Add simple tests for DependencySolver

tracetools_analysis/test/tracetools_analysis/test_dependency_solver.py

@@ -0,0 +1,107 @@
+# Copyright 2019 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+
+from tracetools_analysis.processor import Dependant
+from tracetools_analysis.processor import DependencySolver
+
+
+class DepEmtpy(Dependant):
+    pass
+
+
+class DepOne(Dependant):
+
+    @staticmethod
+    def dependencies():
+        return [DepEmtpy]
+
+
+class DepOne2(Dependant):
+
+    @staticmethod
+    def dependencies():
+        return [DepEmtpy]
+
+class DepTwo(Dependant):
+
+    @staticmethod
+    def dependencies():
+        return [DepOne, DepOne2]
+
+
+class TestDependencySolver(unittest.TestCase):
+
+    def __init__(self, *args) -> None:
+        super().__init__(
+            *args,
+        )
+
+    def test_single_dep(self) -> None:
+        depone_instance = DepOne()
+
+        # DepEmtpy should be added before
+        solution = DependencySolver([depone_instance]).solve()
+        self.assertEqual(len(solution), 2, 'solution length invalid')
+        self.assertIsInstance(solution[0], DepEmtpy)
+        self.assertIs(solution[1], depone_instance)
+    
+    def test_single_dep_existing(self) -> None:
+        depempty_instance = DepEmtpy()
+        depone_instance = DepOne()
+
+        # Already in order
+        solution = DependencySolver([depempty_instance, depone_instance]).solve()
+        self.assertEqual(len(solution), 2, 'solution length invalid')
+        self.assertIs(solution[0], depempty_instance, 'wrong solution order')
+        self.assertIs(solution[1], depone_instance, 'wrong solution order')
+
+        # Out of order
+        solution = DependencySolver([depone_instance, depempty_instance]).solve()
+        self.assertEqual(len(solution), 2, 'solution length invalid')
+        self.assertIs(solution[0], depempty_instance, 'solution does not use existing instance')
+        self.assertIs(solution[1], depone_instance, 'solution does not use existing instance')
+
+    def test_duplicate_dependency(self) -> None:
+        deptwo_instance = DepTwo()
+
+        # DepOne and DepOne2 both depend on DepEmpty
+        solution = DependencySolver([deptwo_instance]).solve()
+        self.assertEqual(len(solution), 4, 'solution length invalid')
+        self.assertIsInstance(solution[0], DepEmtpy)
+        self.assertIsInstance(solution[1], DepOne)
+        self.assertIsInstance(solution[2], DepOne2)
+        self.assertIs(solution[3], deptwo_instance)
+
+        # Existing instance of DepEmpty, in order
+        depempty_instance = DepEmtpy()
+        solution = DependencySolver([depempty_instance, deptwo_instance]).solve()
+        self.assertEqual(len(solution), 4, 'solution length invalid')
+        self.assertIsInstance(solution[0], DepEmtpy)
+        self.assertIsInstance(solution[1], DepOne)
+        self.assertIsInstance(solution[2], DepOne2)
+        self.assertIs(solution[3], deptwo_instance)
+
+        # Existing instance of DepEmpty, not in order
+        solution = DependencySolver([deptwo_instance, depempty_instance]).solve()
+        self.assertEqual(len(solution), 4, 'solution length invalid')
+        self.assertIsInstance(solution[0], DepEmtpy)
+        self.assertIsInstance(solution[1], DepOne)
+        self.assertIsInstance(solution[2], DepOne2)
+        self.assertIs(solution[3], deptwo_instance)
+
+
+if __name__ == '__main__':
+    unittest.main()