Unit testing for Qt Quick

I am very new to Qt and Qt Quick. I am validating the Qt Test unit testing framework for Qt Quick and I am not able to understand how to run the tests. Here's what I have, I have created a SUBDIRS project with the following structure:

ProjectSolution
   ProjectSolution.pro
   Project
      Project.pro
      Sources/main.cpp
      Resources/qml.qrc/main.qml
   ProjectTest
      ProjectTest.pro
      Sources/main.cpp
      Resources/qml.qrc/main.qml
      Resources/qml.qrc/tst_gui.qml

"Project" is the application to be tested and my test cases are in "ProjectTest/Resources/qml.qrc/tst_gui.qml".

tst_gui.qml:

import QtQuick 2.5
import QtTest 1.0

TestCase {
    name: "UI Testcase"
    when: windowShown

function test_button_click() {
    mouseClick(click_button, Qt.LeftButton, Qt.NoModifier)
}

function test_key_press() {
    keyClick(Qt.Key_Left)
    keyClick("a")
    }
}

I have a Button with id "click_button" in "Project/Resources/qml.qrc/main.qml" that I want to simulate. When I run the test project, I get failure with message:

FAIL!  : tst_gui::UI Testcase::test_button_click() Uncaught exception: click_button is not defined
C:\Users\sjayaprakash\Qt Test Projects\Qt Test Validation\QtTestValidation6\QtTestValidation6Test\tst_gui.qml(9) : failure location

I am sure I am doing something wrong. Could someone please help?

Solution

Finally, I was able to make it work. The test case was not able to find the button since it was in a different QML file. I tried importing and using property alias, both didn't work. I copied everything to my tst_gui.qml (leaving my main.qml empty) and it works fine now.

tst_gui.qml (updated):

import QtTest 1.0
import QtQuick 2.5
import QtQuick.Window 2.0
import QtQuick.Controls 1.4
import QtQuick.Controls.Styles 1.4
import QtQuick.Dialogs 1.2
import QtQml 2.2


Rectangle {
    id: main_window
    visible: true
    width: Screen.width/2
    height: Screen.height/2
    color: "light grey"

    Rectangle {

        property alias click_button: click_button

        id: click_button
        width: main_window.width/4
        height: main_window.height/14
        color: "blue"
        x: main_window.width/2 - click_button.width/2
        y: main_window.height/2 - main_window.height/4
        Text {
            id: button_text
            text: qsTr("Click!")
            font.pointSize: 24
            color: "white"
            anchors.horizontalCenter: parent.horizontalCenter
            anchors.verticalCenter: parent.verticalCenter
        }

        MouseArea {
            anchors.fill: parent
            onClicked: {
                //Log to console as a proof of button click simulation
                console.log("Button was clicked!")
            }
        }
    }

    TextArea {
        id: textarea
        width: main_window.width/2
        height: main_window.height/8
        x: main_window.width/2 - textarea.width/2
        y: (main_window.height/2 - textarea.height/2) + main_window.height/8

        focus: true
        selectByKeyboard: true
        textColor: "darkblue"
        textFormat: TextEdit.PlainText
        wrapMode: TextEdit.WrapAtWordBoundaryOrAnywhere

        Keys.onLeftPressed: {
            //Log to console as a proof of key press simulation
            console.log("Left key was pressed!")
        }
    }


    TestCase {
        name: "UI Testcase"
        when: windowShown

        function test_button_click() {
            mouseClick(click_button, Qt.LeftButton, Qt.NoModifier)
        }

        function test_key_press() {
            keyClick(Qt.Key_Left)
        }
    }
}

In my main.cpp, I am just calling the macro:

QUICK_TEST_MAIN("tst_gui")

Probably, the right way to write unit tests is to separate them from actual code. For now, this works for me.