Testing: Test that "%matplotlib qt" is working

spyder_kernels/ipdb/tests/test_matplotlib.py

@@ -45,3 +45,33 @@ def test_matplotlib_inline(qtconsole, qtbot):
 
     # Assert that there's a plot in the console
     assert shell._control.toHtml().count('img src') == 1
+
+
+def test_matplotlib_qt(qtconsole, qtbot):
+    """Test that %matplotlib qt is working."""
+    window = qtconsole.window
+    shell = window.active_frontend
+
+    # Wait until the console is fully up
+    qtbot.waitUntil(lambda: shell._prompt_html is not None,
+                    timeout=SHELL_TIMEOUT)
+
+    # Set qt backend
+    with qtbot.waitSignal(shell.executed):
+        shell.execute("%matplotlib qt")
+
+    # Make a plot
+    with qtbot.waitSignal(shell.executed):
+        shell.execute("import matplotlib.pyplot as plt; plt.plot(range(10))")
+
+    # Assert we have three prompts in the console, meaning that the
+    # previous plot command was non-blocking
+    assert '3' in shell._prompt_html
+
+    # Running QApplication.instance() should return a QApplication
+    # object because "%matplotlib qt" creates one
+    with qtbot.waitSignal(shell.executed):
+        shell.execute("from PyQt5.QtWidgets import QApplication; QApplication.instance()")
+
+    # Assert the previous command returns the object
+    assert 'PyQt5.QtWidgets.QApplication object' in shell._control.toPlainText()