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oxc/uninvoked-array-callback Correctness

✅ This rule is turned on by default.

What it does

This rule applies when an Array function has a callback argument used for an array with empty slots.

Why is this bad?

When the Array constructor is called with a single number argument, an array with the specified number of empty slots (not actual undefined values) is constructed. If a callback function is passed to the function of this array, the callback function is never invoked because the array has no actual elements.

Examples

Examples of incorrect code for this rule:

const list = new Array(5).map((_) => createElement());

Examples of correct code for this rule:

const list = new Array(5).fill().map((_) => createElement());

How to use

To enable this rule using the config file or in the CLI, you can use:

Config (.oxlintrc.json)

{
  "rules": {
    "oxc/uninvoked-array-callback": "error"
  }
}

Config (oxlint.config.ts)

import { defineConfig } from "oxlint";

export default defineConfig({
  rules: {
    "oxc/uninvoked-array-callback": "error",
  },
});

CLI

oxlint --deny oxc/uninvoked-array-callback

Version

This rule was added in v0.0.3.

References

• Rule Source
• Open rule in Oxc Playground