Add a unit test that breaks when concatenating kernels with ParcelsRandom functions in scipy

Error is `Error: name 'ParcelsRandom' is not defined`

Author: erikvansebille

tests/test_kernel_language.py

@@ -294,6 +294,25 @@ class TestParticle(ptype[mode]):
     assert np.allclose(pset.p, series, atol=1e-9)
 
 
+@pytest.mark.parametrize('mode', ['scipy', 'jit'])
+@pytest.mark.parametrize('concat', [False, True])
+def test_random_kernel_concat(fieldset, mode, concat):
+    class TestParticle(ptype[mode]):
+        p = Variable('p', dtype=np.float32)
+
+    pset = ParticleSet(fieldset, pclass=TestParticle, lon=0, lat=0)
+
+    def RandomKernel(particle, fieldset, time):
+        particle.p += ParcelsRandom.uniform(0, 1)
+
+    def AddOne(particle, fieldset, time):
+        particle.p += 1.
+
+    kernels = pset.Kernel(RandomKernel)+pset.Kernel(AddOne) if concat else RandomKernel
+    pset.execute(kernels, dt=0)
+    assert pset.p > 1 if concat else pset.p < 1
+
+
 @pytest.mark.parametrize('mode', ['scipy', 'jit'])
 @pytest.mark.parametrize('c_inc', ['str', 'file'])
 def test_c_kernel(fieldset, mode, c_inc):