unicorn/consistent-existence-index-check Style
What it does
Enforce consistent style for element existence checks with indexOf(), lastIndexOf(), findIndex(), and findLastIndex(). This ensures that comparisons are performed in a standard and clear way.
Why is this bad?
This rule is meant to enforce a specific style and improve code clarity. Using inconsistent comparison styles (e.g., index < 0, index >= 0) can make the intention behind the code unclear, especially in large codebases.
Examples
Examples of incorrect code for this rule:
javascript
const index = foo.indexOf("bar");
if (index < 0) {
}
const index = foo.indexOf("bar");
if (index >= 0) {
}Examples of correct code for this rule:
javascript
const index = foo.indexOf("bar");
if (index === -1) {
}
const index = foo.indexOf("bar");
if (index !== -1) {
}How to use
To enable this rule in the CLI or using the config file, you can use:
bash
oxlint --deny unicorn/consistent-existence-index-checkjson
{
"rules": {
"unicorn/consistent-existence-index-check": "error"
}
}