TEST: Add nested iterables test

Author: effigies

nipype/pipeline/engine/tests/test_join.py

@@ -627,3 +627,35 @@ def sq(x):
                               joinfield=['in1'])
     wf.connect(square, 'out', square_join, "in1")
     wf.run()
+
+
+def test_join_nestediters(tmpdir):
+    tmpdir.chdir()
+
+    def exponent(x, p):
+        return x ** p
+
+    wf = pe.Workflow('wf', base_dir=tmpdir.strpath)
+
+    xs = pe.Node(IdentityInterface(['x']),
+                 iterables=[('x', [1, 2])],
+                 name='xs')
+    ps = pe.Node(IdentityInterface(['p']),
+                 iterables=[('p', [3, 4])],
+                 name='ps')
+    exp = pe.Node(Function(function=exponent), name='exp')
+    exp_joinx = pe.JoinNode(Merge(1, ravel_inputs=True),
+                            name='exp_joinx',
+                            joinsource='xs',
+                            joinfield=['in1'])
+    exp_joinp = pe.JoinNode(Merge(1, ravel_inputs=True),
+                            name='exp_joinp',
+                            joinsource='ps',
+                            joinfield=['in1'])
+    wf.connect([
+        (xs, exp, [('x', 'x')]),
+        (ps, exp, [('p', 'p')]),
+        (exp, exp_joinx, [('out', 'in1')]),
+        (exp_joinx, exp_joinp, [('out', 'in1')])])
+
+    wf.run()