I have the following javascript module which when the user clicks on back to top button it animates and move the page to the top.
const jsdom = require("jsdom");
const { JSDOM } = jsdom;
const { window } = new JSDOM(`...`);
var $ = require("jquery")(window);
const BackToTop = (function () {
var baclTop = () => {
$(".back").on("click", BackToTop.animate);
};
var animate = function () {
$("html, body").animate({ scrollTop: "0" }, 1000);
};
return {
baclTop,
animate,
};
})();
module.exports = BackToTop;
I have written the following test case using mocha and sinon.js but I am getting the following error
const BackToTop = require("../src/backToTop");
const sinon = require("sinon");
const jsdom = require("jsdom");
const document = new jsdom.JSDOM("<html></html>", {});
const window = document.defaultView;
global.document = document;
global.window = window;
const { expect } = require("chai");
describe("Name of the group", () => {
it("should ", (done) => {
$("body").append("<div class='sd-back-to-top'>hello world</div>");
const operation = sinon.spy(BackToTop, "animate");
$(".back").trigger('click');
BackToTop.baclTop();
expect(operation.callCount).to.be.eq(1);
done();
});
});
AssertionError: expected 0 to equal 1
at Context.<anonymous> (test\backToTop.spec.js:17:39)
at processImmediate (internal/timers.js:461:21)
+ expected - actual
-0
+1
I have already tried a lot of articles but no luck
Thanks in advance!
The
BackToTopmodule has two private (scoped) functions:baclTopandanimate.When you expose them, you are declaring another two function attached to the module:
So when you create the spy, sinon will wrap the function exposed function in the return bock:
But, whe you call
BackToTop.baclTop()this will call the "internal" version of theanimatefunction, and sinon can't intercept this call.You can't do that, you must rewrite your code in a testable way, or just spy only functions that you call directly.