TestCase QML Type

Qt 5.7.1 Reference Documentation

TestCase QML Type

Represents a unit test case More...

Import Statement:	import QtTest 1.1
Since:	Qt 4.8
Inherits:	Item

List of all members, including inherited members

Properties

completed : bool
name : string
optional : bool
running : bool
when : bool
windowShown : bool

Methods

cleanup()
cleanupTestCase()
compare(actual, expected, message)
expectFail(tag, message)
expectFailContinue(tag, message)
fail(message)
QtObject findChild(parent, objectName)
fuzzyCompare(actual, expected, delta, message)
object grabImage(item)
ignoreWarning(message)
init()
initTestCase()
keyClick(key, modifiers, delay)
keyPress(key, modifiers, delay)
keyRelease(key, modifiers, delay)
mouseClick(item, x, y, button, modifiers, delay)
mouseDoubleClick(item, x, y, button, modifiers, delay)
mouseDoubleClickSequence(item, x, y, button, modifiers, delay)
mouseDrag(item, x, y, dx, dy, button, modifiers, delay)
mouseMove(item, x, y, delay)
mousePress(item, x, y, button, modifiers, delay)
mouseRelease(item, x, y, button, modifiers, delay)
mouseWheel(item, x, y, xDelta, yDelta, button, modifiers, delay)
skip(message)
sleep(ms)
tryCompare(obj, property, expected, timeout, message)
verify(condition, message)
wait(ms)
waitForRendering(item, timeout)
warn(message)

Detailed Description

Introduction to QML test cases

Test cases are written as JavaScript functions within a TestCase type:


  import QtQuick 2.0
  import QtTest 1.0

  TestCase {
      name: "MathTests"

      function test_math() {
          compare(2 + 2, 4, "2 + 2 = 4")
      }

      function test_fail() {
          compare(2 + 2, 5, "2 + 2 = 5")
      }
  }

Functions whose names start with "test_" are treated as test cases to be executed. The name property is used to prefix the functions in the output:


  ********* Start testing of MathTests *********
  Config: Using QTest library 4.7.2, Qt 4.7.2
  PASS   : MathTests::initTestCase()
  FAIL!  : MathTests::test_fail() 2 + 2 = 5
     Actual (): 4
     Expected (): 5
     Loc: [/home/.../tst_math.qml(12)]
  PASS   : MathTests::test_math()
  PASS   : MathTests::cleanupTestCase()
  Totals: 3 passed, 1 failed, 0 skipped
  ********* Finished testing of MathTests *********

Because of the way JavaScript properties work, the order in which the test functions are found is unpredictable. To assist with predictability, the test framework will sort the functions on ascending order of name. This can help when there are two tests that must be run in order.

Multiple TestCase types can be supplied. The test program will exit once they have all completed. If a test case doesn't need to run (because a precondition has failed), then optional can be set to true.

Data-driven tests

Table data can be provided to a test using a function name that ends with "_data". Alternatively, the init_data() function can be used to provide default test data for all test functions in a TestCase type:


  import QtQuick 2.0
  import QtTest 1.1

  TestCase {
      name: "DataTests"

      function init_data() {
        return [
             {tag:"init_data_1", a:1, b:2, answer: 3},
             {tag:"init_data_2", a:2, b:4, answer: 6}
        ];
      }

      function test_table_data() {
          return [
              {tag: "2 + 2 = 4", a: 2, b: 2, answer: 4 },
              {tag: "2 + 6 = 8", a: 2, b: 6, answer: 8 },
          ]
      }

      function test_table(data) {
          //data comes from test_table_data
          compare(data.a + data.b, data.answer)
      }

      function test__default_table(data) {
          //data comes from init_data
          compare(data.a + data.b, data.answer)
      }
  }

The test framework will iterate over all of the rows in the table and pass each row to the test function. As shown, the columns can be extracted for use in the test. The tag column is special - it is printed by the test framework when a row fails, to help the reader identify which case failed amongst a set of otherwise passing tests.

Benchmarks

Functions whose names start with "benchmark_" will be run multiple times with the Qt benchmark framework, with an average timing value reported for the runs. This is equivalent to using the QBENCHMARK macro in the C++ version of QTestLib.


