tests: Add tests for generation of sorted dependency tree

tests/test_viewport.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from datetime import datetime
 from tests.base import IntegrationTest
 from time import sleep
 
@@ -156,3 +157,48 @@ class TestViewportsUnicodeTaskGeneration(IntegrationTest):
 
     def execute(self):
         self.command("w", regex="written$", lines=1)
+
+
+class TestViewportsTaskSortedGeneration(IntegrationTest):
+
+    viminput = """
+    === Work tasks | +work ===
+    """
+
+    vimoutput = """
+    === Work tasks | +work ===
+    * [ ] main task 1 (2015-08-07 00:00)  #{uuid}
+        * [ ] sub task 1a (2015-08-01 00:00)  #{uuid}
+            * [ ] sub task 1aa  #{uuid}
+        * [ ] sub task 1b  #{uuid}
+    * [ ] main task 2 (2015-08-08 00:00)  #{uuid}
+    * [ ] main task 3 (2015-08-09 00:00)  #{uuid}
+        * [ ] sub task 3a (2015-08-03 00:00)  #{uuid}
+        * [ ] sub task 3b  #{uuid}
+    * [ ] main task 4  #{uuid}
+    """
+
+    tasks = [
+        dict(description="main task 3", tags=['work'], due=datetime(2015,8,9)),
+        dict(description="main task 2", tags=['work'], due=datetime(2015,8,8)),
+        dict(description="main task 1", tags=['work'], due=datetime(2015,8,7)),
+        dict(description="main task 4", tags=['work']),
+        dict(description="sub task 1b", tags=['work']),
+        dict(description="sub task 1a", tags=['work'], due=datetime(2015,8,1)),
+        dict(description="sub task 1aa", tags=['work']),
+        dict(description="sub task 3b", tags=['work']),
+        dict(description="sub task 3a", tags=['work'], due=datetime(2015,8,3)),
+    ]
+
+    def execute(self):
+        # Mark the dependencies
+        self.tasks[2]['depends'].add(self.tasks[4])
+        self.tasks[2]['depends'].add(self.tasks[5])
+        self.tasks[0]['depends'].add(self.tasks[7])
+        self.tasks[0]['depends'].add(self.tasks[8])
+        self.tasks[5]['depends'].add(self.tasks[6])
+
+        for task in self.tasks:
+            task.save()
+
+        self.command("w", regex="written$", lines=1)