import-js/eslint-plugin-import

[import/no-unused-modules] Typescript `namespace` usage results in false positive

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#2,336 opened on Dec 24, 2021

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Description

// Foo.ts
export namespace MyNamespace {
  export interface Internal {
    a: string;
  }
}

// Bar.ts
import { MyNamespace } from 'Foo';

export const internal: MyNamespace.Internal = { a: 'a' };

/src/Foo.ts
  2:3  error  exported declaration 'Internal' not used within other modules      import/no-unused-modules

Both the export of MyNamepsace and Internal seem to be required for the usage to compile in Bar.ts. I think this kind of usage should not result in any errors. The namespace in Foo.ts can be replaced with the module keyword and the same false positive is raised.

This seems to be in a similar area to https://github.com/import-js/eslint-plugin-import/issues/1964 but with a different rule.

Contributor guide

Research direction
Investigate the `import/no unused modules` rule logic for handling TypeScript namespaces. Trace how exports from a namespace are tracked and why `Internal` is flagged as unused. Look at existing test cases for namespaces and consider if the rule needs to treat namespace members as used when the namespace itself is imported.
Tech stack
javascripttypescript
Domain
toolingdeveloper experience
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
ESLintTypeScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50