ui-tests: move code to wait for text in the Windows Terminal into a function

This code is way too useful _not_ to make it reusable.

While at it, improve on the timeout logic to be quite a bit more
precise.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

ui-tests/background-hook.ahk

@@ -38,14 +38,7 @@ Send('git config user.name Test{Enter}git config user.email [email protected]{Enter}')
 Info('Committing')
 Send('git commit --allow-empty -m zOMG{Enter}')
 ; Wait for the hook to finish printing
-While not RegExMatch(CaptureTextFromWindowsTerminal(), '`n49$')
-{
-    Sleep 100
-    if A_Index > 1000
-        ExitWithError 'Timed out waiting for commit to finish'
-    MouseClick 'WheelDown', , , 20
-}
-Info('Hook finished')
+WaitForRegExInWindowsTerminal('`n49$', 'Timed out waiting for commit to finish', 'Hook finished', 100000)
 
 ; Verify that CursorUp shows the previous command
 Send('{Up}')

ui-tests/ui-test-library.ahk

@@ -81,4 +81,17 @@ CaptureTextFromWindowsTerminal() {
     Result := A_Clipboard
     Clipboard := SavedClipboard
     return Result
+}
+
+WaitForRegExInWindowsTerminal(regex, errorMessage, successMessage, timeout := 5000) {
+    timeout := timeout + A_TickCount
+    ; Wait for the regex to match in the terminal output
+    while not RegExMatch(CaptureTextFromWindowsTerminal(), regex)
+    {
+        Sleep 100
+        if A_TickCount > timeout
+            ExitWithError errorMessage
+        MouseClick 'WheelDown', , , 20
+    }
+    Info(successMessage)
 }