Minimal repository with bug reproduction: https://github.com/uid11/jsDocParsingMode-error-example.

As far as I can see, to fix this error, it is enough to replace the line

TypeScript/src/services/types.ts

Line 435 in c266e47

jsDocParsingMode?: JSDocParsingMode;

with

    jsDocParsingMode?: JSDocParsingMode | undefined;

Although, perhaps, such errors with exactOptionalPropertyTypes are corrected differently.

[jakebailey]

Working on this; there are more errors than just this one.