Ensure that xtrigger OR fails validation

changes.d/6772.fix.md

@@ -0,0 +1 @@
+Xtriggers with an OR operator (`|`) between them now correctly fails validation as Cylc does not support this.

cylc/flow/config.py

@@ -1841,6 +1841,7 @@ def generate_edges(self, lexpr, orig_lexpr, left_nodes, right, seq,
             # Right is a lone node.
             self.edges[seq].add((right, None, suicide, conditional))
 
+        conditional_xtriggers = []
         for left in left_nodes:
             # if left is None:
             #    continue
@@ -1856,7 +1857,16 @@ def generate_edges(self, lexpr, orig_lexpr, left_nodes, right, seq,
                     LOG.error(f"{orig_lexpr} => {right}")
                 raise WorkflowConfigError(
                     f"self-edge detected: {left} => {right}")
-            self.edges[seq].add((left, right, suicide, conditional))
+            if left.startswith('@') and conditional:
+                conditional_xtriggers.append(f'{lexpr} => {right}')
+            else:
+                self.edges[seq].add((left, right, suicide, conditional))
+        if conditional_xtriggers:
+            raise WorkflowConfigError(
+                'Xtriggers cannot be used in conditional graph'
+                ' expressions:\n' +
+                '\n * '.join(conditional_xtriggers)
+            )
 
     def generate_taskdef(self, orig_expr, node):
         """Generate task definition for node."""

tests/integration/test_config.py

@@ -34,6 +34,7 @@
 from cylc.flow.pathutil import get_workflow_run_pub_db_path
 
 Fixture = Any
+param = pytest.param
 
 
 @pytest.mark.parametrize(
@@ -488,6 +489,44 @@ def test_xtrig_signature_validation(
         validate(id_)
 
 
+@pytest.mark.parametrize(
+    'left',
+    (
+        param('@xrandom | @echo', id='xtrig-or-xtrig'),
+        param('@xrandom | task', id='xtrig-or-task'),
+        param('task | @echo', id='task-or-xtrig'),
+        param('@xrandom | foo & bar', id='xtrig-or-complex'),
+        param('@xrandom & bar | foo', id='complex-or-xtrig'),
+    )
+)
+def test_xtrig_or_fails_validation(
+    flow: "Fixture",
+    validate: "Fixture",
+    left: str
+):
+    """Xtriggers cannot be chained with the 'or'
+
+    https://github.com/cylc/cylc-flow/issues/6771
+    https://github.com/cylc/cylc-flow/issues/2712
+    """
+    id_ = flow(
+        {
+            "scheduling": {
+                "initial cycle point": "2024",
+                "xtriggers": {
+                    "xrandom": "xrandom(100)",
+                    "echo": "echo(succeed=True)"
+                },
+                "graph": {"R1": f"{left} => fin"},
+            }
+        }
+    )
+    expected_msg = (
+        "Xtriggers cannot be used in conditional graph expressions:\n")
+    with pytest.raises(WorkflowConfigError, match=expected_msg):
+        validate(id_)
+
+
 def test_special_task_non_word_names(flow: Fixture, validate: Fixture):
     """Test validation of special tasks names with non-word characters"""
     wid = flow({