clanker: veet-hard-problems (run)

problems/hard/task-scheduler/tests.py

@@ -0,0 +1,79 @@
+"""Tests for task-scheduler."""
+import pytest
+from solution import schedule_tasks
+
+
+class TestBasicCases:
+    """Test basic functionality with typical inputs."""
+
+    def test_example_one(self):
+        """Test first example from problem description."""
+        tasks = [("compile", 3, []), ("test", 5, ["compile"]), ("lint", 2, []), ("deploy", 1, ["test", "lint"])]
+        assert schedule_tasks(tasks) == (9, ["compile", "test", "deploy"])
+
+    def test_example_two_cycle(self):
+        """Test second example with circular dependency."""
+        tasks = [("A", 2, ["B"]), ("B", 3, ["A"])]
+        assert schedule_tasks(tasks) == (-1, [])
+
+    def test_example_three_parallel(self):
+        """Test parallel tasks with shared dependency."""
+        tasks = [("X", 4, []), ("Y", 4, []), ("Z", 1, ["X", "Y"])]
+        cost, path = schedule_tasks(tasks)
+        assert cost == 5
+        assert path[0] in ("X", "Y") and path[-1] == "Z"
+
+    def test_linear_chain(self):
+        """Test simple linear dependency chain."""
+        tasks = [("A", 2, []), ("B", 3, ["A"]), ("C", 4, ["B"])]
+        assert schedule_tasks(tasks) == (9, ["A", "B", "C"])
+
+
+class TestEdgeCases:
+    """Test edge cases and boundary conditions."""
+
+    def test_single_task(self):
+        """Test with a single task and no dependencies."""
+        tasks = [("solo", 5, [])]
+        assert schedule_tasks(tasks) == (5, ["solo"])
+
+    def test_all_independent(self):
+        """Test all tasks run in parallel with no dependencies."""
+        tasks = [("A", 3, []), ("B", 7, []), ("C", 5, [])]
+        cost, path = schedule_tasks(tasks)
+        assert cost == 7
+        assert path == ["B"]
+
+    def test_diamond_dependency(self):
+        """Test diamond-shaped dependency graph."""
+        tasks = [("A", 1, []), ("B", 5, ["A"]), ("C", 2, ["A"]), ("D", 1, ["B", "C"])]
+        assert schedule_tasks(tasks) == (7, ["A", "B", "D"])
+
+    def test_three_node_cycle(self):
+        """Test cycle involving three nodes."""
+        tasks = [("A", 1, ["C"]), ("B", 1, ["A"]), ("C", 1, ["B"])]
+        assert schedule_tasks(tasks) == (-1, [])
+
+    def test_wide_fan_in(self):
+        """Test many tasks feeding into one final task."""
+        tasks = [("A", 1, []), ("B", 2, []), ("C", 3, []), ("D", 4, []), ("final", 1, ["A", "B", "C", "D"])]
+        assert schedule_tasks(tasks) == (5, ["D", "final"])
+
+    def test_deep_chain_with_parallel_branch(self):
+        """Test long chain alongside a shorter parallel branch."""
+        tasks = [
+            ("A", 1, []), ("B", 1, ["A"]), ("C", 1, ["B"]), ("D", 1, ["C"]),
+            ("shortcut", 2, []),
+            ("end", 1, ["D", "shortcut"]),
+        ]
+        assert schedule_tasks(tasks) == (5, ["A", "B", "C", "D", "end"])
+
+    def test_partial_cycle_with_valid_tasks(self):
+        """Test graph where some tasks form a cycle but others don't."""
+        tasks = [("A", 1, []), ("B", 2, ["C"]), ("C", 3, ["B"])]
+        assert schedule_tasks(tasks) == (-1, [])
+
+    def test_large_durations(self):
+        """Test with large task durations."""
+        tasks = [("A", 1000000, []), ("B", 1000000, ["A"])]
+        assert schedule_tasks(tasks) == (2000000, ["A", "B"])