Fix some tests

{{cookiecutter.plugin_name}}/src/{{cookiecutter.module_name}}/_tests/test_widget.py

@@ -1,9 +1,33 @@
 import numpy as np
 
-from {{cookiecutter.module_name}} import ExampleQWidget, example_magic_widget
+from {{cookiecutter.module_name}} import example_function_widget, example_magic_widget, ExampleQWidget
 
 
+
+
+def test_example_function_widget():
+    # because our "widget" is a pure function, we can call it and
+    # test it independently of napari
+    im_data = np.random.random((100, 100))
+    thresholded = example_function_widget(im_data)
+    assert thresholded.shape == im_data.shape
+    # etc.
+
 # make_napari_viewer is a pytest fixture that returns a napari viewer object
+# you don't need to import it, as long as napari is installed 
+# in your testing environment
+def test_example_magic_widget(make_napari_viewer):
+    viewer = make_napari_viewer()
+    layer = viewer.add_image(np.random.random((100, 100)))
+
+    # our widget will be a MagicFactory or FunctionGui instance
+    my_widget = example_magic_widget()
+
+    # if we "call" this object, it'll execute our function
+    thresholded = my_widget(viewer.layers[0], 0.5)
+    assert thresholded.shape == layer.data.shape
+    # etc.
+
 # capsys is a pytest fixture that captures stdout and stderr output streams
 def test_example_q_widget(make_napari_viewer, capsys):
     # make viewer and add an image layer using our fixture
@@ -19,18 +43,3 @@ def test_example_q_widget(make_napari_viewer, capsys):
     # read captured output and check that it's as we expected
     captured = capsys.readouterr()
     assert captured.out == "napari has 1 layers\n"
-
-
-def test_example_magic_widget(make_napari_viewer, capsys):
-    viewer = make_napari_viewer()
-    layer = viewer.add_image(np.random.random((100, 100)))
-
-    # this time, our widget will be a MagicFactory or FunctionGui instance
-    my_widget = example_magic_widget()
-
-    # if we "call" this object, it'll execute our function
-    my_widget(viewer.layers[0])
-
-    # read captured output and check that it's as we expected
-    captured = capsys.readouterr()
-    assert captured.out == f"you have selected {layer}\n"

{{cookiecutter.plugin_name}}/src/{{cookiecutter.module_name}}/_widget.py

@@ -38,9 +38,9 @@
 # to indicate it should be wrapped as a magicgui to autogenerate
 # a widget.
 def example_function_widget(
-    img_layer: "napari.layers.Image",
+    img: "napari.types.ImageData",
 ) -> "napari.types.LabelsData":
-    return img_layer.data > 0.5
+    return img > 0.5
 
 
 # the magic_factory decorator lets us customize aspects of our widget
@@ -56,6 +56,8 @@ def example_magic_widget(
     return img_layer.data > threshold
 
 
+# if we want even more control over our widget, we can use
+# magicgui `Container`
 class ImageThreshold(Container):
     def __init__(self, viewer: "napari.viewer.Viewer"):
         super().__init__()