add workflow test

Author: josephmje

dmriprep/workflows/dwi/util.py

@@ -31,7 +31,7 @@ def init_dwi_reference_wf(omp_nthreads, dwi_file=None,
     intensity values, and calculates a median image.
 
     Then, the reference b0 and its skull-stripped version are generated using
-    a custom methodology taken from *niworkflows*.
+    a custom methodology adapted from *niworkflows*.
 
     .. workflow::
         :graph2use: orig

dmriprep/workflows/tests/__init__.py

@@ -0,0 +1,44 @@
+"""Test util workflows."""
+import pytest
+
+from niworkflows.engine.workflows import LiterateWorkflow as Workflow
+from nipype.pipeline import engine as pe
+
+from dmriprep.workflows.dwi.util import init_dwi_reference_wf
+from dmriprep.interfaces.vectors import CheckGradientTable
+
+
+@pytest.mark.parametrize('dataset', [
+    'THP002'
+])
+def test_util(bids_layouts, tmpdir, output_path, dataset, workdir):
+    """Test creation of the workflow."""
+    tmpdir.chdir()
+
+    data = bids_layouts[dataset]
+    wf = Workflow(name='util_%s' % dataset)
+    util_wf = init_dwi_reference_wf(omp_nthreads=1)
+
+    dwi_file = data.get(
+        datatype='dwi',
+        return_type='file',
+        extension=['.nii', '.nii.gz'])
+
+    bvec_file = data.get_bvec(dwi_file)
+    bval_file = data.get_bval(dwi_file)
+
+    gradient_table = pe.Node(CheckGradientTable(
+        dwi_file=dwi_file,
+        in_bvec=bvec_file,
+        in_bval=bval_file), name='gradient_table')
+
+    util_wf.inputs.inputnode.dwi_file = dwi_file
+
+    wf.connect([
+        gradient_table, util_wf, [('b0_ixs', 'b0_ixs')],
+    ])
+
+    if workdir:
+        wf.base_dir = str(workdir)
+
+    wf.run()