Issue with @testable import test

[remirobert]

I am currently having an issue, in my tests, I am using @testable import to access the API code I want to test.

Here my BUCK:

buck test :chatApp

apple_asset_catalog(
  name = 'Assets',
  app_icon = 'AppIcon',
  dirs = ['app/Assets.xcassets'],
)

apple_resource(
  name = 'appResources',
  files = glob(['app/*.png', 'app/**/*.storyboard']),
)

apple_bundle(
  name = 'app',
  binary = ':appBinary',
  extension = 'app',
  info_plist = 'app/Info.plist',
  tests = [':appTests']
)

apple_binary(
  name = 'appBinary',
  deps = [':appResources', ':Assets'],
  srcs = glob([
    'app/**/*.swift'
  ]),
  frameworks = [
    '$SDKROOT/System/Library/Frameworks/UIKit.framework',
    '$SDKROOT/System/Library/Frameworks/Foundation.framework',
  ]
)

apple_package(
  name = 'appPackage',
  bundle = ':app'
)

apple_test(
  name = 'appTests',
  test_host_app = ':app',
  run_test_separately = True,
  info_plist = 'appTests/Info.plist',
  srcs = glob([
    'appTests/**/*.swift'
  ]),
  frameworks = [
    '$SDKROOT/System/Library/Frameworks/Foundation.framework',
    '$SDKROOT/System/Library/Frameworks/UIKit.framework',
    '$PLATFORM_DIR/Developer/Library/Frameworks/XCTest.framework',
  ]
)

I am having a runtime crash.
Is it possible to have the @testable import?
If not what is the other alternative to test my code?

Here the error :

Building... 0.4 sec
[2017-12-18 16:21:26.111][error][command:null][tid:465][com.facebook.buck.cli.Main] Uncaught exception at top level
java.lang.NullPointerException
	at java.util.Objects.requireNonNull(Objects.java:203)
	at java.util.Optional.<init>(Optional.java:96)
	at java.util.Optional.of(Optional.java:108)
	at com.facebook.buck.apple.AppleTestDescription.createTestHostInfo(AppleTestDescription.java:496)
	at com.facebook.buck.apple.AppleTestDescription.createBuildRule(AppleTestDescription.java:233)
	at com.facebook.buck.apple.AppleTestDescription.createBuildRule(AppleTestDescription.java:84)
	at com.facebook.buck.rules.DefaultTargetNodeToBuildRuleTransformer.transform(DefaultTargetNodeToBuildRuleTransformer.java:88)
	at com.facebook.buck.rules.SingleThreadedBuildRuleResolver.lambda$requireRule$0(SingleThreadedBuildRuleResolver.java:111)
	at com.facebook.buck.rules.SingleThreadedBuildRuleResolver.computeIfAbsent(SingleThreadedBuildRuleResolver.java:84)
	at com.facebook.buck.rules.SingleThreadedBuildRuleResolver.requireRule(SingleThreadedBuildRuleResolver.java:107)
	at com.facebook.buck.swift.SwiftLibraryDescription.createCompanionBuildRule(SwiftLibraryDescription.java:391)
	at com.facebook.buck.apple.AppleLibraryDescription.lambda$requireSingleArchUnstrippedBuildRule$8(AppleLibraryDescription.java:587)
	at java.util.Optional.flatMap(Optional.java:241)
	at com.facebook.buck.apple.AppleLibraryDescription.requireSingleArchUnstrippedBuildRule(AppleLibraryDescription.java:585)
	at com.facebook.buck.apple.AppleLibraryDescription.requireUnstrippedBuildRule(AppleLibraryDescription.java:546)
	at com.facebook.buck.apple.AppleLibraryDescription.createLibraryBuildRule(AppleLibraryDescription.java:441)
	at com.facebook.buck.apple.AppleTestDescription.createTestLibraryRule(AppleTestDescription.java:411)
	at com.facebook.buck.apple.AppleTestDescription.createBuildRule(AppleTestDescription.java:251)
	at com.facebook.buck.apple.AppleTestDescription.createBuildRule(AppleTestDescription.java:84)
	at com.facebook.buck.rules.DefaultTargetNodeToBuildRuleTransformer.transform(DefaultTargetNodeToBuildRuleTransformer.java:88)
	at com.facebook.buck.rules.SingleThreadedBuildRuleResolver.lambda$requireRule$0(SingleThreadedBuildRuleResolver.java:111)
	at com.facebook.buck.rules.SingleThreadedBuildRuleResolver.computeIfAbsent(SingleThreadedBuildRuleResolver.java:84)
	at com.facebook.buck.rules.SingleThreadedBuildRuleResolver.requireRule(SingleThreadedBuildRuleResolver.java:107)
	at com.facebook.buck.rules.ActionGraphCache$2.visit(ActionGraphCache.java:330)
	at com.facebook.buck.rules.ActionGraphCache$2.visit(ActionGraphCache.java:327)
	at com.facebook.buck.graph.AbstractBottomUpTraversal.traverse(AbstractBottomUpTraversal.java:36)
	at com.facebook.buck.rules.ActionGraphCache.createActionGraphSerially(ActionGraphCache.java:332)
	at com.facebook.buck.rules.ActionGraphCache.createActionGraph(ActionGraphCache.java:264)
	at com.facebook.buck.rules.ActionGraphCache.getActionGraph(ActionGraphCache.java:167)
	at com.facebook.buck.rules.ActionGraphCache.getActionGraph(ActionGraphCache.java:68)
	at com.facebook.buck.cli.TestCommand.runWithoutHelp(TestCommand.java:549)
	at com.facebook.buck.cli.AbstractCommand.run(AbstractCommand.java:232)
	at com.facebook.buck.cli.AbstractContainerCommand.run(AbstractContainerCommand.java:79)
	at com.facebook.buck.cli.BuckCommand.run(BuckCommand.java:82)
	at com.facebook.buck.cli.Main.runMainWithExitCode(Main.java:1101)
	at com.facebook.buck.cli.Main.runMainThenExit(Main.java:395)
	at com.facebook.buck.cli.Main.nailMain(Main.java:1855)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.martiansoftware.nailgun.NGSession.run(NGSession.java:329)

