diff --git a/addons/queue_job/tests/test_delayable.py b/addons/queue_job/tests/test_delayable.py
new file mode 100644
index 0000000..df4c3cf
--- /dev/null
+++ b/addons/queue_job/tests/test_delayable.py
@@ -0,0 +1,287 @@
+# copyright 2019 Camptocamp
+# license agpl-3.0 or later (http://www.gnu.org/licenses/agpl.html)
+
+import gc
+import logging
+from unittest import mock
+
+from odoo.tests import common
+
+from odoo.addons.queue_job.delay import Delayable, DelayableGraph
+
+
+class TestDelayable(common.BaseCase):
+    def setUp(self):
+        super().setUp()
+        self.recordset = mock.MagicMock(name="recordset")
+
+    def test_delayable_set(self):
+        # Use gc for garbage collection and use assertLogs to suppress WARNING
+        with self.assertLogs("odoo.addons.queue_job.delay", level=logging.WARNING):
+            dl = Delayable(self.recordset)
+            dl.set(priority=15)
+            self.assertEqual(dl.priority, 15)
+            dl.set({"priority": 20, "description": "test"})
+            self.assertEqual(dl.priority, 20)
+            self.assertEqual(dl.description, "test")
+            del dl
+            gc.collect()
+
+    def test_delayable_set_unknown(self):
+        # Use gc for garbage collection and use assertLogs to suppress WARNING
+        with self.assertLogs("odoo.addons.queue_job.delay", level=logging.WARNING):
+            dl = Delayable(self.recordset)
+            with self.assertRaises(ValueError):
+                dl.set(foo=15)
+            del dl
+            gc.collect()
+
+    def test_graph_add_vertex_edge(self):
+        graph = DelayableGraph()
+        graph.add_vertex("a")
+        self.assertEqual(graph._graph, {"a": set()})
+        graph.add_edge("a", "b")
+        self.assertEqual(graph._graph, {"a": {"b"}, "b": set()})
+        graph.add_edge("b", "c")
+        self.assertEqual(graph._graph, {"a": {"b"}, "b": {"c"}, "c": set()})
+
+    def test_graph_vertices(self):
+        graph = DelayableGraph({"a": {"b"}, "b": {"c"}, "c": set()})
+        self.assertEqual(graph.vertices(), {"a", "b", "c"})
+
+    def test_graph_edges(self):
+        graph = DelayableGraph(
+            {"a": {"b"}, "b": {"c", "d"}, "c": {"e"}, "d": set(), "e": set()}
+        )
+        self.assertEqual(
+            sorted(graph.edges()),
+            sorted(
+                [
+                    ("a", "b"),
+                    ("b", "c"),
+                    ("b", "d"),
+                    ("c", "e"),
+                ]
+            ),
+        )
+
+    def test_graph_connect(self):
+        # Use gc for garbage collection and use assertLogs to suppress WARNING
+        with self.assertLogs("odoo.addons.queue_job.delay", level=logging.WARNING):
+            node_tail = Delayable(self.recordset)
+            node_tail2 = Delayable(self.recordset)
