Some time ago, due to work needs, I studied some things about automated testing, including Espresso provided by Android, and the third-party cross-platform Appium. Both of these focus on UI testing, and functional or unit tests still need to be written with other tools.

I basically read through the official documents provided by Espresso, including UI Automator. Espresso can basically meet the needs of business process testing of a single APP (of course UI-oriented testing), and UI Automator (and Appium) has good support for cross-APP testing.

I am currently writing a series of articles on automated testing, which can be viewed on my homepage for reference~ There are indeed very few reference materials in this area, and I hope we can communicate more~

Since no one has answered, I can only answer my progress myself.
There are still many in-depth functions that have not been explored, but as far as my question mentioned, verifying the accuracy of the data. Because I have not found an operation that can simulate a very important operation in human operations, which is "observation & recording". In other words, I don't know how to get the Text content in a TextView I found. If you know this step, you can record some data and compare it. The following is a solution I found that can getText().

String getText(final Matcher<View> matcher) {
    final String[] stringHolder = { null };
    onView(matcher).perform(new ViewAction() {
        @Override
        public Matcher<View> getConstraints() {
            return isAssignableFrom(TextView.class);
        }

        @Override
        public String getDescription() {
            return "getting text from a TextView";
        }

        @Override
        public void perform(UiController uiController, View view) {
            TextView tv = (TextView)view; //Save, because of check in getConstraints()
            stringHolder[0] = tv.getText().toString();
        }
    });
    return stringHolder[0];
}

Code excerpted from: http://stackoverflow.com/questions/23381459/how-to-get-text-from-textview-using-espresso