Fix.no validation of outputs from graph singletons

changes.d/6583.fix.md

@@ -0,0 +1 @@
+Fix bug where undefined outputs were missed by validation if no tasks trigger off of them.

cylc/flow/config.py

@@ -99,6 +99,7 @@
     get_trigger_completion_variable_maps,
     trigger_to_completion_variable,
 )
+from cylc.flow.task_qualifiers import TASK_QUALIFIERS
 from cylc.flow.run_modes import RunMode
 from cylc.flow.task_trigger import TaskTrigger, Dependency
 from cylc.flow.taskdef import TaskDef
@@ -1844,6 +1845,7 @@ def generate_triggers(self, lexpression, left_nodes, right, seq,
 
         triggers = {}
         xtrig_labels = set()
+
         for left in left_nodes:
             if left.startswith('@'):
                 xtrig_labels.add(left[1:])
@@ -2266,6 +2268,10 @@ def load_graph(self):
                 parser.workflow_state_polling_tasks)
             self._proc_triggers(parser, seq, task_triggers)
 
+            # Checking for undefined outputs for terminal tasks. Tasks with
+            # dependencies are checked in generate_triggers:
+            self.check_terminal_outputs(parser.terminals)
+
         self.set_required_outputs(task_output_opt)
 
         # Detect use of xtrigger names with '@' prefix (creates a task).
@@ -2278,6 +2284,29 @@ def load_graph(self):
         for tdef in self.taskdefs.values():
             tdef.tweak_outputs()
 
+    def check_terminal_outputs(self, terminals: Iterable[str]) -> None:
+        """Check that task outputs have been registered with tasks.
+
+
+        Where a "terminal output" is an output for a task at the end of a
+        graph string, such as "end" in `start => middle => end`.
+
+        Raises: WorkflowConfigError if a custom output is not defined.
+        """
+        # BACK COMPAT: (On drop 3.7): Can be simplified with walrus :=
+        # if (b := a[1].strip("?")) not in TASK_QUALIFIERS
+        terminal_outputs = [
+            (a[0].strip("!"), a[1].strip("?"))
+            for a in (t.split(':') for t in terminals if ":" in t)
+            if (a[1].strip("?")) not in TASK_QUALIFIERS
+        ]
+
+        for task, output in terminal_outputs:
+            if output not in self.cfg['runtime'][task]['outputs']:
+                raise WorkflowConfigError(
+                    f"Undefined custom output: {task}:{output}"
+                )
+
     def _proc_triggers(self, parser, seq, task_triggers):
         """Define graph edges, taskdefs, and triggers, from graph sections."""
         suicides = 0

cylc/flow/graph_parser.py

@@ -168,6 +168,7 @@ class GraphParser:
     _RE_OFFSET = r'\[[\w\-\+\^:]+\]'
     _RE_QUAL = QUALIFIER + r'[\w\-]+'  # task or fam trigger
     _RE_OPT = r'\??'  # optional output indicator
+    _RE_ANDOR = re.compile(r'\s*[&|]\s*')
 
     REC_QUAL = re.compile(_RE_QUAL)
 
@@ -470,10 +471,23 @@ def parse_graph(self, graph_string: str) -> None:
                 pairs.add((chain[i], chain[i + 1]))
 
         # Get a set of RH nodes which are not at the LH of another pair:
-        terminals = {p[1] for p in pairs}.difference({p[0] for p in pairs})
+        # terminals = {p[1] for p in pairs}.difference({p[0] for p in pairs})
+
+        check_terminals: Dict[str, str] = {}
+        lefts: Set[str] = set()
+        rights: Set[str] = set()
 
         for pair in sorted(pairs, key=lambda p: str(p[0])):
-            self._proc_dep_pair(pair, terminals)
+            self._proc_dep_pair(pair, check_terminals, lefts, rights)
+        self.terminals = rights.difference(lefts)
+        for right in self.terminals:
+            left = check_terminals.get(right)
+            if left:
+                raise GraphParseError(
+                    'Invalid cycle point offsets only on right hand'
+                    ' side of dependency (must be on left hand side):'
+                    f'{left} => {right}'
+                )
 
     @classmethod
     def _report_invalid_lines(cls, lines: List[str]) -> None:
@@ -504,7 +518,9 @@ def _report_invalid_lines(cls, lines: List[str]) -> None:
     def _proc_dep_pair(
         self,
         pair: Tuple[Optional[str], str],
-        terminals: Set[str],
+        check_terminals: Dict[str, str],
+        _lefts: Set[str],
+        _rights: Set[str],
     ) -> None:
         """Process a single dependency pair 'left => right'.
 
