== Why is this an issue?

When using testing frameworks like Mocha and Jest, appending `.only()` to the test function allows running a single test case for a file. Using `.only()` means no other test from this file is executed. This is useful when debugging a specific use case. 

[source,javascript,diff-id=1,diff-type=noncompliant]
----
describe("MyClass", function () {
    it.only("should run correctly", function () { // Noncompliant
        /*...*/
    });
});
----

However, it should not be used in production or development, as it is likely a leftover from debugging and serves no purpose in those contexts. It is strongly recommended not to include `.only()` usages in version control.

[source,javascript,diff-id=1,diff-type=compliant]
----
describe("MyClass", function () {
    it("should run correctly", function () {
        /*...*/
    });
});
----

== Resources

=== Documentation

* Mocha Documentation - https://mochajs.org/#exclusive-tests[Exclusive tests]
* Jest Documentation - https://jestjs.io/docs/next/api#testonlyname-fn-timeout[``++test.only()++``]
* Jest Documentation - https://jestjs.io/docs/next/api#describeonlyname-fn[``++describe.only()++``]