fix(delayWhen): only deprecates when subscriptionDelay presents

[imcotton]

Noticed this after vscode starts showing the deprecation from jsdoc, not sure how to test this change tho.

[imcotton]

api_guardian is failing, not exactly have fixing in mind, could use some help.

[cartant]

Thanks for the PR.

... not sure how to test this change tho.

We should add some dtslint tests to make sure that the deprecations work as expected. ATM, there aren't many examples of this, as the ExpectDeprecation assertion was something that I added in anticipation of fixing up these sorts of false positives - and I've not yet got around to that. For an example, have a look at of:

rxjs/spec-dtslint/observables/of-spec.ts

Lines 122 to 139 in 338b174

	it('should deprecate correctly', () => {
	of(queueScheduler); // $ExpectDeprecation
	of(a, queueScheduler); // $ExpectDeprecation
	of(a, b, queueScheduler); // $ExpectDeprecation
	of(a, b, c, queueScheduler); // $ExpectDeprecation
	of(a, b, c, d, queueScheduler); // $ExpectDeprecation
	of(a, b, c, d, e, queueScheduler); // $ExpectDeprecation
	of(a, b, c, d, e, f, queueScheduler); // $ExpectDeprecation
	of(a, b, c, d, e, f, g, queueScheduler); // $ExpectDeprecation
	of(a, b, c, d, e, f, g, h, queueScheduler); // $ExpectDeprecation
	of(a, b, c, d, e, f, g, h, i, queueScheduler); // $ExpectDeprecation
	of<A>(); // $ExpectDeprecation
	of(); // $ExpectNoDeprecation
	of(a); // $ExpectNoDeprecation
	of(a, b); // $ExpectNoDeprecation
	of(a, b, c); // $ExpectNoDeprecation
	of(a, b, c, d); // $ExpectNoDeprecation
	});

To run the dtslint tests, use npm run dtslint.

Note that there is also an ExpectNoDeprecation assertion.

api_guardian is failing

You should be able to use npm run api_guardian:update to update its files.

[imcotton]

Updated, have spec-dtslint and api_guardian included.

[benlesh]

Thank you @imcotton