ENH: Make aliases filters, factors, and classifiers to give them their methods

tests/pipeline/test_alias.py

@@ -0,0 +1,54 @@
+import numpy as np
+
+from zipline.testing.predicates import assert_equal
+from zipline.pipeline import Classifier, Factor, Filter
+from zipline.utils.numpy_utils import float64_dtype, int64_dtype
+
+from .base import BasePipelineTestCase
+
+
+class WithAlias(object):
+
+    def test_alias(self):
+        f = self.Term()
+        alias = f.alias('ayy lmao')
+
+        f_values = np.random.RandomState(5).randn(5, 5)
+
+        self.check_terms(
+            terms={
+                'f_alias': alias,
+            },
+            expected={
+                'f_alias': f_values,
+            },
+            initial_workspace={f: f_values},
+            mask=self.build_mask(np.ones((5, 5))),
+        )
+
+    def test_repr(self):
+        assert_equal(
+            repr(self.Term().alias('ayy lmao')),
+            "Aliased%s(..., name='ayy lmao')" % self.Term.__base__.__name__,
+        )
+
+
+class TestFactorAlias(WithAlias, BasePipelineTestCase):
+    class Term(Factor):
+        dtype = float64_dtype
+        inputs = ()
+        window_length = 0
+
+
+class TestFilterAlias(WithAlias, BasePipelineTestCase):
+    class Term(Filter):
+        inputs = ()
+        window_length = 0
+
+
+class TestClassifierAlias(WithAlias, BasePipelineTestCase):
+    class Term(Classifier):
+        dtype = int64_dtype
+        inputs = ()
+        window_length = 0
+        missing_value = -1