TST: Test dimension, size, and fnum constraints

Squeeze array to simplify dimension test

Author: effigies

nibabel/freesurfer/io.py

@@ -184,22 +184,22 @@ def write_morph_data(file_like, values, fnum=0):
     """
     magic_bytes = np.array([255, 255, 255], dtype=np.uint8)
 
+    array = np.asarray(values).astype('>f4').squeeze()
+    if len(array.shape) > 1:
+        raise ValueError("Multi-dimensional values not supported")
+
     i4info = np.iinfo('i4')
-    if len(values) > i4info.max:
+    if len(array) > i4info.max:
         raise ValueError("Too many values for morphometry file")
     if not i4info.min <= fnum <= i4info.max:
         raise ValueError("Argument fnum must be between {0} and {1}".format(
                          i4info.min, i4info.max))
 
-    array = np.asarray(values).astype('>f4')
-    if len(array.shape) > 1:
-        raise ValueError("Multi-dimensional values not supported")
-
     with Opener(file_like, 'wb') as fobj:
         fobj.write(magic_bytes)
 
         # vertex count, face count (unused), vals per vertex (only 1 supported)
-        fobj.write(np.array([len(values), fnum, 1], dtype='>i4'))
+        fobj.write(np.array([len(array), fnum, 1], dtype='>i4'))
 
         fobj.write(array)
 

nibabel/freesurfer/tests/test_io.py

@@ -10,12 +10,13 @@
 
 from nose.tools import assert_true
 import numpy as np
-from numpy.testing import assert_equal, dec
+from numpy.testing import assert_equal, assert_raises, dec
 
 from .. import (read_geometry, read_morph_data, read_annot, read_label,
                 write_geometry, write_morph_data, write_annot)
 
 from ...tests.nibabel_data import get_nibabel_data
+from ...fileslice import strided_scalar
 
 
 DATA_SDIR = 'fsaverage'
@@ -99,6 +100,25 @@ def test_morph_data():
         assert_equal(curv2, curv)
 
 
+def test_write_morph_data():
+    """Test write_morph_data edge cases"""
+    values = np.arange(20, dtype='>f4')
+    okay_shapes = [(20,), (20, 1), (20, 1, 1), (1, 20)]
+    bad_shape = (10, 2)
+    big_num = np.iinfo('i4').max + 1
+    with InTemporaryDirectory():
+        for shape in okay_shapes:
+            write_morph_data('test.curv', values.reshape(shape))
+            # Check ordering is preserved, regardless of shape
+            assert_equal(values, read_morph_data('test.curv'))
+        assert_raises(ValueError, write_morph_data, 'test.curv',
+                      np.zeros(shape), big_num)
+        assert_raises(ValueError, write_morph_data, 'test.curv',
+                      values.reshape(bad_shape))
+        assert_raises(ValueError, write_morph_data, 'test.curv',
+                      strided_scalar((big_num,)))
+
+
 @freesurfer_test
 def test_annot():
     """Test IO of .annot"""