We will now create our first integration tests. Each of our tests will run separately, meaning they should not depend on any other test and should follow a predictable workflow. First, we need to change our run.js file to run all test files. For that, we'll use mocha and add all files found in the integration folder:

const fs    = require("fs");
const path  = require("path");
const mocha = require("mocha");
const suite = new mocha();

fs.readdir(path.join(__dirname, "integration"), (err, files) => {
    if (err) throw err;

    files.filter((filename) => 
    (filename.match(/.js$/))).map((filename) => {
        suite.addFile(path.join(__dirname, "integration", filename));
    });

    suite.run((failures) => {
        process.exit(failures);
    });
});

Then, let's create the integration folder inside our test folder, and let's create our first test file, called image-upload.js. Add this content to the file:

describe("Uploading image", () => {
    it("should accept only images");
});

If we now run the tests again, we should see the default mocha response with no tests passing and no tests failing:

npm test
> [email protected] test /Users/dresende/imagini
> node test/run

0 passing (2ms)

To avoid repeating code, let's create a tools.js file inside the test folder, so we can export common tasks that every test file can use. Out of the box, I'm thinking about our microservice location and a sample image:

const fs   = require("fs");
const path = require("path");

exports.service = require("../imagini.js");
exports.sample  = fs.readFileSync(path.join(__dirname, "sample.png"));

Create a sample.png image in the test folder. When a test needs to upload an image, it will use that sample. In the future, we could have different kinds of samples, such as huge images, to test performance and limitations.