@@ -540,12 +556,8 @@ def _proc_dep_pair(
             raise GraphParseError(mismatch_msg.format(right))
 
         # Raise error for cycle point offsets at the end of chains
-        if '[' in right and left and (right in terminals):
-            # This right hand side is at the end of a chain:
-            raise GraphParseError(
-                'Invalid cycle point offsets only on right hand '
-                'side of a dependency (must be on left hand side):'
-                f' {left} => {right}')
+        if '[' in right and left:
+            check_terminals[right] = left
 
         # Split right side on AND.
         rights = right.split(self.__class__.OP_AND)
@@ -566,12 +578,15 @@ def _proc_dep_pair(
             raise GraphParseError(
                 f"Null task name in graph: {left} => {right}")
 
+        _rights.update(*([rights] or []))
+
         for left in lefts:
             # Extract information about all nodes on the left.
-
             if left:
                 info = self.__class__.REC_NODES.findall(left)
                 expr = left
+                for _left in info:
+                    _lefts.add(''.join(_left))
 
             else:
                 # There is no left-hand-side task.

tests/integration/reftests/test_pre_initial.py

@@ -94,7 +94,7 @@ async def test_drop(flow, scheduler, reftest):
     }
 
 
-async def test_over_bracketed(flow, scheduler, reftest):
+async def test_over_bracketed(flow, scheduler, reftest, validate):
     """Test nested conditional simplification for pre-initial cycling."""
     wid = flow({
         'scheduling': {
@@ -108,6 +108,7 @@ async def test_over_bracketed(flow, scheduler, reftest):
             },
         },
     })
+    validate(wid)
     schd = scheduler(wid, paused_start=False)
 
     assert await reftest(schd) == {

tests/integration/test_dbstatecheck.py

@@ -45,7 +45,7 @@ async def checker(
         },
         'runtime': {
             'bad': {'simulation': {'fail cycle points': '1000'}},
-            'output': {'outputs': {'trigger': 'message'}}
+            'output': {'outputs': {'trigger': 'message', 'custom_output': 'foo'}}
         }
     })
     schd: Scheduler = mod_scheduler(wid, paused_start=False)
@@ -119,13 +119,13 @@ def test_output(checker):
             'output',
             '10000101T0000Z',
             "{'submitted': 'submitted', 'started': 'started', 'succeeded': "
-            "'succeeded', 'trigger': 'message'}",
+            "'succeeded', 'trigger': 'message', 'custom_output': 'foo'}",
         ],
         [
             'output',
             '10010101T0000Z',
             "{'submitted': 'submitted', 'started': 'started', 'succeeded': "
-            "'succeeded', 'trigger': 'message'}",
+            "'succeeded', 'trigger': 'message', 'custom_output': 'foo'}",
         ],
     ]
     assert result == expect

tests/integration/test_optional_outputs.py

@@ -288,11 +288,7 @@ def implicit_completion_config(mod_flow, mod_validate):
         },
         'runtime': {
             'root': {
-                'outputs': {
-                    'x': 'xxx',
-                    'y': 'yyy',
-                    'z': 'zzz',
-                }
+                'outputs': {x: f'{x * 3}' for x in 'abcdefghijklxyz'}
             }
         }
     })

tests/integration/validate/test_outputs.py

@@ -276,6 +276,7 @@ def test_completion_expression_invalid(
                 'outputs': {
                     'x': 'xxx',
                     'y': 'yyy',
+                    'file-1': 'asdf'
                 },
             },
         },

tests/unit/test_config.py

@@ -15,12 +15,12 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
-import sys
 from optparse import Values
 from typing import (
     TYPE_CHECKING, Any, Callable, Dict, List, Optional, Tuple, Type)
 import pytest
 import logging
+from textwrap import dedent
 from types import SimpleNamespace
 from contextlib import suppress
 