+            node_middle = Delayable(self.recordset)
+            node_top = Delayable(self.recordset)
+            node_middle.on_done(node_tail)
+            node_middle.on_done(node_tail2)
+            node_top.on_done(node_middle)
+            collected = node_top._graph._connect_graphs()
+            self.assertEqual(
+                collected._graph,
+                {
+                    node_tail: set(),
+                    node_tail2: set(),
+                    node_middle: {node_tail, node_tail2},
+                    node_top: {node_middle},
+                },
+            )
+
+            del node_tail, node_tail2, node_middle, node_top, collected
+            gc.collect()
+
+    def test_graph_paths(self):
+        graph = DelayableGraph(
+            {"a": {"b"}, "b": {"c", "d"}, "c": {"e"}, "d": set(), "e": set()}
+        )
+        paths = list(graph.paths("a"))
+        self.assertEqual(sorted(paths), sorted([["a", "b", "d"], ["a", "b", "c", "e"]]))
+        paths = list(graph.paths("b"))
+        self.assertEqual(sorted(paths), sorted([["b", "d"], ["b", "c", "e"]]))
+        paths = list(graph.paths("c"))
+        self.assertEqual(paths, [["c", "e"]])
+        paths = list(graph.paths("d"))
+        self.assertEqual(paths, [["d"]])
+        paths = list(graph.paths("e"))
+        self.assertEqual(paths, [["e"]])
+
+    def test_graph_repr(self):
+        graph = DelayableGraph(
+            {"a": {"b"}, "b": {"c", "d"}, "c": {"e"}, "d": set(), "e": set()}
+        )
+        actual = repr(graph)
+        expected = ["'a' → 'b' → 'c' → 'e'", "'a' → 'b' → 'd'"]
+        self.assertEqual(sorted(actual.split("\n")), expected)
+
+    def test_graph_topological_sort(self):
+        # the graph is an example from
+        # https://en.wikipedia.org/wiki/Topological_sorting
+        # if you want a visual representation
+        graph = DelayableGraph(
+            {
+                5: {11},
+                7: {11, 8},
+                3: {8, 10},
+                11: {2, 9, 10},
+                2: set(),
+                8: {9},
+                9: set(),
+                10: set(),
+            }
+        )
+
+        # these are all the pre-computed combinations that
+        # respect the dependencies order
+        valid_solutions = [
+            [3, 5, 7, 8, 11, 2, 9, 10],
+            [3, 5, 7, 8, 11, 2, 10, 9],
+            [3, 5, 7, 8, 11, 9, 2, 10],
+            [3, 5, 7, 8, 11, 9, 10, 2],
+            [3, 5, 7, 8, 11, 10, 2, 9],
+            [3, 5, 7, 8, 11, 10, 9, 2],
+            [3, 5, 7, 11, 2, 8, 9, 10],
+            [3, 5, 7, 11, 2, 8, 10, 9],
+            [3, 5, 7, 11, 2, 10, 8, 9],
+            [3, 5, 7, 11, 8, 2, 9, 10],
+            [3, 5, 7, 11, 8, 2, 10, 9],
+            [3, 5, 7, 11, 8, 9, 2, 10],
+            [3, 5, 7, 11, 8, 9, 10, 2],
