fix link error when launching SSK tests

SignalServiceKit/tests/SSKSwiftTests.swift

@@ -4,6 +4,10 @@
 
 import XCTest
 
+/////
+// Swift Test vs. Cocoapods issue #1
+/////
+//
 // Cocoapods-generated test targets (like this one)
 // fail to link if:
 //
@@ -14,3 +18,23 @@ import XCTest
 // to our test target.
 //
 // See: https://github.com/CocoaPods/CocoaPods/issues/7170
+
+/////
+// Swift Test vs. Cocoapods issue #2
+/////
+//
+// XCode's test runner doesn't copy swift framework's required by dependencies into
+// the running test bundle.
+// It sounds similar to this issue: https://github.com/CocoaPods/CocoaPods/issues/7985
+//
+// The error output looks like this:
+//     The bundle “SignalServiceKit-Unit-Tests” couldn’t be loaded because it is damaged or missing necessary resources. Try reinstalling the bundle.
+//         [...]/SignalServiceKit-Unit-Tests.xctest/SignalServiceKit-Unit-Tests): Library not loaded: @rpath/libswiftAVFoundation.dylib
+//       Referenced from: /Users/[...]/Build/Products/Debug-iphonesimulator/SignalServiceKit/SignalServiceKit.framework/SignalServiceKit
+//       Reason: image not found)
+//     Program ended with exit code: 82
+//
+// A work around is to redundantly import any swift frameworks used by the dependencies of the test suite into this test file.
+// The error message provides a hint, i.e. "Library not loaded: @rpath/libswiftAVFoundation.dylib" is fixed with `import AVFoundation`
+import AVFoundation
+import CloudKit