问题
I'm building an iOS 9 App with Swift 2 and Xcode 7.
My app runs fine when deploying it to my phone but when I run any unit test, I get the following error message for a lot of classes:
Class _TtC5<AppName>19<ClassName> is implemented in both /Users/<Username>/Library/Developer/CoreSimulator/Devices/<UUID>/data/Containers/Bundle/Application/<UUID</<AppName>.app/<AppName> and /Users/<Username>/<Path/To/Workspace>/DerivedData/<AppName>/Build/Products/Debug-iphonesimulator/<AppName>.xctest/<AppName>. One of the two will be used. Which one is undefined.
Any ideas?
回答1:
Only add the test class to your test target and none of the iPhone app classes. Then simply import your app name as a module on top of your test class to get access to all app classes.
import MyAppName
回答2:
Duplicated class implementations while running the test suite: in my case, since the test target has a host app, you don’t need to link the third-party frameworks. I had to clean the "Other Linker Flags" (OTHER_LDFLAGS) from Build Settings because it was linking to all CocoaPods of the workspace.
回答3:
The answer by @Mundi is correct for some cases.
However, I experienced the same error and what was causing it is that the libPods.a file for Cocoa Pods was being linked in the app target and the test target.
来源：https://stackoverflow.com/questions/33127896/ios-unit-testing-class-is-implemented-in-both