Android testing. Espresso. Change text in a TextView

You can look into implementing your own ViewAction.

Here is the modified version of the replaceText viewaction from espresso library that is meant to work on the TextView.

 public static ViewAction setTextInTextView(final String value){
            return new ViewAction() {
                @SuppressWarnings("unchecked")
                @Override
                public Matcher<View> getConstraints() {
                    return allOf(isDisplayed(), isAssignableFrom(TextView.class));
                }

                @Override
                public void perform(UiController uiController, View view) {
                    ((TextView) view).setText(value);
                }

                @Override
                public String getDescription() {
                    return "replace text";
                }
            };
    }