import-js/eslint-plugin-import

[no-unused-modules] Improve for "import * as __ from __"

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#1,775 opened on May 21, 2020

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 (6 comments) (1 reaction) (0 assignees)JavaScript (4,946 stars) (1,540 forks)batch import
enhancementhelp wantedrule proposal

Description

If a file with named exports is imported as import * as xxx from './xxx' the rule assumes that all exports of this file have been used.

Would it be possible to report exports that never have been accessed?

Example:

given file-f:

import * as fileG from './file-g'

const x = fileG.a
fileG.b()

and file-g

export const a = 7 // will not be reported
export const b = () => {} // will not be reported
export const c = 5 // will be reported

Of course this can only work as long as a module is not access like this:

import * as fileG from './fileG'
fileG['b']()

In this case the current behaviour would apply and nothing would be reported.

We heavily rely on the import * as __ from __ syntax, so we would rely profit from this change. In any case, thanks a lot for all the effort that went into that plugin already!

Contributor guide

Tech stack
javascriptnodejs
Domain
toolingdeveloper experience
Issue type
feature
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.
3-5 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Understanding of ESLint plugin architectureKnowledge of AST traversalFamiliarity with import * as syntax
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
The issue requests enhancing the `no unused modules` rule to track usage of named exports when imported via `import * as`. Currently, the rule assumes all exports are used. The implementation likely involves modifying the rule logic in the file `src/rules/no unused modules.js` and its tests. One approach is to analyze the properties accessed on the namespace object (e.g., `fileG.a`). The comment mentions an example of `fileG['b']()` which is dynamic access and may be ignored. The PRs and comments on the issue may provide additional context. No existing PRs are linked.