  TestCase {
      id: top
      name: "CreateBenchmark"

      function benchmark_create_component() {
          var component = Qt.createComponent("item.qml")
          var obj = component.createObject(top)
          obj.destroy()
          component.destroy()
      }
  }

  RESULT : CreateBenchmark::benchmark_create_component:
       0.23 msecs per iteration (total: 60, iterations: 256)
  PASS   : CreateBenchmark::benchmark_create_component()

To get the effect of the QBENCHMARK_ONCE macro, prefix the test function name with "benchmark_once_".

Simulating keyboard and mouse events

The keyPress(), keyRelease(), and keyClick() methods can be used to simulate keyboard events within unit tests. The events are delivered to the currently focused QML item. You can pass either a Qt.Key enum value or a latin1 char (string of length one)


  Rectangle {
      width: 50; height: 50
      focus: true

      TestCase {
          name: "KeyClick"
          when: windowShown

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

The mousePress(), mouseRelease(), mouseClick(), mouseDoubleClick(), mouseDoubleClickSequence() and mouseMove() methods can be used to simulate mouse events in a similar fashion.

Note: keyboard and mouse events can only be delivered once the main window has been shown. Attempts to deliver events before then will fail. Use the when and windowShown properties to track when the main window has been shown.

Property Documentation

completed : bool

This property will be set to true once the test case has completed execution. Test cases are only executed once. The initial value is false.

See also running and when.

name : string

This property defines the name of the test case for result reporting. The default is the empty string.


  TestCase {
      name: "ButtonTests"
      ...
  }

optional : bool

Multiple TestCase types can be supplied in a test application. The application will exit once they have all completed. If a test case does not need to run (because a precondition has failed), then this property can be set to true. The default value is false.


  TestCase {
      when: false
      optional: true
      function test_not_run() {
          verify(false)
      }
  }

See also when and completed.

running : bool

This property will be set to true while the test case is running. The initial value is false, and the value will become false again once the test case completes.

See also completed and when.

when : bool

This property should be set to true when the application wants the test cases to run. The default value is true. In the following example, a test is run when the user presses the mouse button:


  Rectangle {
      id: foo
      width: 640; height: 480
      color: "cyan"

      MouseArea {
          id: area
          anchors.fill: parent
      }

      property bool bar: true

      TestCase {
          name: "ItemTests"
          when: area.pressed
          id: test1

          function test_bar() {
              verify(bar)
          }
      }
  }

The test application will exit once all TestCase types have been triggered and have run. The optional property can be used to exclude a TestCase type.

See also optional and completed.

windowShown : bool

This property will be set to true after the QML viewing window has been displayed. Normally test cases run as soon as the test application is loaded and before a window is displayed. If the test case involves visual types and behaviors, then it may need to be delayed until after the window is shown.


  Button {
      id: button
      onClicked: text = "Clicked"
      TestCase {
          name: "ClickTest"
          when: windowShown
          function test_click() {
              button.clicked();
              compare(button.text, "Clicked");
          }
      }
  }

Method Documentation

cleanup()

This function is called after each test function that is executed in the TestCase type. The default implementation does nothing. The application can provide its own implementation to perform cleanup after each test function.

See also init() and cleanupTestCase().

cleanupTestCase()

This function is called after all other test functions in the TestCase type have completed. The default implementation does nothing. The application can provide its own implementation to perform test case cleanup.

See also initTestCase() and cleanup().

compare(actual, expected, message = "")

Fails the current test case if actual is not the same as expected, and displays the optional message. Similar to QCOMPARE(actual, expected) in C++.

See also tryCompare() and fuzzyCompare.

expectFail(tag, message)

In a data-driven test, marks the row associated with tag as expected to fail. When the fail occurs, display the message, abort the test, and mark the test as passing. Similar to QEXPECT_FAIL(tag, message, Abort) in C++.

If the test is not data-driven, then tag must be set to the empty string.

See also expectFailContinue().

expectFailContinue(tag, message)

In a data-driven test, marks the row associated with tag as expected to fail. When the fail occurs, display the message, and then continue the test. Similar to QEXPECT_FAIL(tag, message, Continue) in C++.

If the test is not data-driven, then tag must be set to the empty string.

