How to test TextInputLayout values (hint, error, etc.) using Android Espresso?

Here's my custom matcher:

public static Matcher<View> hasTextInputLayoutHintText(final String expectedErrorText) {
        return new TypeSafeMatcher<View>() {

            @Override
            public boolean matchesSafely(View view) {
                if (!(view instanceof TextInputLayout)) {
                    return false;
                }

                CharSequence error = ((TextInputLayout) view).getHint();

                if (error == null) {
                    return false;
                }

                String hint = error.toString();

                return expectedErrorText.equals(hint);
            }

            @Override
            public void describeTo(Description description) {
            }
        };
    }
}

and here's how to use:

@RunWith(AndroidJUnit4.class)
public class MainActivityTest {

    @Rule
    public ActivityTestRule<MainActivity> mRule = new ActivityTestRule<>(MainActivity.class);

    @Test
    public void testMyApp() {
        onView(withId(R.id.textInputLayout)).check
                (matches(hasTextInputLayoutErrorText(mRule.getActivity().getString(R.string
                        .app_name))));

    }

If you would like to check errorText of TextInputLayout, change this line:

     CharSequence error = ((TextInputLayout) view).getHint();

with

     CharSequence error = ((TextInputLayout) view).getError();

Hope it will help

Kotlin version of piotrek1543's answer:

fun hasTextInputLayoutHintText(expectedErrorText: String): Matcher<View> = object : TypeSafeMatcher<View>() {

    override fun describeTo(description: Description?) { }

    override fun matchesSafely(item: View?): Boolean {
        if (item !is TextInputLayout) return false
        val error = item.hint ?: return false
        val hint = error.toString()
        return expectedErrorText == hint
    }
}