Mock plt.subplots which has multiple outputs

pytest_plt/plugin.py

@@ -58,6 +58,8 @@ def pytest_report_teststatus(report):
 
 
 class Mock:
+    multi_functions = {}
+
     def __init__(self, *args, **kwargs):
         pass
 
@@ -81,10 +83,16 @@ def __getattr__(cls, name):
             mockType = type(name, (), {})
             mockType.__module__ = __name__
             return mockType
+        elif name in cls.multi_functions:
+            return lambda *args, **kwargs: tuple(Mock() for _ in range(cls.multi_functions[name]))
         else:
             return Mock()
 
 
+class PltMock(Mock):
+    multi_functions = {"subplots": 2}
+
+
 class Recorder:
     def __init__(self, dirname, nodeid, filename_drop=None):
         self.dirname = dirname
@@ -139,7 +147,7 @@ def __enter__(self):
         if self.record:
             self.plt = mpl_plt
         else:
-            self.plt = Mock()
+            self.plt = PltMock()
         self.plt.saveas = self.get_filename(ext="pdf")
         return self.plt
 
@@ -174,8 +182,7 @@ def save(self, path):
 
 @pytest.fixture
 def plt(request):
-    """
-    A pyplot-compatible plotting interface.
+    """A pyplot-compatible plotting interface.
 
     Use this to create plots in your tests using the ``matplotlib.pyplot``
     interface.
@@ -210,4 +217,4 @@ def _finalize():
             request.node.user_properties.append(("plt_saved", plotter.saved))
 
     request.addfinalizer(_finalize)
-    return plotter.__enter__()  # pylint: disable=unnecessary-dunder-call
+    return plotter.__enter__()

pytest_plt/tests/test_plt.py

@@ -31,6 +31,13 @@ def test_mock_iter(plt):
     plt.saveas = None
 
 
+def test_mock_subplots(plt):
+    fig, axes = plt.subplots(2, 1)
+    axes[0].plot(np.arange(10))
+    axes[1].plot(-np.arange(10))
+    fig.tight_layout()
+
+
 def test_simple_plot(plt):
     plt.plot(np.linspace(0, 1, 20), np.linspace(0, 2, 20))
 

setup.py

@@ -40,7 +40,9 @@ def read(*filenames, **kwargs):
     "sphinx",
 ]
 optional_req = []
-tests_req = []
+tests_req = [
+    "pytest-cov",  # required since `addopts = --cov` in setup.cfg
+]
 
 setup(
     name="pytest-plt",