[zayhero-zz]

@remirobert are you using the sample repo or your own repo? I didn't see anything related to @testable here.

[remirobert]

My own.
On this repo, there is no test target.
So if you want to test your app, how will you do?

[zayhero-zz]

Buck itself provide the guideline about how to config apple_test build rule: https://buckbuild.com/rule/apple_test.html
We are able to use @testable in our codebase, which is doing almost the same thing as what we do in apple_library.

In our migration, we did encounter some cases that @testable fail, but that's mostly due to there is swift module in the module which being tested.
But without looking into your code / config, I can't tell what's exactly broken.

[remirobert]

I have read the documentation, and tried different settings, but at this end I always got that runtime crash.
I created a sample project with the configuration I am using, and reproducing the crash with a test target : https://github.com/remirobert/test-fail-testable-import

Thanks for your help.

[zayhero-zz]

you need to add deps = [':app'] into the apple_test build rule so that you can use the app module.
Also, your crash is due to use are setting test_host_app = ':app', I think that's probably not the correct way, I remove this line and the test is able to build

[remirobert]

Yes without the test_host_app = ':app' it's building fine.
But I can't use the @testable import app in my tests.
My understanding is that test_host_app allows you to do that.

[remirobert]

I found an Objc example working with the test_host_app : https://github.com/bhamiltoncx/buck-ios-sample

[zayhero-zz]

Nope, it’s not related. You need to put “deps” into the test build rule to make it build.

[zayhero-zz]

Closing this since the problem should have been resolved

[pomozoff]

@zayhero, Still doesn't build even adding deps = [':app'], into BUCK:

apple_test(
  name = 'appTests',
  deps = [':app'],
  test_host_app = ':app',
  run_test_separately = True,
  info_plist = 'appTests/Info.plist',
  srcs = glob([
    'appTests/**/*.swift'
  ]),
  frameworks = [
    '$SDKROOT/System/Library/Frameworks/Foundation.framework',
    '$SDKROOT/System/Library/Frameworks/UIKit.framework',
    '$PLATFORM_DIR/Developer/Library/Frameworks/XCTest.framework',
  ]
)

[pomozoff]

@remirobert, it builds because there are no swift sources in srcs section added.
I'm debugging buck and see it tries to build a SwiftLibrary that has no output path and this is the root cause of the NPE.