+            [3, 5, 7, 11, 8, 10, 2, 9],
+            [3, 5, 7, 11, 8, 10, 9, 2],
+            [3, 5, 7, 11, 10, 2, 8, 9],
+            [3, 5, 7, 11, 10, 8, 2, 9],
+            [3, 5, 7, 11, 10, 8, 9, 2],
+            [3, 7, 5, 8, 11, 2, 9, 10],
+            [3, 7, 5, 8, 11, 2, 10, 9],
+            [3, 7, 5, 8, 11, 9, 2, 10],
+            [3, 7, 5, 8, 11, 9, 10, 2],
+            [3, 7, 5, 8, 11, 10, 2, 9],
+            [3, 7, 5, 8, 11, 10, 9, 2],
+            [3, 7, 5, 11, 2, 8, 9, 10],
+            [3, 7, 5, 11, 2, 8, 10, 9],
+            [3, 7, 5, 11, 2, 10, 8, 9],
+            [3, 7, 5, 11, 8, 2, 9, 10],
+            [3, 7, 5, 11, 8, 2, 10, 9],
+            [3, 7, 5, 11, 8, 9, 2, 10],
+            [3, 7, 5, 11, 8, 9, 10, 2],
+            [3, 7, 5, 11, 8, 10, 2, 9],
+            [3, 7, 5, 11, 8, 10, 9, 2],
+            [3, 7, 5, 11, 10, 2, 8, 9],
+            [3, 7, 5, 11, 10, 8, 2, 9],
+            [3, 7, 5, 11, 10, 8, 9, 2],
+            [3, 7, 8, 5, 11, 2, 9, 10],
+            [3, 7, 8, 5, 11, 2, 10, 9],
+            [3, 7, 8, 5, 11, 9, 2, 10],
+            [3, 7, 8, 5, 11, 9, 10, 2],
+            [3, 7, 8, 5, 11, 10, 2, 9],
+            [3, 7, 8, 5, 11, 10, 9, 2],
+            [5, 3, 7, 8, 11, 2, 9, 10],
+            [5, 3, 7, 8, 11, 2, 10, 9],
+            [5, 3, 7, 8, 11, 9, 2, 10],
+            [5, 3, 7, 8, 11, 9, 10, 2],
+            [5, 3, 7, 8, 11, 10, 2, 9],
+            [5, 3, 7, 8, 11, 10, 9, 2],
+            [5, 3, 7, 11, 2, 8, 9, 10],
+            [5, 3, 7, 11, 2, 8, 10, 9],
+            [5, 3, 7, 11, 2, 10, 8, 9],
+            [5, 3, 7, 11, 8, 2, 9, 10],
+            [5, 3, 7, 11, 8, 2, 10, 9],
+            [5, 3, 7, 11, 8, 9, 2, 10],
+            [5, 3, 7, 11, 8, 9, 10, 2],
+            [5, 3, 7, 11, 8, 10, 2, 9],
+            [5, 3, 7, 11, 8, 10, 9, 2],
+            [5, 3, 7, 11, 10, 2, 8, 9],
+            [5, 3, 7, 11, 10, 8, 2, 9],
+            [5, 3, 7, 11, 10, 8, 9, 2],
+            [5, 7, 3, 8, 11, 2, 9, 10],
+            [5, 7, 3, 8, 11, 2, 10, 9],
+            [5, 7, 3, 8, 11, 9, 2, 10],
+            [5, 7, 3, 8, 11, 9, 10, 2],
+            [5, 7, 3, 8, 11, 10, 2, 9],
+            [5, 7, 3, 8, 11, 10, 9, 2],
+            [5, 7, 3, 11, 2, 8, 9, 10],
+            [5, 7, 3, 11, 2, 8, 10, 9],
+            [5, 7, 3, 11, 2, 10, 8, 9],
+            [5, 7, 3, 11, 8, 2, 9, 10],
+            [5, 7, 3, 11, 8, 2, 10, 9],
+            [5, 7, 3, 11, 8, 9, 2, 10],
+            [5, 7, 3, 11, 8, 9, 10, 2],
+            [5, 7, 3, 11, 8, 10, 2, 9],
+            [5, 7, 3, 11, 8, 10, 9, 2],
+            [5, 7, 3, 11, 10, 2, 8, 9],
+            [5, 7, 3, 11, 10, 8, 2, 9],
+            [5, 7, 3, 11, 10, 8, 9, 2],
+            [5, 7, 11, 2, 3, 8, 9, 10],
+            [5, 7, 11, 2, 3, 8, 10, 9],
+            [5, 7, 11, 2, 3, 10, 8, 9],
+            [5, 7, 11, 3, 2, 8, 9, 10],
+            [5, 7, 11, 3, 2, 8, 10, 9],
