[tests] add pytest for algorithm

see #642

pytests/util/test_algorithm.py

@@ -0,0 +1,50 @@
+import pytest
+
+from util.algorithm import *
+
+@pytest.fixture
+def someData():
+    return {"a": 100, "b": 200, "c": [1, 2, 3]}
+
+@pytest.fixture
+def differentData():
+    return {"x": 20, "y": "bla", "z": ["a", "b"]}
+
+@pytest.fixture
+def moreData():
+    return {"n": 100}
+
+@pytest.fixture
+def overlapData():
+    return {"a": 200, "c": [1, 2, 4]}
+
+def test_merge_with_empty(someData):
+    assert merge(someData, {}) == someData
+    assert merge(someData, None) == None
+
+    def test_merge_no_overwrite(someData, differentData):
+        result = merge(someData, differentData)
+        for k in someData:
+            assert someData[k] == result[k]
+        for k in self.differentData:
+            assert differentData[k] == result[k]
+
+    def test_merge_multiple(someData, differentData, moreData):
+        result = merge(someData, differentData, moreData)
+        for k in someData:
+            assert someData[k] == result[k]
+        for k in differentData:
+            assert differentData[k] == result[k]
+        for k in moreData:
+            assert moreData[k] == result[k]
+
+    def merge_overlap(someData, overlapData):
+        result = merge(someData, overlapData)
+        for k in someData:
+            if not k in self.overlapData:
+                assert someData[k] == result[k]
+        for k in self.overlapData:
+            assert overlapData[k] == result[k]
+
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4