How to test fragments by using Espresso?

Issue

Hi I am trying to test the fragments using Espresso. I am having two buttons in a activity and I am replacing the fragments while click the button. My XML is following.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <Button
        android:id="@+id/button1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Fragment No.1"
        android:onClick="selectFrag" />

    <Button
        android:id="@+id/button2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="selectFrag"
        android:text="Fragment No.2" />

    <fragment
        android:name="com.example.admin1.espressotestingsample.fragment.FragmentOne"
        android:id="@+id/fragment_place"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

I am having two fragments. Each fragment having a button and textview.

The fragments are

FragmentOne XML:-

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:background="@android:color/holo_blue_bright">

    <TextView
        android:textSize="28dp"
        android:id="@+id/fragment_textview_one"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="First Fragment"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:textColor="@android:color/white"
        />

    <Button
        android:id="@+id/fragment_button_one"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button One"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

FragmentTwo XML:

<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:background="@android:color/holo_orange_dark">

    <TextView
        android:textSize="28dp"
        android:id="@+id/fragment_textview_two"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Second Fragment"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:textColor="@android:color/white"/>

    <Button
        android:id="@+id/fragment_button_two"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button Two"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

My Activity code is

public class ActivityFragment extends FragmentActivity {

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fragment_activity);
        getSupportFragmentManager().beginTransaction()
                .replace(R.id.fragment_place, new FragmentOne()).addToBackStack(null)
                .commit();
    }

    public void selectFrag(View view) {
        Fragment fr;

        if(view == findViewById(R.id.button2)) {
            fr = new FragmentTwo();

        }else {
            fr = new FragmentOne();
        }

        getSupportFragmentManager().beginTransaction()
                .replace(R.id.fragment_place, fr).addToBackStack(null)
                .commit();

    }
}

My test case are following.

 @Rule
    public ActivityTestRule<ActivityFragment> testRule =
            new ActivityTestRule<>(ActivityFragment.class);

    @Before
    public void init(){
        testRule.getActivity()
                .getSupportFragmentManager().beginTransaction();
    }

@Test
public void testSecondFragment() {  
  onView(withId(R.id.button2)).perform(click());
  onView(allOf(withId(R.id.fragment_textview_two),withEffectiveVisibility(VISIBLE))).
check(matches(isDisplayed()));
}

When I run this test it's working fine. But when I try the second one I am getting error.

@Test
public void testFirstFragment() {  
  onView(withId(R.id.button1)).perform(click());
  onView(allOf(withId(R.id.fragment_textview_one),withEffectiveVisibility(VISIBLE))).
check(matches(isDisplayed()));
}

But when I run this test I am getting the following error.

android.support.test.espresso.AmbiguousViewMatcherException: '(with id: com.example.admin1.espressotestingsample:id/fragment_textview_one and view has effective visibility=VISIBLE)' matches multiple views in the hierarchy.
Problem views are marked with '****MATCHES****' below.

