using pytest parametrize

Author: emmanuelle

contributing.md

@@ -158,6 +158,12 @@ pytest  packages/python/plotly/plotly/tests/test_core/
 pytest plotly/tests/test_plotly/test_plot.py
 ```
 
+or for a specfic test function
+
+```bash
+pytest plotly/tests/test_plotly/test_plot.py::test_function
+```
+
 ### Running tests with `tox`
 
 Running tests with tox is much more powerful, but requires a bit more setup.

packages/python/chart-studio/chart_studio/tests/test_plot_ly/test_image/test_image.py

@@ -5,77 +5,53 @@
 import os
 import itertools
 import warnings
-
+import pytest
 
 import _plotly_utils.exceptions
 from chart_studio.plotly import plotly as py
-from chart_studio.tests.utils import PlotlyTestCase
-
-
-class TestImage(PlotlyTestCase):
-    def setUp(self):
-        super(TestImage, self).setUp()
-        py.sign_in("PlotlyImageTest", "786r5mecv0")
-        self.data = [{"x": [1, 2, 3], "y": [3, 1, 6]}]
-
-
-def _generate_image_get_returns_valid_image_test(image_format, width, height, scale):
-    def test(self):
-        # TODO: better understand why this intermittently fails. See #649
-        num_attempts = 5
-        for i in range(num_attempts):
-            if i > 0:
-                warnings.warn("image test intermittently failed, retrying...")
-            try:
-                image = py.image.get(self.data, image_format, width, height, scale)
-                if image_format in ["png", "jpeg"]:
-                    assert imghdr.what("", image) == image_format
-                return
-            except (KeyError, _plotly_utils.exceptions.PlotlyError):
-                if i == num_attempts - 1:
-                    raise
-
-    return test
-
-
-def _generate_image_save_as_saves_valid_image(image_format, width, height, scale):
-    def _test(self):
-        f, filename = tempfile.mkstemp(".{}".format(image_format))
-        py.image.save_as(
-            self.data,
-            filename,
-            format=image_format,
-            width=width,
-            height=height,
-            scale=scale,
-        )
-        if image_format in ["png", "jpeg"]:
-            assert imghdr.what(filename) == image_format
-        else:
-            assert os.path.getsize(filename) > 0
-
-        os.remove(filename)
-
-    return _test
-
-
-kwargs = {
-    "format": ["png", "jpeg", "pdf", "svg", "emf"],
-    "width": [None, 300],
-    "height": [None, 300],
-    "scale": [None, 5],
-}
 
-for args in itertools.product(
-    kwargs["format"], kwargs["width"], kwargs["height"], kwargs["scale"]
-):
-    for test_generator in [
-        _generate_image_get_returns_valid_image_test,
-        _generate_image_save_as_saves_valid_image,
-    ]:
+py.sign_in("PlotlyImageTest", "786r5mecv0")
+data = [{"x": [1, 2, 3], "y": [3, 1, 6]}]
+
+
+@pytest.mark.parametrize('image_format', ("png", "jpeg", "pdf", "svg", "emf"))
+@pytest.mark.parametrize('width', (None, 300))
+@pytest.mark.parametrize('height', (None, 300))
+@pytest.mark.parametrize('scale', (None, 5))
+def test_image_get_returns_valid_image_test(image_format, width, height, scale):
+    # TODO: better understand why this intermittently fails. See #649
+    num_attempts = 5
+    for i in range(num_attempts):
+        if i > 0:
+            warnings.warn("image test intermittently failed, retrying...")
+        try:
+            image = py.image.get(data, image_format, width, height, scale)
+            if image_format in ["png", "jpeg"]:
+                assert imghdr.what("", image) == image_format
+            return
+        except (KeyError, _plotly_utils.exceptions.PlotlyError):
+            if i == num_attempts - 1:
+                raise
+
+
+@pytest.mark.parametrize('image_format', ("png", "jpeg", "pdf", "svg", "emf"))
+@pytest.mark.parametrize('width', (None, 300))
+@pytest.mark.parametrize('height', (None, 300))
+@pytest.mark.parametrize('scale', (None, 5))
+def test_image_save_as_saves_valid_image(image_format, width, height, scale):
+    f, filename = tempfile.mkstemp(".{}".format(image_format))
+    py.image.save_as(
+        data,
+        filename,
+        format=image_format,
+        width=width,
+        height=height,
+        scale=scale,
+    )
+    if image_format in ["png", "jpeg"]:
+        assert imghdr.what(filename) == image_format
+    else:
+        assert os.path.getsize(filename) > 0
+
+    os.remove(filename)
 
-        _test = test_generator(*args)
-        arg_string = ", ".join([str(a) for a in args])
-        test_name = test_generator.__name__.replace("_generate", "test")
-        test_name += "({})".format(arg_string)
-        setattr(TestImage, test_name, _test)