QUnit.test running in a for loop

Question

I was trying to do some code refactoring for QUnit tests. I used a json array TestCaseSource to store test case's input and expected output, and coded like this,

var data = TestCaseSource.data;

for (var i in data) {
    console.log(data[i]);
    QUnit.test(data[i].TestCaseName, function () {
        DoProcess(data[i].TestCaseName, "", data[i]);
    });
}

With this code, I could only have the first and last test case run. All the cases in the middle were omitted by QUnit. If I removed the for loop, and hard coded QUnit.test like,

    QUnit.test('TestCaseName1', function () {
        DoProcess('TestCaseName1', "", TestCaseSource.data[0]);
    });
    QUnit.test('TestCaseName2', function () {
        DoProcess('TestCaseName2', "", TestCaseSource.data[1]);
    });
    ...

Everything was fine then. Why the for loop was not working?

score 3 · Accepted Answer · edited May 23 '17 at 12:08

I found my answer in Asynchronous Process inside a javascript for loop . As it says in this very nice post:

You have to freeze the value of i by passing it into a function somewhere so it's value exists uniquely for each iteration of the loop in a function closure. Otherwise, all asynch callbacks will just see the value of i at the end of the loop which is the value it has when they execute their callbacks (sometime later when the loop has finished), not each their own value.

QUnit.test running in a for loop

1 Answers1