zadr/PipeWrench

What Is This?

PipeWrench is an iOS library that can be linked into a testing target that automatically runs leaks when a test fails, and when a test suite finishes running.

How Does It Work?

PipeWrench copies NSTask.h from the macOS SDK, and then shells out to the leaks and heap command line tool to do all the heavy lifting.

Since iOS doesn't have NSTask, this PipeWrench is limited to running on the iOS Simulator.

Why Wouldn't I Use The Memory Graph In Xcode?

Can't press buttons manually when running automated tests on CI systems. Even if you could, it would be very tedious to have to press the same button all the time.

Integration?

This is a prototype. If you want to use PipeWrench, you'll have to add it as a submodule and deal with the xcodeproj manually.

Environment Variables

There are a handful of environment variables that control PipeWrench's behavior. These are best set as part of the target's build and run configuration. Here is a brief overview of available environment variables:

EnablePipeWrench - Default: false. Should PipeWrench automatically track leaks when linked into a test target that is loaded into memory? It is not required to start PipeWrench at load-time; calling let pipeWrench = PipeWrench(logger: PWLogIngest()) ; try? pipeWrench.start() will also result in leaks being tracked, for example, on a per-test or per-test case basis.
MemgraphRootDirectory - Default: /tmp/PipeWrench/<uuid>/. Where on disk should memgraph files be saved? By default, PipeWrench will save files to a directory under /tmp/PipeWrench/ with a new uuid for each instance of PipeWrench.
CreateMemgraphRootDirectory - Default: false. If a directory to save memgraph files to does not exist, should it be created?
ConsoleLoggingEnabled - Default: true. Should PipeWrench log any output (debug or informational) to the device console?
DiskLoggingPath - Default: nil. If non-nil, PipeWrench will write any log output to a file on disk.

For more context, see swiftdoc in Constants.swift.

Running the Prototype?

Open App.xcodeproj.
Hit ⌘U to run tests. When running with Xcode 13.2.1, you'll see something like this at the end of the test run:

Test Suite 'Selected tests' started at 2022-02-19 00:30:11.360
Test Suite 'AppTests.xctest' started at 2022-02-19 00:30:11.360
Test Suite 'AppTests' started at 2022-02-19 00:30:11.360
Test Case '-[AppTests.AppTests testExample]' started.
Test Case '-[AppTests.AppTests testExample]' passed (0.001 seconds).
Test Case '-[AppTests.AppTests testPerformanceExample]' started.
/Users/z/Desktop/App/AppTests/AppTests.swift:15: Test Case '-[AppTests.AppTests testPerformanceExample]' measured [Time, seconds] average: 0.000, relative standard deviation: 154.614%, values: [0.000258, 0.000029, 0.000023, 0.000021, 0.000022, 0.000021, 0.000020, 0.000020, 0.000021, 0.000022], performanceMetricID:com.apple.XCTPerformanceMetric_WallClockTime, baselineName: "", baselineAverage: , polarity: prefers smaller, maxPercentRegression: 10.000%, maxPercentRelativeStandardDeviation: 10.000%, maxRegression: 0.100, maxStandardDeviation: 0.100
Test Case '-[AppTests.AppTests testPerformanceExample]' passed (0.264 seconds).
Test Suite 'AppTests' passed at 2022-02-19 00:30:11.626.
	 Executed 2 tests, with 0 failures (0 unexpected) in 0.265 (0.266) seconds
Test Suite 'AppTests.xctest' passed at 2022-02-19 00:30:11.626.
	 Executed 2 tests, with 0 failures (0 unexpected) in 0.265 (0.266) seconds
Test Suite 'Selected tests' passed at 2022-02-19 00:30:11.627.
	 Executed 2 tests, with 0 failures (0 unexpected) in 0.265 (0.267) seconds
leaking :(
Process:         App [78941]
Path:            /Users/z/Library/Developer/CoreSimulator/Devices/87C655D7-8376-41BF-81D5-9CE1B66680EC/data/Containers/Bundle/Application/60DB5134-FD92-4EE6-87DB-ECD7746A47BD/App.app/App
Load Address:    0x102fd4000
Identifier:      App
Version:         ???
Code Type:       ARM64
Parent Process:  debugserver [78942]

Date/Time:       2022-02-19 00:30:12.040 -0800
Launch Time:     2022-02-19 00:30:10.689 -0800
OS Version:      iPhone OS 15.2 (19C51)
Report Version:  7
Analysis Tool:   /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/bin/leaks
Analysis Tool Version:  iOS Simulator 15.2 (19C51)

Physical footprint:         12.5M
Physical footprint (peak):  12.5M
----

leaks Report Version: 4.0
Process 78941: 31480 nodes malloced for 4419 KB
Process 78941: 1 leak for 32 total leaked bytes.

    1 (32 bytes) ROOT LEAK: 0x6000017ebc40 [32]

which tells us there is one leak found, along with the memory address.

License

PipeWrench is available under the MIT license.

zadr / PipeWrench