Working With the REPL Overview Starting the REPL

Working With the REPL
Overview
One of the important tools in creating UITests is the the REPL (read-eval-print-loop). The REPL is a
console-like environment in which the developer enters expressions or a commands. It will then evaluate
those expressions, and display the results to the user.
The REPL is helpful when creating UITests – it allows us to explore the user interface and create the
queries and statements so that the test may interact with the application.
Starting the REPL
The REPL can only be started by running a test which calls the IApp.Repl() method:
[TestFixture]
public class Tests
{
AndroidApp app;
[SetUp]
public void BeforeEachTest()
{
app = ConfigureApp.Android.StartApp();
}
[Test]
public void CreditCardNumber_TooShort_DisplayErrorMessage()
{
app.Repl();
}
}
When the test is run and .Repl() is invoked, UITest will halt the test and start the REPL in a terminal
window:
There are three ways to exit the REPL:
Pressing Ctrl-C
Typing exit
Typing quit
UITest will resume executing the rest of the test when the REPL is closed.
Using the REPL
The REPL provides an instance of IApp that will allow interaction with the application. The REPL also
provides two commands that are useful for creating UITests, the tree command and the copy command.
A common workflow is to use the tree command or IApp.Flash to identify views on the screen and to
obtain meta-data about those views. That information is used to to create AppQueries and spike out the
steps that will make up a test. Then the copy command can be used to copy that work to the clipboard so
that it may be pasted into the test.
Discovering Views With the tree Command
The tree command will display a hierarchical list of the views that are visible on the screen:
Discovering Views with IApp.Flash
Many of the UITest API's take an AppQuery object to locate views on the screen. The IApp.Flash()
method can be very helpful in testing these queries in the REPL. IApp.Flash() will highlight the results
of the query by making them flash, and return some details about the views in the results.
As an example, the following snippet shows how we can locate all of the EditText views that are visible
on an Android activity:
>>> app.Flash(c=>c.Class("EditText"))
Flashing query for Class("EditText") gave 1 results.
[
{
"Id": "creditCardNumberText",
"Description": "android.widget.EditText{528165e4 VFED..CL .F...... 139,70941,178 #7f050001 app:id/creditCardNumberText}",
"Rect": {
"Width": 802.0,
"Height": 108.0,
"X": 139.0,
"Y": 274.0,
"CenterX": 540.0,
"CenterY": 328.0
},
"Label": null,
"Text": "",
"Class": "android.widget.EditText",
"Enabled": true
}
]
We can use the Flash method to help create AppQuerys to use in conjunction with the other APIs to work
out a test.
Creating Steps in a Test
Let's see how we can use the REPL to quickly test out individual steps in a test without having to compile
the application, deploy it to a device/simulator/emulator, and then run the application – a very time
consuming process.
As an example, we can use the results of the tree command above. If our test is required to enter text in
the EditText with the ID of creditCardNumberText, it could use the IApp.EnterText method:
>>> app.EnterText(c=>c.Marked("creditCardNumberText"), "1234567890123456")
Using element matching Marked("creditCardNumberText").
Tapping coordinates [ 540, 328 ].
Likewise, if the test needs to simulate the user tapping on a button, it could use the IApp.Tap method:
>>> app.Tap(c=>c.Marked("validateButton"))
Using element matching Marked("validateButton").
Tapping coordinates [ 540, 533 ].
Using the copy Command
The REPL will keep a history of the commands that you have entered into it during the session. The copy
command paste those commands into the clipboard:
>>> copy
Copying history to clipboard.
This allows you to test out and debug commands in the REPL, and then promptly update your test code.
Summary
In this guide we discussed how to use the REPL to help create UITests. We discussed how to start and
stop the REPL, Other th and how to build out the steps that make up a UITest.