How do you get view hierarchy in Android or Android Espresso

Issue

I am using Android Espresso and when it cannot find a match, it will throw an exception with printing the view hierarchy. Is there a way to get this kind of view hierarchy dynamically when you are running Android testing or Espresso

View Hierarchy:
+>DecorView{id=-1, visibility=VISIBLE, width=480, height=800,     has-focus=true, 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, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=2}
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+->LinearLayout{id=-1, visibility=VISIBLE, width=480, height=800, has-focus=true, 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, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=2}
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+-->ViewStub{id=16909225, 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, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0}
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+-->FrameLayout{id=-1, visibility=VISIBLE, width=480, height=764, has-focus=true, 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, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=36.0, child-count=1}
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+--->ActionBarOverlayLayout{id=2131427395, res-name=decor_content_parent, visibility=VISIBLE, width=480, height=764, has-focus=true, 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, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=2}
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Solution

Given Android View hierarchy is a tree structure and it is easier to iterate through each tree node using some sort of algorithms, you can view those method at https://developer.android.com/reference/android/support/test/espresso/util/TreeIterables.html

The way it prints out the Exception trace uses a method called breadthFirstViewTraversaland print out view tree in class ViewFinderImpl https://developer.android.com/reference/android/support/test/espresso/base/ViewFinderImpl.html

Answered By - WenChao