On this page:
28.1 Actions and completeness
28.2 Errors
28.3 Technical Issues
28.3.1 Active Frame
28.3.2 Thread Issues
28.3.3 Window Manager (Unix only)
28.4 Test Functions
test: button-push
test: set-radio-box!
test: set-radio-box-item!
test: set-check-box!
test: set-choice!
test: set-list-box!
test: keystroke
test: menu-select
test: mouse-click
test: run-interval
test: current-get-eventspaces
test: new-window
test: close-top-level-window
test: top-level-focus-window-has?
test: number-pending-actions
test: reraise-error
test: run-one

28 Test

 (require framework/test)

The framework provides several new primitive functions that simulate user actions, which may be used to test applications. You use these primitives and combine them just as regular Racket functions. For example,
  (test:keystroke #\A)
  (test:menu-select "File" "Save")
sends a keystroke event to the window with the keyboard focus and invokes the callback function for the “Save” menu item from the “File” menu. This has the same effect as if the user typed the key “A”, pulled down the “File” menu and selected “Save”.

It is possible to load this portion of the framework without loading the rest of the framework. Use (require framework/test).

Currently, the test engine has primitives for pushing buttons, setting check-boxes and choices, sending keystrokes, selecting menu items and clicking the mouse. Many functions that are also useful in application testing, such as traversing a tree of panels, getting the text from a canvas, determining if a window is shown, and so on, exist in GRacket.

28.1 Actions and completeness

The actions associated with a testing primitive may not have finished when the primitive returns to its caller. Some actions may yield control before they can complete. For example, selecting “Save As...” from the “File” menu opens a dialog box and will not complete until the “OK” or “Cancel” button is pushed.

However, all testing functions wait at least a minimum interval before returning to give the action a chance to finish. This interval controls the speed at which the test suite runs, and gives some slack time for events to complete. The default interval is 100 milliseconds. The interval can be queried or set with test:run-interval.

A primitive action will not return until the run-interval has expired and the action has finished, raised an error, or yielded. The number of incomplete actions is given by test:number-pending-actions.

Note: Once a primitive action is started, it is not possible to undo it or kill its remaining effect. Thus, it is not possible to write a utility that flushes the incomplete actions and resets number-pending-actions to zero.

However, actions which do not complete right away often provide a way to cancel themselves. For example, many dialog boxes have a “Cancel” button which will terminate the action with no further effect. But this is accomplished by sending an additional action (the button push), not by undoing the original action.

28.2 Errors

Errors in the primitive actions (which necessarily run in the handler thread) are caught and reraised in the calling thread.

However, the primitive actions can only guarantee that the action has started, and they may return before the action has completed. As a consequence, an action may raise an error long after the function that started it has returned. In this case, the error is saved and reraised at the first opportunity (the next primitive action).

The test engine keeps a buffer for one error, saving only the first error. Any subsequent errors are discarded. Reraising an error empties the buffer, allowing the next error to be saved.

The function test:reraise-error reraises any pending errors.

28.3 Technical Issues

28.3.1 Active Frame

The Self Test primitive actions all implicitly apply to the top-most (active) frame.

28.3.2 Thread Issues

The code started by the primitive actions must run in the handler thread of the eventspace where the event takes place. As a result, the test suite that invokes the primitive actions must not run in that handler thread (or else some actions will deadlock). See make-eventspace for more info.

28.3.3 Window Manager (Unix only)

In order for the Self Tester to work correctly, the window manager must set the keyboard focus to follow the active frame. This is the default behavior in Microsoft Windows and MacOS, but not in X windows.

In X windows, you must explicitly tell your window manager to set the keyboard focus to the top-most frame, regardless of the position of the actual mouse.

28.4 Test Functions

(test:button-push button)  void?
  button : 
(or/c (λ (str)
        (and (string? str)
             (test:top-level-focus-window-has?
              (λ (c)
                (and (is-a? c button%)
                     (string=? (send c get-label) str)
                     (send c is-enabled?)
                     (send c is-shown?))))))
 
      (and/c (is-a?/c button%)
             (λ (btn)
               (and (send btn is-enabled?)
                    (send btn is-shown?)))
             (λ (btn)
               (test:top-level-focus-window-has?
                (λ (c) (eq? c btn))))))
Simulates pushing button. If a string is supplied, the primitive searches for a button labelled with that string in the active frame. Otherwise, it pushes the button argument.
(test:set-radio-box! radio-box state)  void?
  radio-box : (or/c string? (is-a?/c radio-box%))
  state : (or/c string? number?)
Sets the radio-box to state. If state is a string, this function finds the choice with that label and if it is a number, it uses the number as an index into the state. If the number is out of range or if the label isn’t in the radio box, an exception is raised.

