Fix unit test

[4brunu]

Currently there is a breaking test, and this PR fixes it.

Here is the log of the breaking test.

androidx.test.espresso.base.DefaultFailureHandler$AssertionFailedWithCauseError: 'is displayed on the screen to the user' doesn't match the selected view.
Expected: is displayed on the screen to the user
     Got: "PDFViewPager{id=-1, visibility=GONE, width=1080, height=1584, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=true, is-layout-requested=true, is-selected=false, layout-params=android.widget.FrameLayout$LayoutParams@fe83969, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=2}"

	at dalvik.system.VMStack.getThreadStackTrace(Native Method)
	at java.lang.Thread.getStackTrace(Thread.java:1736)
	at androidx.test.espresso.base.DefaultFailureHandler.getUserFriendlyError(DefaultFailureHandler.java:88)
	at androidx.test.espresso.base.DefaultFailureHandler.handle(DefaultFailureHandler.java:51)
	at androidx.test.espresso.ViewInteraction.waitForAndHandleInteractionResults(ViewInteraction.java:314)
	at androidx.test.espresso.ViewInteraction.check(ViewInteraction.java:297)
	at es.voghdev.pdfviewpager.sample.Sample9Tests.shouldSetAClickListenerToEveryPDFPage(Sample9Tests.java:59)
	at java.lang.reflect.Method.invoke(Native Method)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at androidx.test.rule.ActivityTestRule$ActivityStatement.evaluate(ActivityTestRule.java:527)
	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at androidx.test.runner.AndroidJUnit4.run(AndroidJUnit4.java:104)
	at org.junit.runners.Suite.runChild(Suite.java:128)
	at org.junit.runners.Suite.runChild(Suite.java:27)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
	at androidx.test.internal.runner.TestExecutor.execute(TestExecutor.java:56)
	at androidx.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:388)
	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2205)
Caused by: junit.framework.AssertionFailedError: 'is displayed on the screen to the user' doesn't match the selected view.
Expected: is displayed on the screen to the user
     Got: "PDFViewPager{id=-1, visibility=GONE, width=1080, height=1584, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=true, is-layout-requested=true, is-selected=false, layout-params=android.widget.FrameLayout$LayoutParams@fe83969, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=2}"

	at androidx.test.espresso.matcher.ViewMatchers.assertThat(ViewMatchers.java:539)
	at androidx.test.espresso.assertion.ViewAssertions$MatchesViewAssertion.check(ViewAssertions.java:103)
	at androidx.test.espresso.ViewInteraction$SingleExecutionViewAssertion.check(ViewInteraction.java:415)
	at androidx.test.espresso.ViewInteraction$2.call(ViewInteraction.java:279)
	at androidx.test.espresso.ViewInteraction$2.call(ViewInteraction.java:265)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at android.os.Handler.handleCallback(Handler.java:938)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loop(Looper.java:223)
	at android.app.ActivityThread.main(ActivityThread.java:7656)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

[voghDev]

Hi!

Thanks for the PR. I'll have a look. It seems I hided the pdfViewPager for some reason when I wrote the samples, but can't guess why now. If this PR fixes the Instrumentation Tests, it's fine to merge it for me.

[4brunu]

I run the tests locally and all tests are passing now 🙂

[4brunu]

@voghDev is there any required changes to merge this PR? Thanks 🙂