Resemble.js/nodejs-tests/compareImages.test.js

/* eslint-env jest*/

const compareImages = require("../compareImages");
const fs = require("fs");

describe("compareImages", () => {
    test("works with buffers", async () => {
        const data = await compareImages(
            fs.readFileSync("./demoassets/People.jpg"),
            fs.readFileSync("./demoassets/People2.jpg")
        );

        expect(data.isSameDimensions).toBe(true);
        expect(data.misMatchPercentage).toEqual("8.66");

        const buffer = data.getBuffer();

        expect(buffer).toBeInstanceOf(Buffer);
        expect(buffer.length).toBe(91876);

        const comparison = fs.readFileSync(
            "./nodejs-tests/assets/PeopleComparedToPeople2.png"
        );

        expect(buffer.equals(comparison)).toBe(true);

        const buffer2 = data.getBuffer(true);
        const comparison2 = fs.readFileSync(
            "./nodejs-tests/assets/PeopleComparedToPeople2WithOriginal.png"
        );
        expect(buffer2.equals(comparison2)).toBe(true);
    });

    test("throws when failed", async () => {
        const promise = compareImages(
            fs.readFileSync("./demoassets/People.jpg"),
            "bogus data"
        );
        await expect(promise).rejects.toMatch(
            "Error: error while reading from input stream"
        );
    });
});