Check (& test) for None input(s)

stimuli/utils/resolution.py

@@ -132,7 +132,9 @@ def validate_shape(shape):
 
     # Check if sequence
     try:
-        len(shape)
+        if len(shape) < 1:
+            # Empty sequence
+            raise ValueError(f"shape must be of at least length 1: {shape}")
     except TypeError:  # not a sequence; make it one
         shape = (shape, shape)
 
@@ -171,7 +173,9 @@ def validate_ppd(ppd):
 
     # Check if sequence
     try:
-        len(ppd)
+        if len(ppd) < 1:
+            # Empty sequence
+            raise ValueError(f"ppd must be of at least length 1: {ppd}")
     except TypeError:  # not a sequence; make it one
         ppd = (ppd, ppd)
 
@@ -212,7 +216,9 @@ def validate_visual_size(visual_size):
 
     # Check if sequence
     try:
-        len(visual_size)
+        if len(visual_size) < 1:
+            # Empty sequence
+            raise ValueError(f"visual_size must be of at least length 1: {visual_size}")
     except TypeError:  # not a sequence; make it one
         visual_size = (visual_size, visual_size)
 

tests/test_validate_resolutions.py → tests/test_validate_resolution_components.py

@@ -1,4 +1,27 @@
-import numpy as np
+"""Tests whether validation of resolution components works as expected
+
+Seperately tests each of three components: visual size, shape, ppd.
+For each component, the validation routine has two expected major behaviors:
+- if input is valid, return canonical format (2-(named)tuple)
+  - casts values to correct type (float or int)
+  - expands 1D to 2D, i.e., if 1 value is provided, uses it for both dimensions
+- if input is not valid, raise specific exceptions:
+  - ValueError if input cannot be cast
+  - ValueError if values are not in accepted ranges, i.e., not positive
+  - TypeError if input is not a 1-Sequence or 2-Sequence
+
+The tests do this through parameterization:
+pytest runs each test for each of the specified parameter sets.
+
+For the valid-input tests, each parameter set specifies the (valid) input,
+and value (in canonical form) that should be returned.
+If the actual returned value matches this expected return value, the test passes.
+
+For the invalid-input tests, each parameter set specifies the (invalid) input,
+and the Exception that should be raised.
+If the function under testing raises this specified exception, the test passes.
+"""
+
 import pytest
 from stimuli.utils import resolution
 
@@ -21,23 +44,24 @@
         ((None, None), (None, None)),
     ],
 )
-def test_validate_visual_size(visual_size, expected):
+def test_valid_visual_size(visual_size, expected):
     out = resolution.validate_visual_size(visual_size)
     assert out.width == expected[1] and out.height == expected[0]
 
 
 @pytest.mark.parametrize(
     "visual_size, exception",
     [
+        ((), ValueError),
         ("bla", ValueError),
         ((32, 32, 32), TypeError),
         ({32, 32}, TypeError),
         ((-32, 16), ValueError),
         ((16, 0), ValueError),
     ],
 )
-def test_raises_visual_size(visual_size, exception):
-    with pytest.raises(exception) as e_info:
+def test_invalid_visual_size(visual_size, exception):
+    with pytest.raises(exception):
         resolution.validate_visual_size(visual_size)
 
 
@@ -54,26 +78,29 @@ def test_raises_visual_size(visual_size, exception):
         ("32", (32, 32)),
         ((16, "32"), (16, 32)),
         (("16", "32"), (16, 32)),
-        # Add None cases
+        ((16.1, None), (16, None)),
+        ((None, "32"), (None, 32)),
+        ((None, None), (None, None)),
     ],
 )
-def test_validate_shape(shape, expected):
+def test_valid_shape(shape, expected):
     out = resolution.validate_shape(shape)
     assert out.width == expected[1] and out.height == expected[0]
 
 
 @pytest.mark.parametrize(
     "shape, exception",
     [
+        ((), ValueError),
         ("bla", ValueError),
         ((32, 32, 32), TypeError),
         ({32, 32}, TypeError),
         ((-32, 16), ValueError),
         ((16, 0), ValueError),
     ],
 )
-def test_raises_shape(shape, exception):
-    with pytest.raises(exception) as e_info:
+def test_invalid_shape(shape, exception):
+    with pytest.raises(exception):
         resolution.validate_shape(shape)
 
 
@@ -85,29 +112,32 @@ def test_raises_shape(shape, exception):
     [
         ((32, 32), (32, 32)),
         ((16, 32), (16, 32)),
-        ((22.5, 48.1), (22, 48)),
+        ((22.5, 48.1), (22.5, 48.1)),
         ((16), (16, 16)),
         ("32", (32, 32)),
         ((16, "32"), (16, 32)),
         (("16", "32"), (16, 32)),
-        # Add None cases
+        ((16.1, None), (16.1, None)),
+        ((None, "32"), (None, 32)),
+        ((None, None), (None, None)),
     ],
 )
-def test_validate_ppd(ppd, expected):
+def test_valid_ppd(ppd, expected):
     out = resolution.validate_ppd(ppd)
     assert out.horizontal == expected[1] and out.vertical == expected[0]
 
 
 @pytest.mark.parametrize(
     "ppd, exception",
     [
+        ((), ValueError),
         ("bla", ValueError),
         ((32, 32, 32), TypeError),
         ({32, 32}, TypeError),
         ((-32, 16), ValueError),
         ((16, 0), ValueError),
     ],
 )
-def test_raises_ppd(ppd, exception):
-    with pytest.raises(exception) as e_info:
+def test_invalid_ppd(ppd, exception):
+    with pytest.raises(exception):
         resolution.validate_ppd(ppd)