# core/validators/concern.validator.ts

> 23 lines of code and 3 definitions.

Tree: GovLab Quality
Language: typescript
Layer: processing
Canonical: https://banes-lab.com/anatomy/quality#file-quality-core-validators-concern-validator-ts
Source text: https://banes-lab.com/source/quality/core/validators/concern.validator.ts.txt

Listed in [core/validators](https://banes-lab.com/api/source/quality/core/validators.md), after [core/validators/binding.validator.ts](https://banes-lab.com/source/quality/core/validators/binding.validator.ts.md) and before [core/validators/constants.validator.ts](https://banes-lab.com/source/quality/core/validators/constants.validator.ts.md).

## Definitions

- `isConcernConfig` (lexical_declaration, line 6)
- `validateConcerns` (lexical_declaration, line 10, exported)
- `unknown` (lexical_declaration, line 20, exported)

## Contained in

- [core/validators](https://banes-lab.com/anatomy/quality/folder-quality-core-validators.md)

## Uses

- [configuration/strings/quality.strings.ts](https://banes-lab.com/source/quality/configuration/strings/quality.strings.ts.md)
- [core/selectors/concept.selector.ts](https://banes-lab.com/source/quality/core/selectors/concept.selector.ts.md)

## Linked from

- [configuration/strings](https://banes-lab.com/anatomy/quality/folder-quality-configuration-strings.md)
- [core/selectors](https://banes-lab.com/anatomy/quality/folder-quality-core-selectors.md)
- [core/validators](https://banes-lab.com/anatomy/quality/folder-quality-core-validators.md)

## Source

```typescript
import { concernsShape, unknownConcept } from "#configuration/strings/quality.strings";
import type { ConcernConfig } from "#types/concern.types";
import { isRecord } from "#core/selectors/record.selector";
import { validConcepts } from "#core/selectors/concept.selector";

const isConcernConfig = function isConcernConfig(value: unknown): value is ConcernConfig {
    return isRecord(value);
};

export const validateConcerns = function validateConcerns(
    concerns: unknown,
    valid: ReadonlySet<string> = validConcepts(),
): ConcernConfig {
    if (!isConcernConfig(concerns)) {
        throw new Error(concernsShape(Array.isArray(concerns) ? "array" : typeof concerns));
    }
    if (valid.size === 0) {
        return concerns;
    }
    const unknown = Object.keys(concerns).find((key) => !valid.has(key));
    if (unknown !== undefined) {
        throw new Error(unknownConcept(unknown, valid.size));
    }
    return concerns;
};
```