# test.govlab/stats/core/loaders/data.loader.test.ts

> 21 lines of code and 0 definitions.

Tree: Codebase Testing
Language: typescript
Canonical: https://banes-lab.com/anatomy/testing#file-testing-test-govlab-stats-core-loaders-data-loader-test-ts
Source text: https://banes-lab.com/source/testing/test.govlab/stats/core/loaders/data.loader.test.ts.txt

Listed in [test.govlab/stats/core/loaders](https://banes-lab.com/api/source/testing/test.govlab/stats/core/loaders.md), after [test.govlab/stats/core/loaders/config.loader.test.ts](https://banes-lab.com/source/testing/test.govlab/stats/core/loaders/config.loader.test.ts.md) and before [test.govlab/stats/core/loaders/document.loader.test.ts](https://banes-lab.com/source/testing/test.govlab/stats/core/loaders/document.loader.test.ts.md).

## Contained in

- [test.govlab/stats/core/loaders](https://banes-lab.com/anatomy/testing/folder-testing-test-govlab-stats-core-loaders.md)

## Source

```typescript
import { afterAll, describe, expect, it } from "vitest";
import { mkdtempSync, rmSync } from "node:fs";
import { join } from "node:path";
import { readJson } from "@govlab/stats/core/loaders/data.loader.ts";
import { tmpdir } from "node:os";
import { writeVerbatim } from "@govlab/canonical-write";

const root = mkdtempSync(join(tmpdir(), "data-loader-"));

afterAll(() => {
    rmSync(root, { force: true, recursive: true });
});

describe("readJson", () => {
    it("parses a file, reads null for a missing one, and throws on malformed content", () => {
        const file = join(root, "probe.json");
        const malformed = join(root, "malformed.json");
        writeVerbatim(file, '{ "name": "probe" }\n');
        writeVerbatim(malformed, "{ not json\n");
        expect(readJson(file)).toStrictEqual({ name: "probe" });
        expect(readJson(join(root, "absent.json"))).toBeNull();
        expect(() => readJson(malformed)).toThrow(SyntaxError);
    });
});
```