Test file:

jest.mock("mssql", () => ({
    connect: jest.fn((config, callback) => {
        if (config === "validConfig") {
            callback(null);
        } else {
            callback(new Error("Connect Error"));
        }
    }),
    query: jest.fn((queryString, callback) => {
        if (queryString.includes("02878")) {
            callback(null, { recordsets: [[{ ZipCode: "02878" }]] });
        } else {
            callback(new Error("Query error"), null);
        }
    }),
}));

const config = require("../../src/configurations/config.js");
const regionalization = require("../../src/controller/regionalization.js");

describe("Regionalization API", () => {
    beforeEach(() => {});

    it("should call sql.connect", async () => {
        config.dbConnection = "validConfig";
        const response = await regionalization.regionalizationAPI("02878");
        expect(response.status).toEqual(200);
    });

    it("should call sql.connect and return an error", async () => {
        config.dbConnection = "notValidConfig";
        const response = await regionalization.regionalizationAPI("02878");
        expect(response.status).toEqual(200);
    });

    it("should return error: invalid zip code", async () => {
        const response = await regionalization.regionalizationAPI("0287");
        expect(response.status).toEqual(500);
    });
});

The second unit test fails with the following error:

Regionalization API › should call sql.connect and return an error

thrown: Exceeded timeout of 5000 ms for a test.
Add a timeout value to this test to increase the timeout, if this is a long-running test. See .

Here is the content of the file being tested:

async function regionalizationAPI(zipCode) {
    return new Promise((resolve, reject) => {
        const zipCodeRegEx = new RegExp(/^\d{5}(?:[-s]\d{4})?$/);
        const isValidZipCode = zipCodeRegEx.test(zipCode);

        if (isValidZipCode) {
            sql.connect(config.dbConnection, (err) => {
                if (err) {
                    console.log(err);
                } else {
                    sql.query(`select * from dbo.XXX where zipcode = '${zipCode}';`, (err, result) => {
                        if (err) {
                            logger.info("Error executing call: ", err);
                        } else {
                            resolve({ status: httpStatusCodes.StatusCodes.OK, apiResponse: result.recordsets[0][0].ZipCode });
                        }
                    });
                }
            });
        } else {
            logger.info("Invalid zipcode: ", zipCode);

            errorResponse = errorHandler.RegionalizationError(httpStatusCodes.StatusCodes.INTERNAL_SERVER_ERROR, "Invalid zipcode");

            resolve({ status: httpStatusCodes.StatusCodes.INTERNAL_SERVER_ERROR, apiResponse: errorResponse });
        }
    });
}

When I remove the second unit test the tests run. Is there something that needs to be reset before/after each unit test?