See also expectFail().

fail(message = "")

Fails the current test case, with the optional message. Similar to QFAIL(message) in C++.

QtObject findChild(parent, objectName)

Returns the first child of parent with objectName, or null if no such item exists. Both visual and non-visual children are searched recursively, with visual children being searched first.


  compare(findChild(item, "childObject"), expectedChildObject);

This QML method was introduced in Qt 5.4.

fuzzyCompare(actual, expected, delta, message = "")

Fails the current test case if the difference betwen actual and expected is greater than delta, and displays the optional message. Similar to qFuzzyCompare(actual, expected) in C++ but with a required delta value.

This function can also be used for color comparisons if both the actual and expected values can be converted into color values. If any of the differences for RGBA channel values are greater than delta, the test fails.

See also tryCompare() and compare().

object grabImage(item)

Returns a snapshot image object of the given item.

The returned image object has the following methods:

red(x, y) Returns the red channel value of the pixel at x, y position
green(x, y) Returns the green channel value of the pixel at x, y position
blue(x, y) Returns the blue channel value of the pixel at x, y position
alpha(x, y) Returns the alpha channel value of the pixel at x, y position
pixel(x, y) Returns the color value of the pixel at x, y position

equals(image) Returns true if this image is identical to image - see QImage::operator== (since 5.6)

For example:


  var image = grabImage(rect);
  compare(image.red(10, 10), 255);
  compare(image.pixel(20, 20), Qt.rgba(255, 0, 0, 255));

  rect.width += 10;
  var newImage = grabImage(rect);
  verify(!newImage.equals(image));

ignoreWarning(message)

Marks message as an ignored warning message. When it occurs, the warning will not be printed and the test passes. If the message does not occur, then the test will fail. Similar to QTest::ignoreMessage(QtWarningMsg, message) in C++.

See also warn().

init()

This function is called before each test function that is executed in the TestCase type. The default implementation does nothing. The application can provide its own implementation to perform initialization before each test function.

See also cleanup() and initTestCase().

initTestCase()

This function is called before any other test functions in the TestCase type. The default implementation does nothing. The application can provide its own implementation to perform test case initialization.

See also cleanupTestCase() and init().

keyClick(key, modifiers = Qt.NoModifier, delay = -1)

Simulates clicking of key with an optional modifier on the currently focused item. If delay is larger than 0, the test will wait for delay milliseconds.

The event will be sent to the TestCase window or, in case of multiple windows, to the current active window. See QGuiApplication::focusWindow() for more details.

See also keyPress() and keyRelease().

keyPress(key, modifiers = Qt.NoModifier, delay = -1)

Simulates pressing a key with an optional modifier on the currently focused item. If delay is larger than 0, the test will wait for delay milliseconds.

The event will be sent to the TestCase window or, in case of multiple windows, to the current active window. See QGuiApplication::focusWindow() for more details.

Note: At some point you should release the key using keyRelease().

See also keyRelease() and keyClick().

keyRelease(key, modifiers = Qt.NoModifier, delay = -1)

Simulates releasing a key with an optional modifier on the currently focused item. If delay is larger than 0, the test will wait for delay milliseconds.

The event will be sent to the TestCase window or, in case of multiple windows, to the current active window. See QGuiApplication::focusWindow() for more details.

See also keyPress() and keyClick().

mouseClick(item, x = item.width / 2, y = item.height / 2, button = Qt.LeftButton, modifiers = Qt.NoModifier, delay = -1)

Simulates clicking a mouse button with an optional modifier on an item. The position of the click is defined by x and y. If x and y are not defined the position will be the center of item. If delay is specified, the test will wait for the specified amount of milliseconds before pressing and before releasing the button.

The position given by x and y is transformed from the co-ordinate system of item into window co-ordinates and then delivered. If item is obscured by another item, or a child of item occupies that position, then the event will be delivered to the other item instead.

mouseDoubleClick(item, x = item.width / 2, y = item.height / 2, button = Qt.LeftButton, modifiers = Qt.NoModifier, delay = -1)

Simulates double-clicking a mouse button with an optional modifier on an item. The position of the click is defined by x and y. If x and y are not defined the position will be the center of item. If delay is specified, the test will wait for the specified amount of milliseconds before pressing and before releasing the button.

mouseDoubleClickSequence(item, x = item.width / 2, y = item.height / 2, button = Qt.LeftButton, modifiers = Qt.NoModifier, delay = -1)

Simulates the full sequence of events generated by double-clicking a mouse button with an optional modifier on an item.