+            [5, 7, 11, 3, 2, 10, 8, 9],
+            [5, 7, 11, 3, 8, 2, 9, 10],
+            [5, 7, 11, 3, 8, 2, 10, 9],
+            [5, 7, 11, 3, 8, 9, 2, 10],
+            [5, 7, 11, 3, 8, 9, 10, 2],
+            [5, 7, 11, 3, 8, 10, 2, 9],
+            [5, 7, 11, 3, 8, 10, 9, 2],
+            [5, 7, 11, 3, 10, 2, 8, 9],
+            [5, 7, 11, 3, 10, 8, 2, 9],
+            [5, 7, 11, 3, 10, 8, 9, 2],
+            [7, 3, 5, 8, 11, 2, 9, 10],
+            [7, 3, 5, 8, 11, 2, 10, 9],
+            [7, 3, 5, 8, 11, 9, 2, 10],
+            [7, 3, 5, 8, 11, 9, 10, 2],
+            [7, 3, 5, 8, 11, 10, 2, 9],
+            [7, 3, 5, 8, 11, 10, 9, 2],
+            [7, 3, 5, 11, 2, 8, 9, 10],
+            [7, 3, 5, 11, 2, 8, 10, 9],
+            [7, 3, 5, 11, 2, 10, 8, 9],
+            [7, 3, 5, 11, 8, 2, 9, 10],
+            [7, 3, 5, 11, 8, 2, 10, 9],
+            [7, 3, 5, 11, 8, 9, 2, 10],
+            [7, 3, 5, 11, 8, 9, 10, 2],
+            [7, 3, 5, 11, 8, 10, 2, 9],
+            [7, 3, 5, 11, 8, 10, 9, 2],
+            [7, 3, 5, 11, 10, 2, 8, 9],
+            [7, 3, 5, 11, 10, 8, 2, 9],
+            [7, 3, 5, 11, 10, 8, 9, 2],
+            [7, 3, 8, 5, 11, 2, 9, 10],
+            [7, 3, 8, 5, 11, 2, 10, 9],
+            [7, 3, 8, 5, 11, 9, 2, 10],
+            [7, 3, 8, 5, 11, 9, 10, 2],
+            [7, 3, 8, 5, 11, 10, 2, 9],
+            [7, 3, 8, 5, 11, 10, 9, 2],
+            [7, 5, 3, 8, 11, 2, 9, 10],
+            [7, 5, 3, 8, 11, 2, 10, 9],
+            [7, 5, 3, 8, 11, 9, 2, 10],
+            [7, 5, 3, 8, 11, 9, 10, 2],
+            [7, 5, 3, 8, 11, 10, 2, 9],
+            [7, 5, 3, 8, 11, 10, 9, 2],
+            [7, 5, 3, 11, 2, 8, 9, 10],
+            [7, 5, 3, 11, 2, 8, 10, 9],
+            [7, 5, 3, 11, 2, 10, 8, 9],
+            [7, 5, 3, 11, 8, 2, 9, 10],
+            [7, 5, 3, 11, 8, 2, 10, 9],
+            [7, 5, 3, 11, 8, 9, 2, 10],
+            [7, 5, 3, 11, 8, 9, 10, 2],
+            [7, 5, 3, 11, 8, 10, 2, 9],
+            [7, 5, 3, 11, 8, 10, 9, 2],
+            [7, 5, 3, 11, 10, 2, 8, 9],
+            [7, 5, 3, 11, 10, 8, 2, 9],
+            [7, 5, 3, 11, 10, 8, 9, 2],
+            [7, 5, 11, 2, 3, 8, 9, 10],
+            [7, 5, 11, 2, 3, 8, 10, 9],
+            [7, 5, 11, 2, 3, 10, 8, 9],
+            [7, 5, 11, 3, 2, 8, 9, 10],
+            [7, 5, 11, 3, 2, 8, 10, 9],
+            [7, 5, 11, 3, 2, 10, 8, 9],
+            [7, 5, 11, 3, 8, 2, 9, 10],
+            [7, 5, 11, 3, 8, 2, 10, 9],
+            [7, 5, 11, 3, 8, 9, 2, 10],
+            [7, 5, 11, 3, 8, 9, 10, 2],
+            [7, 5, 11, 3, 8, 10, 2, 9],
+            [7, 5, 11, 3, 8, 10, 9, 2],
+            [7, 5, 11, 3, 10, 2, 8, 9],
+            [7, 5, 11, 3, 10, 8, 2, 9],
+            [7, 5, 11, 3, 10, 8, 9, 2],
+        ]
+
+        self.assertIn(list(graph.topological_sort()), valid_solutions)