log the missing handlers

ansibleplaybookgrapher/graph_model.py

@@ -580,25 +580,30 @@ def handlers(self) -> list["HandlerNode"]:
         """
         return self.get_nodes("handlers")
 
-    def get_handlers(self, notify: list[str]) -> list["HandlerNode"]:
+    def get_notified_handlers(
+        self, notify: list[str]
+    ) -> tuple[list["HandlerNode"], list[str]]:
         """Return the handlers notified by the given names if they exist
 
         You must calculate the indices before calling this method.
 
-        :param notify: The name of the handler to get.
-        :return:
+        :param notify: The names of the handler to get from the play.
+        :return: A tuple of the notified handlers and the names of the handlers that were not found.
         """
-        # TODO: add a warning when a notified handler is not found
-        result = []
+        notified_handlers: list[HandlerNode] = []
+        found: set[str] = set()
+
         for h in reversed(self.handlers):
-            if h in result:
+            if h in notified_handlers:
                 continue
 
             for n in notify:
                 if h.matches_handler(n):
-                    result.append(h)
+                    notified_handlers.append(h)
+                    found.add(n)
 
-        return sorted(result, key=lambda x: x.index)
+        not_found = set(notify) - found
+        return sorted(notified_handlers, key=lambda x: x.index), list(not_found)
 
     def to_dict(
         self,

ansibleplaybookgrapher/renderer/__init__.py

@@ -319,3 +319,19 @@ def get_node_url(self, node: Node) -> str | None:
             return url
 
         return None
+
+
+def log_handlers_not_found(
+    play_node: PlayNode, task_node: TaskNode, handlers_not_found: list[str]
+) -> None:
+    """Log the handlers that have not been found.
+
+    :param play_node: The play node
+    :param task_node: The task node
+    :param handlers_not_found: The handlers that have not been found.
+    :return:
+    """
+    for handler in handlers_not_found:
+        display.warning(
+            f"The handler '{handler}' notified by the task '{task_node.display_name()}' has not been found in the play '{play_node.display_name()}'."
+        )

ansibleplaybookgrapher/renderer/graphviz/__init__.py

@@ -25,7 +25,11 @@
     RoleNode,
     TaskNode,
 )
-from ansibleplaybookgrapher.renderer import PlaybookBuilder, Renderer
+from ansibleplaybookgrapher.renderer import (
+    PlaybookBuilder,
+    Renderer,
+    log_handlers_not_found,
+)
 from ansibleplaybookgrapher.renderer.graphviz.postprocessor import GraphvizPostProcessor
 
 display = Display()
@@ -206,7 +210,10 @@ def build_task(
 
         # Build the edge from the task to the handlers it notifies
         if self.show_handlers:
-            notified_handlers = play_node.get_handlers(task_node.notify)
+            notified_handlers, not_found = play_node.get_notified_handlers(
+                task_node.notify
+            )
+            log_handlers_not_found(play_node, task_node, not_found)
 
             for counter, handler in enumerate(notified_handlers, 1):
                 digraph.edge(

ansibleplaybookgrapher/renderer/mermaid.py

@@ -29,7 +29,11 @@
     RoleNode,
     TaskNode,
 )
-from ansibleplaybookgrapher.renderer import PlaybookBuilder, Renderer
+from ansibleplaybookgrapher.renderer import (
+    PlaybookBuilder,
+    Renderer,
+    log_handlers_not_found,
+)
 
 display = Display()
 
@@ -288,7 +292,10 @@ def build_task(
         )
 
         if self.show_handlers:
-            notified_handlers = play_node.get_handlers(task_node.notify)
+            notified_handlers, not_found = play_node.get_notified_handlers(
+                task_node.notify
+            )
+            log_handlers_not_found(play_node, task_node, not_found)
 
             for counter, handler in enumerate(notified_handlers, 1):
                 self.add_link(

tests/test_graph_model.py

@@ -308,13 +308,16 @@ def test_get_handlers_from_play():
 
     play.calculate_indices()
 
-    assert play.get_handlers(["fake handler"]) == []
-    assert play.get_handlers(["restart nginx"]) == [restart_nginx]
-    assert play.get_handlers(["restart postgres"]) == [restart_postgres]
+    assert play.get_notified_handlers(["fake handler"]) == ([], ["fake handler"])
+    assert play.get_notified_handlers(["restart nginx"]) == ([restart_nginx], [])
+    assert play.get_notified_handlers(["restart postgres"]) == ([restart_postgres], [])
 
-    mysql_handlers = play.get_handlers(["restart mysql"])
+    mysql_handlers, _ = play.get_notified_handlers(["restart mysql"])
     assert len(mysql_handlers) == 1
     assert mysql_handlers[0].id == restart_mysql_2.id
 
     # When multiple handlers have the same listen, we return them in the order they are defined
-    assert play.get_handlers(["restart dbs"]) == [restart_postgres, restart_mysql_2]
+    assert play.get_notified_handlers(["restart dbs"]) == (
+        [restart_postgres, restart_mysql_2],
+        [],
+    )