jfmengels/eslint-plugin-fp

Rule proposal: no-functions-without-parameters

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#7 opened on Aug 28, 2016

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Description

Rule proposal: Forbid functions that do not take parameters.

Functions that do not take parameters are either

  • using arguments to do some odd behavior. There is a different rule for that, but still
  • has side-causes : uses variables besides closure variables or parameters
  • always return the same value: The function call could be replaced by the value itself.

I do wonder about methods that are not assigned, like for the following example

const count = values
  .map(() => 1)
  .reduce((a, b) => a + b, 0);

This should be allowed, and I think that having the function not be assigned and not declared on its own (i.e., passed as an expression) should be allowed, but I'm not sure whether this should be behind a flag or not.

If people are watching, would gladly get some feedback on this :)

Contributor guide

Research direction
Study existing ESLint rule implementations in this plugin to understand the pattern for creating a new rule. Learn about the AST representation of function declarations and expressions using astexplorer.net or similar tool. Determine how to differentiate between named function declarations, anonymous function expressions, and arrow functions. Consider exceptions for functions used as callbacks (e.g., in array methods) and decide whether to allow them by default or via a flag. Check if there are any existing rules in the plugin that handle similar function related checks.
Tech stack
javascript
Domain
developer experience
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
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
JavaScriptESLintAST
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50