This method reproduces the sequence of mouse events generated when a user makes a double click: Press-Release-Press-DoubleClick-Release.

The position of the click is defined by x and y. If x and y are not defined the position will be the center of item. If delay is specified, the test will wait for the specified amount of milliseconds before pressing and before releasing the button.

This QML method was introduced in Qt 5.5.

mouseDrag(item, x, y, dx, dy, button = Qt.LeftButton, modifiers = Qt.NoModifier, delay = -1)

Simulates dragging the mouse on an item with button pressed and an optional modifier. The initial drag position is defined by x and y, and drag distance is defined by dx and dy. If delay is specified, the test will wait for the specified amount of milliseconds before releasing the button.

Note: this method does not imply a drop action, to make a drop, an additional mouseRelease(item, x + dx, y + dy) is needed.

mouseMove(item, x, y, delay = -1)

Moves the mouse pointer to the position given by x and y within item. If a delay (in milliseconds) is given, the test will wait before moving the mouse pointer.

mousePress(item, x = item.width / 2, y = item.height / 2, button = Qt.LeftButton, modifiers = Qt.NoModifier, delay = -1)

Simulates pressing a mouse button with an optional modifier on an item. The position is defined by x and y. If x or y are not defined the position will be the center of item. If delay is specified, the test will wait for the specified amount of milliseconds before the press.

mouseRelease(item, x = item.width / 2, y = item.height / 2, button = Qt.LeftButton, modifiers = Qt.NoModifier, delay = -1)

Simulates releasing a mouse button with an optional modifier on an item. The position of the release is defined by x and y. If x or y are not defined the position will be the center of item. If delay is specified, the test will wait for the specified amount of milliseconds before releasing the button.

mouseWheel(item, x, y, xDelta, yDelta, button = Qt.LeftButton, modifiers = Qt.NoModifier, delay = -1)

Simulates rotating the mouse wheel on an item with button pressed and an optional modifier. The position of the wheel event is defined by x and y. If delay is specified, the test will wait for the specified amount of milliseconds before releasing the button.

The xDelta and yDelta contain the wheel rotation distance in eighths of a degree. see QWheelEvent::angleDelta() for more details.

skip(message = "")

Skips the current test case and prints the optional message. If this is a data-driven test, then only the current row is skipped. Similar to QSKIP(message) in C++.

sleep(ms)

Sleeps for ms milliseconds without processing Qt events.

See also wait() and waitForRendering().

tryCompare(obj, property, expected, timeout = 5000, message = "")

Fails the current test case if the specified property on obj is not the same as expected, and displays the optional message. The test will be retried multiple times until the timeout (in milliseconds) is reached.

This function is intended for testing applications where a property changes value based on asynchronous events. Use compare() for testing synchronous property changes.


  tryCompare(img, "status", BorderImage.Ready)
  compare(img.width, 120)
  compare(img.height, 120)
  compare(img.horizontalTileMode, BorderImage.Stretch)
  compare(img.verticalTileMode, BorderImage.Stretch)

SignalSpy::wait() provides an alternative method to wait for a signal to be emitted.

See also compare() and SignalSpy::wait().

verify(condition, message = "")

Fails the current test case if condition is false, and displays the optional message. Similar to QVERIFY(condition) or QVERIFY2(condition, message) in C++.

wait(ms)

Waits for ms milliseconds while processing Qt events.

See also sleep() and waitForRendering().

waitForRendering(item, timeout = 5000)

Waits for timeout milliseconds or until the item is rendered by the renderer. Returns true if item is rendered in timeout milliseconds, otherwise returns false. The default timeout value is 5000.

See also sleep() and wait().

warn(message)

Prints message as a warning message. Similar to QWARN(message) in C++.

See also ignoreWarning().

Contents

TestCase QML Type

Properties

Methods

Detailed Description

Introduction to QML test cases

Data-driven tests

Benchmarks

Simulating keyboard and mouse events

Property Documentation

Method Documentation