I'm looking to create some jasmine specs for a piece of code that has async functionality.
In the jasmine docs it shows the example:
it("takes a long time", function(done) {
setTimeout(function() {
done();
}, 9000);
});
Using the done function and a setTimeout, my issue with this is setTimout could be fragile i.e. delays in test runs in enviros
is there an alternative solution to such tests where I don't have to use a timeout?
Thanks in advance
In this example setTimeout is actually the function being tested. It's used as a representative example of an asynchronous function. The key point is that you must explicitly call done() when your test is complete. Your code should look something like:
it("takes a long time", function(done) {
myMethod('foo', 'bar', function callback() {
assert(...)
done();
}); // callback-style
}
it("takes a long time", function(done) {
myMethod('foo', 'bar').then(function() {
assert(...)
done();
}); // promise-style
});
it("takes a long time", async function(done) {
await myMethod('foo', 'bar')
assert(...)
done()
});
The documented function is intended to illustrate using the done callback following a long-running method, and should not be used for actual tests.
Normally, you would expect a long running function to be supplied with a callback in which you would call the done function. For example, you could write a unit test involving a file that took a long time to write data:
it("writes a lot of data", function(done) {
var fd = 999; // Obtain a file descriptor in some way...
fs.write(fd, veryLongString, function (err, written, string) {
// Carry out verification here, after the file has been written
done();
});
Again, this is only illustrative, as you would generally not want to write to a file within the body of a unit test. But the idea is that you can call done after some long-running operation.
yieldand dropsetTimeout()anddone().