If radio-box is a string, this function searches for a radio-box% object with a label matching that string, otherwise it uses radio-box itself.
(test:set-radio-box-item! entry)  void?
  entry : string?
Finds a radio-box% that has a label entry and sets the radio-box to entry.
(test:set-check-box! check-box state)  void?
  check-box : (or/c string? (is-a?/c check-box%))
  state : boolean?
Clears the check-box% item if state is #f, and sets it otherwise.

If check-box is a string, this function searches for a check-box% with a label matching that string, otherwise it uses check-box itself.
(test:set-choice! choice str)  void?
  choice : (or/c string? (is-a?/c choice%))
  str : (or/c string? (and/c number? exact? integer? positive?))
Selects choice’s item str. If choice is a string, this function searches for a choice% with a label matching that string, otherwise it uses choice itself.
(test:set-list-box! choice str)  void?
  choice : (or/c string? (is-a?/c list-box%))
  str : (or/c string? (and/c number? exact? integer? positive?))
Selects list-box’s item str. If list-box is a string, this function searches for a list-box% with a label matching that string, otherwise it uses list-box itself.
(test:keystroke key [modifier-list])  void?
  key : (or/c char? symbol?)
  modifier-list : (listof (symbols 'alt 'control 'meta 'shift 'noalt 'nocontrol 'nometea 'noshift))
   = null
This function simulates a user pressing a key. The argument, key, is just like the argument to the get-key-code method of the key-event% class.

Note: To send the “Enter” key, use #\return, not #\newline.

The 'shift or 'noshift modifier is implicitly set from key, but is overridden by the argument list. The 'shift modifier is set for any capitol alpha-numeric letters and any of the following characters:
  #\? #\: #\~ #\\ #\|
  #\< #\> #\{ #\} #\[ #\] #\( #\)
  #\! #\@ #\# #\$ #\% #\^ #\& #\* #\_ #\+

If conflicting modifiers are provided, the ones later in the list are used.
(test:menu-select menu item)  void?
  menu : string?
  item : string?
Selects the menu-item named item in the menu named menu.

Note: The string for the menu item does not include its keyboard equivalent. For example, to select “New” from the “File” menu, use “New”, not “New Ctrl+m n”.
(test:mouse-click button x y [modifiers])  void?
  button : (symbols 'left 'middle 'right)
  x : (and/c exact? integer?)
  y : (and/c exact? integer?)
  modifiers : (listof (symbols 'alt 'control 'meta 'shift 'noalt 'nocontrol 'nometa 'noshift))
   = null
Simulates a mouse click at the coordinate (x,y) in the currently focused window, assuming that it supports the on-event method. Use test:button-push to click on a button.

On the Macintosh, 'right corresponds to holding down the command modifier key while clicking and 'middle cannot be generated.

Under Windows, 'middle can only be generated if the user has a three button mouse.

The modifiers later in the list modifiers take precedence over ones that appear earlier.
(test:run-interval msec)  void?
  msec : number?
(test:run-interval)  number?
See also Actions and completeness. The first case in the case-lambda sets the run interval to msec milliseconds and the second returns the current setting.
This parameter that specifies which evenspaces (see also Event Dispatching and Eventspaces) are considered when finding the frontmost frame. The first case sets the parameter to func. The procedure func will be invoked with no arguments to determine the eventspaces to consider when finding the frontmost frame for simulated user events. The second case returns the current value of the parameter. This will be a procedure which, when invoked, returns a list of eventspaces.
(test:new-window window)  void?
  window : (is-a?/c window<%>)
Moves the keyboard focus to a new window within the currently active frame. Unfortunately, neither this function nor any other function in the test engine can cause the focus to move from the top-most (active) frame.
Use this function to simulate clicking on the close box of a frame. Closes tlw with this expression:
  (when (send tlw can-close?)
    (send tlw on-close)
    (send tlw show #f))
Calls test for each child of the top-level-focus-frame and returns #t if test ever does, otherwise returns #f. If there is no top-level-focus-window, returns #f.
Returns the number of pending events (those that haven’t completed yet)
See also Errors.
(test:run-one f)  void?
  f : (-> void?)
Runs the function f as if it was a simulated event.