View Hierarchy:
+>DecorView{id=-1, visibility=VISIBLE, width=1080, height=1920, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params={(0,0)(fillxfill) ty=BASE_APPLICATION wanim=0x10302f8
fl=LAYOUT_IN_SCREEN LAYOUT_INSET_DECOR SPLIT_TOUCH HARDWARE_ACCELERATED DRAWS_SYSTEM_BAR_BACKGROUNDS
pfl=FORCE_DRAW_STATUS_BAR_BACKGROUND}, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=3}
|
+->LinearLayout{id=-1, visibility=VISIBLE, width=1080, height=1794, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.widget.FrameLayout$LayoutParams@704500d, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=2}
|
+-->ViewStub{id=16908682, res-name=action_mode_bar_stub, visibility=GONE, width=0, height=0, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=true, is-selected=false, layout-params=android.widget.LinearLayout$LayoutParams@4483bc2, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0}
|
+-->FrameLayout{id=16908290, res-name=content, visibility=VISIBLE, width=1080, height=1731, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.widget.LinearLayout$LayoutParams@e334d10, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=63.0, child-count=1}
|
+--->LinearLayout{id=-1, visibility=VISIBLE, width=1080, height=1731, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.widget.FrameLayout$LayoutParams@9682a3c, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=3}
|
+---->Button{id=2131165220, res-name=button1, visibility=VISIBLE, width=1080, height=126, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=true, is-enabled=true, is-focused=false, is-focusable=true, is-layout-requested=false, is-selected=false, layout-params=android.widget.LinearLayout$LayoutParams@4a073c5, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, text=Fragment No.1, input-type=0, ime-target=true, has-links=false}
|
+---->Button{id=2131165221, res-name=button2, visibility=VISIBLE, width=1080, height=126, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=true, is-enabled=true, is-focused=false, is-focusable=true, is-layout-requested=false, is-selected=false, layout-params=android.widget.LinearLayout$LayoutParams@af5811a, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=126.0, text=Fragment No.2, input-type=0, ime-target=false, has-links=false}
|
+---->ConstraintLayout{id=2131165244, res-name=fragment_place, visibility=VISIBLE, width=1080, height=1479, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.widget.LinearLayout$LayoutParams@e5a94e6, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=252.0, child-count=4}
|
+----->TextView{id=2131165245, res-name=fragment_textview_one, visibility=VISIBLE, width=479, height=100, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.support.constraint.ConstraintLayout$LayoutParams@5d3aa27, tag=null, root-is-layout-requested=false, has-input-connection=false, x=301.0, y=690.0, text=First Fragment, input-type=0, ime-target=false, has-links=false} ****MATCHES****
|
+----->Button{id=2131165242, res-name=fragment_button_one, visibility=VISIBLE, width=286, height=126, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=true, is-enabled=true, is-focused=false, is-focusable=true, is-layout-requested=false, is-selected=false, layout-params=android.support.constraint.ConstraintLayout$LayoutParams@a2184d4, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, text=Button One, input-type=0, ime-target=false, has-links=false}
|
+----->ConstraintLayout{id=-1, visibility=VISIBLE, width=1080, height=1479, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.support.constraint.ConstraintLayout$LayoutParams@bab1972, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=2}
|
+------>TextView{id=2131165245, res-name=fragment_textview_one, visibility=VISIBLE, width=479, height=100, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.support.constraint.ConstraintLayout$LayoutParams@9c6c1c3, tag=null, root-is-layout-requested=false, has-input-connection=false, x=301.0, y=690.0, text=First Fragment, input-type=0, ime-target=false, has-links=false} ****MATCHES****
|
+------>Button{id=2131165242, res-name=fragment_button_one, visibility=VISIBLE, width=286, height=126, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=true, is-enabled=true, is-focused=false, is-focusable=true, is-layout-requested=false, is-selected=false, layout-params=android.support.constraint.ConstraintLayout$LayoutParams@87c1a40, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, text=Button One, input-type=0, ime-target=false, has-links=false}
|
+----->ConstraintLayout{id=-1, visibility=VISIBLE, width=1080, height=1479, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.support.constraint.ConstraintLayout$LayoutParams@30d5abe, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=2}
|
+------>TextView{id=2131165245, res-name=fragment_textview_one, visibility=VISIBLE, width=479, height=100, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.support.constraint.ConstraintLayout$LayoutParams@b49b71f, tag=null, root-is-layout-requested=false, has-input-connection=false, x=301.0, y=690.0, text=First Fragment, input-type=0, ime-target=false, has-links=false} ****MATCHES****
|
+------>Button{id=2131165242, res-name=fragment_button_one, visibility=VISIBLE, width=286, height=126, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=true, is-enabled=true, is-focused=false, is-focusable=true, is-layout-requested=false, is-selected=false, layout-params=android.support.constraint.ConstraintLayout$LayoutParams@5289a6c, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, text=Button One, input-type=0, ime-target=false, has-links=false}
|
+->View{id=16908336, res-name=navigationBarBackground, visibility=VISIBLE, width=1080, height=126, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.widget.FrameLayout$LayoutParams@cded835, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=1794.0}
|
+->View{id=16908335, res-name=statusBarBackground, visibility=VISIBLE, width=1080, height=63, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.widget.FrameLayout$LayoutParams@ec064ca, tag=null, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0}
|
at dalvik.system.VMStack.getThreadStackTrace(Native Method)
at java.lang.Thread.getStackTrace(Thread.java:1538)
at android.support.test.espresso.base.DefaultFailureHandler.getUserFriendlyError(DefaultFailureHandler.java:88)
at android.support.test.espresso.base.DefaultFailureHandler.handle(DefaultFailureHandler.java:51)
at android.support.test.espresso.ViewInteraction.waitForAndHandleInteractionResults(ViewInteraction.java:312)
at android.support.test.espresso.ViewInteraction.check(ViewInteraction.java:297)
at com.example.admin1.espressotestingsample.FragmentTest.testSecondFragment(FragmentTest.java:67)
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 android.support.test.internal.runner.junit4.statement.RunBefores.evaluate(RunBefores.java:80)...

I am confused. First code is working. But second code is not working. Please let me know the reason and help me to test the fragments. Because my entire project build with fragments only.

Solution

Your test throws AmbigousViewMatcherException because it finds 3 of the same matcher withId(R.id.fragment_textview_one), withEffectiveVisibility(VISIBLE)), that means 3 of FragmentOne were created.

In your activity XML layout, change the fragment in the following:

<fragment
    android:name="com.example.admin1.espressotestingsample.fragment.FragmentOne"
    android:id="@+id/fragment_place"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

To other types of ViewGroup, say a FrameLayout:

<FrameLayout
    android:name="com.example.admin1.espressotestingsample.fragment.FragmentOne"
    android:id="@+id/fragment_place"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

I'm not sure about the third fragment, but you shouldn't need to call testRule.getActivity().getSupportFragmentManager().beginTransaction() especially when you're not doing anything with it in your test.

Answered By - Aaron