resolvePackageJsonExports false ignored in tsgo, works in v5.9 and v6

[freshp86]

Steps to reproduce

This is happening in the Chromium codebase, revealed as part of the effort to prepare for using tsgo (https://issues.chromium.org/issues/423789047).

Describing the problem briefly below and will follow-up with a minimal repro repository later on if the following is not clear. (Update: See minimal repro at https://github.com/freshp86/tsgo-repro-issue-2445)

When using tsgo, "resolvePackageJsonExports": false seems to be ignored, resulting in incorrect import URLs showing up in generated definition files (using "moduleResolution": "NodeNext"), which in turn causes other projects that consume these definition files (and don't use "skipLibCheck": true) to fail with error TS2307: Cannot find module '...' or its corresponding type declarations.

Behavior with typescript@5.9

// contents of generated cr_action_menu.d.ts file
export declare class CrActionMenuElement extends CrLitElement {
     static get styles(): import("//resources/lit/v3_0/lit.rollup.js").CSSResultGroup;
     render(): import("//resources/lit/v3_0/lit.rollup.js").TemplateResult<1>;
  ...
}

Behavior with tsgo

// contents of generated cr_action_menu.d.ts file
export declare class CrActionMenuElement extends CrLitElement {
    static get styles(): import("@lit/reactive-element/css-tag.js").CSSResultGroup;
    render(): import("lit-html").TemplateResult<1>;
  ...
}

Note the import() paths appearing in the definition file, where tsgo behaves the same as-if "resolvePackageJsonExports": true was specified, unlike v5.9 and v6 preview.

Please let me know if a fully fledged repro example is necessary to understand the reported issue. Thanks!

[freshp86]

Please let me know if a fully fledged repro example is necessary to understand the reported issue. Thanks!

Uploaded a minimal repro anyway, please see https://github.com/freshp86/tsgo-repro-issue-2445