# core/guards/site.guard.ts

> 9 lines of code and 1 definition.

Tree: Bane's Lab Build Scripts
Language: typescript
Layer: infrastructure
Canonical: https://banes-lab.com/anatomy/build-scripts#file-build-scripts-core-guards-site-guard-ts
Source text: https://banes-lab.com/source/build-scripts/core/guards/site.guard.ts.txt

Listed in [core/guards](https://banes-lab.com/api/source/build-scripts/core/guards.md), after [core/guards/catalog.guard.ts](https://banes-lab.com/source/build-scripts/core/guards/catalog.guard.ts.md).

## Definitions

- `ontologyOf` (lexical_declaration, line 5, exported)

## Contained in

- [core/guards](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-core-guards.md)

## Uses

- [configuration/strings/site.strings.ts](https://banes-lab.com/source/build-scripts/configuration/strings/site.strings.ts.md)

## Used by

- [core/steps/graph.step.ts](https://banes-lab.com/source/build-scripts/core/steps/graph.step.ts.md)

## Linked from

- [configuration/strings](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-configuration-strings.md)
- [core/steps](https://banes-lab.com/anatomy/build-scripts/folder-build-scripts-core-steps.md)

## Source

```typescript
import type { BuiltOntology } from "#types/ontology.types";
import type { SiteState } from "#types/site.types";
import { missingOntology } from "#configuration/strings/site.strings";

export const ontologyOf = function ontologyOf(state: SiteState, step: string): BuiltOntology {
    if (state.ontology === null) {
        throw new Error(missingOntology(step));
    }
    return state.ontology;
};
```