Click home icon with Espresso

I found a real solution to this issue. By using the hierarchyviewer I found that the toolbar looks like this:

This means we could match the hamburger icon (not back button) like this:

onView(withContentDescription("Open navigation")).perform(click());

But a better solution to me was to find out that the hamburger icon is the only ImageButton and a direct child view of the v7 Toolbar. So I wrote a helper method to match it:

public static Matcher<View> androidHomeMatcher() {
    return allOf(
        withParent(withClassName(is(Toolbar.class.getName()))),
        withClassName(anyOf(
            is(ImageButton.class.getName()),
            is(AppCompatImageButton.class.getName())
    )));
}

@Test
public void clickHamburgerIcon() throws Exception {
    onView(androidHomeMatcher()).perform(click());
    // ...
}

This solution is better because it should match the view no matter which locale you use in your test. :-)

EDIT: Note that Toolbar might be android.support.v7.widget.Toolbar or android.widget.Toolbar - depending on your use case!

EDIT: The support lib version 24.2.0 uses AppCompatImageButton instead of ImageButton, so I added it, too.

EDIT: You have to import the correct methods to get this to work. Here are the imports used:

import static android.support.test.espresso.matcher.ViewMatchers.withClassName;
import static android.support.test.espresso.matcher.ViewMatchers.withParent;
import static org.hamcrest.Matchers.allOf;
import static org.hamcrest.Matchers.is;

To not depend on the app locale, you can use the code from Matt Logan by replacing "Navigate up" with R.string.abc_action_bar_up_description:

onView(withContentDescription(R.string.abc_action_bar_up_description)).perform(click());

This helped me a lot because I have an app in more than 5 languages and I had to act like this.

Use the withContentDescription() Matcher:

onView(withContentDescription("Navigate up")).perform(click());

I had trouble navigating back from one Activity to another, but then I found top-level actions:

Espresso.pressBack();