import-js/eslint-plugin-import

Feature Request: Auto-detection of side-effect only modules in no-unassigned-imports

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#1,313 opened on Mar 31, 2019

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 (2 comments) (1 reaction) (0 assignees)JavaScript (1,540 forks)batch import
enhancementhelp wanted

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Description

I'd like to request that no-unassigned-imports have the ability to scan import targets and ignore any which do not export anything. I have a number of custom elements which are side-effects only and have no default or named exports. Example:

customElements.define('my-element', class extends HTMLElement {
  /* constructor, methods, properties of `<my-element>` go here */
});

Right now for web projects I simply disable import/no-unassigned-imports, it would be nice if I could let it run with an option to allow all non-exporting modules yet still throw an error if import './something-that-exports.js'; is found.

I'm not very experienced with eslint plugins but I'm willing to try implementing if you would accept the feature (full testing will be included). It looks like I should be able to use ExportMap to determine if the module being imported has any ESM exports. Probably this auto-detect functionality needs to be enabled by an option so import './cjs-module-that-exports.js'; will still report errors by default? The option would be for use in 'pure ESM' projects (initially anyways, maybe it can be expanded later to support scanning for CJS exports).

Contributor guide

Research direction
Examine how ExportMap is used in other rules (e.g., no unused modules) to detect exports. Then implement an option (e.g., 'allowNonExporting') that, when enabled, uses ExportMap to check if the imported module has any ESM exports; if none, ignore the import. Add tests for both ESM and CJS scenarios (initially only ESM auto detect). Ensure the option defaults to false to maintain backward compatibility.
Tech stack
javascript
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.
1-2 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
ESLintJavaScriptExportMap
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65