Automating tests for eigen libary.

pydensecrf/test_eigen.py

 import numpy as np
 import eigen as e
 
-V = np.random.randn(3).astype(np.float32)
-M = np.random.randn(3,3).astype(np.float32)
+import pytest
 
-foo = e.vectorXf(V)
-assert np.all(np.array(foo) == V)
 
-foo = e.matrixXf(M)
-assert np.all(np.array(foo) == M)
+def test_vector_conversion():
+    np_vector = np.random.randn(3).astype(np.float32)
+    c_vector = e.vectorXf(np_vector)
+    assert np.all(np.array(c_vector) == np_vector)
+
+
+def test_matrix_conversion():
+    np_matrix = np.random.randn(3, 3).astype(np.float32)
+    assert(np_matrix.ndim == 2)
+    c_matrix = e.matrixXf(np_matrix)
+    assert np.all(np.array(c_matrix) == np_matrix)
+
+
+def test_wrong_dims():
+    np_matrix = np.random.randn(3, 3, 3).astype(np.float32)
+    assert(np_matrix.ndim == 3)
+    # c_matrix only supports ndim == 2
+    with pytest.raises(ValueError):
+        # Check whether a Value Error is raised
+        e.matrixXf(np_matrix)
+
+
+def test_wrong_type():
+    np_matrix = np.random.randn(3, 3, 3).astype(np.float64)
+    # c_matrix requies type np.float32
+    with pytest.raises(ValueError):
+        # Check whether a Value Error is raised
+        e.matrixXf(np_matrix)
+
+
+def test_none_type():
+    np_matrix = None
+    with pytest.raises(TypeError):
+        # Check whether a Value Error is raised
+        e.matrixXf(np_matrix)