[SR-1872] Use runloop source in XCTestCase.waitForExpectations(withTimeout:file:line:handler:)

[modocache]

Previous ID	SR-1872
Radar	None
Original Reporter	@modocache
Type	Improvement
Status	In Progress
Resolution

Additional Detail from JIRA

Votes	0
Component/s	XCTest
Labels	Improvement, StarterBug
Assignee	pranavShenoy95 (JIRA)
Priority	Medium

md5: 2f80d90c1c1340fe3c193450551b82f7

Issue Description:

See this FIXME:

"Instead of polling the expectations to check whether they've been fulfilled, it would be more efficient to use a runloop source that can be signaled to wake up when an expectation is fulfilled."

Prerequisites:

• A development environment capable of building Swift from source.

Helpful skills:
Familiarity with Swift, XCTest, and Foundation's NSRunLoop.

Starting point:

1. Build Swift from source by following the instructions in the Swift README.

2. Build and run the swift-corelibs-xctest tests by following the instructions in the swift-corelibs-xctest README. Confirm that all the tests pass.

3. Modify the source code in XCTestCase+Asynchronous.swift to use a runloop source. The Apple documentation on run loops might be helpful.

4. Run the swift-corelibs-xctest tests again. Confirm they all still pass. If they do, send a pull request!

[belkadan]

Resetting assignee on all Starter Bugs not modified since 2018.

[swift-ci]

Comment by Kazuhiro Hayashi (JIRA)

Has someone already fixed this issue? I want to try. 🙂

[swift-ci]

Comment by Kazuhiro Hayashi (JIRA)

This issue has been fixed by the following commit?

ffa81a2#diff-3bcbfe3df724d74e85b7c115710eaa7aR370

[belkadan]

cc @stmontgomery

[stmontgomery]

kazuhiro4949 (JIRA User) No I don't believe that PR addressed this, so it's still outstanding. Feel free to submit a PR!

[swift-ci]

Comment by pranav (JIRA)

@stmontgomery @belkadan @modocache Could you please help me in merging the pull request for the task? This pull request has been blocked for a while due to a dependency in Foundation framework (in wrappers for CFRunloopContext). I have root caused the issue (crash) but not sure about the best solution.

Please help me in merging this pull request. Thanks.

Link to pull request: #304

cc: @millenomi @compnerd

[grynspan]

Incorrectly closed the issue as wontfix—forgot swift-corelibs-foundation had added SPI to allow implementing something here. My bad.