@@ -47,6 +47,10 @@
 
 from cylc.flow.cycling.iso8601 import ISO8601Point
 
+
+param = pytest.param
+
+
 if TYPE_CHECKING:
     from pathlib import Path
     Fixture = Any
@@ -1175,13 +1179,16 @@ def WorkflowConfig__assert_err_raised():
         WorkflowConfig__assert_err_raised()
 
 
-def test_undefined_custom_output(tmp_flow_config: Callable):
+@pytest.mark.parametrize(
+    'graph', (('foo:x => bar'), ('foo:x'))
+)
+def test_undefined_custom_output(graph: str, tmp_flow_config: Callable):
     """Test error on undefined custom output referenced in graph."""
     id_ = 'custom_out1'
-    flow_file = tmp_flow_config(id_, """
+    flow_file = tmp_flow_config(id_, f"""
     [scheduling]
         [[graph]]
-            R1 = "foo:x => bar"
+            R1 = "{graph}"
     [runtime]
         [[foo, bar]]
     """)
@@ -1700,7 +1707,6 @@ def test_cylc_env_at_parsing(
 
 def test_force_workflow_compat_mode(tmp_path):
     fpath = (tmp_path / 'flow.cylc')
-    from textwrap import dedent
     fpath.write_text(dedent("""
         [scheduler]
             allow implicit tasks = true
@@ -1713,3 +1719,33 @@ def test_force_workflow_compat_mode(tmp_path):
         WorkflowConfig('foo', str(fpath), {})
     # It succeeds with compat mode:
     WorkflowConfig('foo', str(fpath), {}, force_compat_mode=True)
+
+
+@pytest.mark.parametrize(
+    'registered_outputs, tasks_and_outputs, fails',
+    (
+        param([], ['foo:x'], True, id='output-unregistered'),
+        param([], ['foo:x?'], True, id='optional-output-unregistered'),
+        param([], ['foo'], False, id='no-modifier-unregistered'),
+        param(['x'], ['foo:x'], False, id='output-registered'),
+        param([], ['foo:succeed'], False, id='alt-default-ok'),
+        param([], ['foo:failed'], False, id='default-ok'),
+    )
+)
+def test_check_outputs(tmp_path, registered_outputs, tasks_and_outputs, fails):
+    (tmp_path / 'flow.cylc').write_text(dedent("""
+        [scheduler]
+            allow implicit tasks = true
+        [scheduling]
+            [[graph]]
+                R1 = foo
+    """))
+    cfg = WorkflowConfig('', tmp_path / 'flow.cylc', '')
+    cfg.cfg['runtime']['foo']['outputs'] = registered_outputs
+    if fails:
+        with pytest.raises(
+            WorkflowConfigError, match='Undefined custom output'
+        ):
+            cfg.check_terminal_outputs(tasks_and_outputs)
+    else:
+        assert cfg.check_terminal_outputs(tasks_and_outputs) is None

tests/unit/test_graph_parser.py

@@ -27,7 +27,6 @@
 from cylc.flow.graph_parser import GraphParser
 from cylc.flow.task_outputs import (
     TASK_OUTPUT_SUBMITTED,
-    TASK_OUTPUT_SUBMIT_FAILED,
     TASK_OUTPUT_STARTED,
     TASK_OUTPUT_SUCCEEDED,
     TASK_OUTPUT_FAILED
@@ -810,7 +809,6 @@ def test_cannot_be_required():
         gp.parse_graph('a:submit-failed => b')
 
 
-
 @pytest.mark.parametrize(
     'graph, error',
     [
@@ -969,13 +967,13 @@ def test_RHS_AND(graph: str, expected_triggers: Dict[str, List[str]]):
 @pytest.mark.parametrize(
     'args, err',
     (
-        # Error if offset in terminal RHS:
-        param((('a', 'b[-P42M]'), {'b[-P42M]'}), 'Invalid cycle point offset'),
         # No error if offset in NON-terminal RHS:
-        param((('a', 'b[-P42M]'), {}), None),
+        param((('a', 'b[-P42M]'), {}, set(), set()), None),
         # Check the left hand side if this has a non-terminal RHS:
-        param((('a &', 'b[-P42M]'), {}), 'Null task name in graph'),
-    )
+        param(
+            (('a &', 'b[-P42M]'), {}, set(), set()), 'Null task name in graph'
+        ),
+    ),
 )
 def test_proc_dep_pair(args, err):
     """