validate-json-by-json-schema-action/src/validation.test.ts

import { beforeEach, describe, expect, it, vi } from "vitest";
import { validateJson } from "./validation";

global.fetch = vi.fn();

const validSchema = JSON.stringify({
  $id: "https://t00n.de/schema.json",
  title:
    "JSON schema for Renovate 43.244.4 config files (https://renovatebot.com/)",
  $schema: "http://json-schema.org/draft-07/schema#",
  type: "object",
  properties: {
    $schema: {
      type: "string",
    },
    name: {
      type: "string",
    },
  },
  required: ["name"],
  additionalProperties: false,
});

describe("validateJson()", () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  it("throws an error if the JSON file is not valid JSON", async () => {
    const jsonFile = {
      despiteThisBeingValidJson: "toString() breaks it, making it invalid",
    }.toString();
    await expect(validateJson(jsonFile)).rejects.toThrow(
      '"[object Object]" is not valid JSON',
    );
  });

  it("throws an error if the JSON file does not contain a $schema property", async () => {
    const jsonFile = JSON.stringify({
      validJson: true,
    });
    await expect(validateJson(jsonFile)).rejects.toThrow(
      "No schema found in JSON file.",
    );
  });

  it("throws an error if the schema cannot be fetched", async () => {
    vi.mocked(fetch).mockRejectedValue(new Error("Failed to fetch schema"));
    const jsonFile = JSON.stringify({ $schema: "http://t00n.de/404.json" });
    await expect(validateJson(jsonFile)).rejects.toThrow(
      "Failed to fetch schema",
    );
  });

  it("throws an error if the schema file is not valid", async () => {
    vi.mocked(fetch).mockResolvedValue(
      // @ts-expect-error - mock response
      {
        ok: true,
        text: async () =>
          ({
            despiteThisBeingValidJson:
              "toString() breaks it, making it invalid",
          }).toString(),
      },
    );

    const jsonFile = JSON.stringify({
      $schema: "https://json-schema.org/draft-07/schema",
    });
    await expect(validateJson(jsonFile)).rejects.toThrow(
      '"[object Object]" is not valid JSON',
    );
  });

  it("throws an error if the JSON file does not match the schema", async () => {
    vi.mocked(fetch).mockResolvedValue(
      // @ts-expect-error - mock response
      {
        ok: true,
        text: async () => validSchema,
      },
    );

    const jsonFile = JSON.stringify({
      $schema: "https://json-schema.org/draft-07/schema",
      notTheExpectedField: 42,
    });
    await expect(validateJson(jsonFile)).rejects.toThrow(
      "JSON file is not valid: No errors",
    );
  });

  it("does not throw an error if the JSON file is valid", async () => {
    vi.mocked(fetch).mockResolvedValue(
      // @ts-expect-error - mock response
      {
        ok: true,
        text: async () => validSchema,
      },
    );

    const jsonFile = JSON.stringify({
      $schema: "https://t00n.de/schema.json",
      name: "John Doe",
    });
    await expect(validateJson(jsonFile)).resolves.toBeUndefined();
  });
});