---
url: /reference/@cssdoc/providers/functions/checkClassUsage.md
---
# Function: checkClassUsage()

```ts
function checkClassUsage(
   usages, 
   index, 
   severities?
): Diagnostic[];
```

Defined in: [packages/providers/src/index.ts:126](https://github.com/thedannywahl/cssdoc/blob/main/packages/providers/src/index.ts#L126)

Consumer-side diagnostics for class-attribute usage: unknown/deprecated modifiers, plus unknown
state classes (`statePrefixes`) and unknown BEM element classes, routed by the token's kind.

## Parameters

### usages

readonly [`ClassUsage`](../../index/interfaces/ClassUsage.md)\[]

### index

[`CssDocIndex`](../../index/classes/CssDocIndex.md)

### severities?

[`RuleSeverities`](../../cssdoc/type-aliases/RuleSeverities.md) = `DEFAULT_RULE_SEVERITIES`

## Returns

[`Diagnostic`](../../cssdoc/interfaces/Diagnostic.md)\[]