Implement scheduler command method arg validation.

cylc/flow/command_validation.py

@@ -0,0 +1,257 @@
+# THIS FILE IS PART OF THE CYLC WORKFLOW ENGINE.
+# Copyright (C) NIWA & British Crown (Met Office) & Contributors.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Cylc command argument validation logic."""
+
+
+from typing import (
+    Callable,
+    List,
+    Optional,
+)
+
+from cylc.flow.exceptions import InputError
+from cylc.flow.id import Tokens
+from cylc.flow.task_outputs import TASK_OUTPUT_SUCCEEDED
+from cylc.flow.flow_mgr import FLOW_ALL, FLOW_NEW, FLOW_NONE
+
+
+ERR_OPT_FLOW_VAL = "Flow values must be an integer, or 'all', 'new', or 'none'"
+ERR_OPT_FLOW_INT = "Multiple flow options must all be integer valued"
+ERR_OPT_FLOW_WAIT = (
+    f"--wait is not compatible with --flow={FLOW_NEW} or --flow={FLOW_NONE}"
+)
+
+
+def validate(func: Callable):
+    """Decorate scheduler commands with a callable .validate attribute.
+
+    """
+    # TODO: properly handle "Callable has no attribute validate"?
+    func.validate = globals()[  # type: ignore
+        func.__name__.replace("command", "validate")
+    ]
+    return func
+
+
+def validate_flow_opts(flows: List[str], flow_wait: bool) -> None:
+    """Check validity of flow-related CLI options.
+
+    Note the schema defaults flows to ["all"].
+
+    Examples:
+        Good:
+        >>> validate_flow_opts(["new"], False)
+        >>> validate_flow_opts(["1", "2"], False)
+        >>> validate_flow_opts(["1", "2"], True)
+
+        Bad:
+        >>> validate_flow_opts(["none", "1"], False)
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: ... must all be integer valued
+
+        >>> validate_flow_opts(["cheese", "2"], True)
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: ... or 'all', 'new', or 'none'
+
+        >>> validate_flow_opts(["new"], True)
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: ...
+
+    """
+    for val in flows:
+        val = val.strip()
+        if val in [FLOW_NONE, FLOW_NEW, FLOW_ALL]:
+            if len(flows) != 1:
+                raise InputError(ERR_OPT_FLOW_INT)
+        else:
+            try:
+                int(val)
+            except ValueError:
+                raise InputError(ERR_OPT_FLOW_VAL.format(val))
+
+    if flow_wait and flows[0] in [FLOW_NEW, FLOW_NONE]:
+        raise InputError(ERR_OPT_FLOW_WAIT)
+
+
+def validate_prereqs(prereqs: Optional[List[str]]):
+    """Validate a list of prerequisites, add implicit ":succeeded".
+
+    Comma-separated lists should be split already, client-side.
+
+    Examples:
+        # Set multiple at once:
+        >>> validate_prereqs(['1/foo:bar', '2/foo:baz'])
+        ['1/foo:bar', '2/foo:baz']
+
+        # --pre=all
+        >>> validate_prereqs(["all"])
+        ['all']
+
+        # implicit ":succeeded"
+        >>> validate_prereqs(["1/foo"])
+        ['1/foo:succeeded']
+
+        # Error: invalid format:
+        >>> validate_prereqs(["fish"])
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: ...
+
+        # Error: invalid format:
+        >>> validate_prereqs(["1/foo::bar"])
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: ...
+
+        # Error: "all" must be used alone:
+        >>> validate_prereqs(["all", "2/foo:baz"])
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: ...
+
+    """
+    if prereqs is None:
+        return []
+
+    prereqs2 = []
+    bad: List[str] = []
+    for pre in prereqs:
+        p = validate_prereq(pre)
+        if p is not None:
+            prereqs2.append(p)
+        else:
+            bad.append(pre)
+    if bad:
+        raise InputError(
+            "Use prerequisite format <cycle-point>/<task>:output\n"
+            "\n  ".join(bad)
+        )
+
+    if len(prereqs2) > 1:  # noqa SIM102 (anticipates "cylc set --pre=cycle")
+        if "all" in prereqs:
+            raise InputError("--pre=all must be used alone")
+
+    return prereqs2
+
+
+def validate_prereq(prereq: str) -> Optional[str]:
+    """Return prereq (with :succeeded) if valid, else None.
+
+    Format: cycle/task[:output]
+
+    Examples:
+        >>> validate_prereq('1/foo:succeeded')
+        '1/foo:succeeded'
+
+        >>> validate_prereq('1/foo')
+        '1/foo:succeeded'
+
+        >>> validate_prereq('all')
+        'all'
+
+        # Error:
+        >>> validate_prereq('fish')
+
+    """
+    try:
+        tokens = Tokens(prereq, relative=True)
+    except ValueError:
+        return None
+    if (
+        tokens["cycle"] == prereq
+        and prereq != "all"
+    ):
+        # Error: --pre=<word> other than "all"
+        return None
+
+    if prereq != "all" and tokens["task_sel"] is None:
+        prereq += f":{TASK_OUTPUT_SUCCEEDED}"
+
+    return prereq
+
+
+def validate_outputs(outputs: Optional[List[str]]):
+    """Validate outputs.
+
+    Comma-separated lists should be split already, client-side.
+
+    Examples:
+        Good:
+        >>> validate_outputs(['a', 'b'])
+        ['a', 'b']
+
+        >>> validate_outputs(["required"])  # "required" is explicit default
+        []
+
+        Bad:
+        >>> validate_outputs(["required", "a"])
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: --out=required must be used alone
+
+        >>> validate_outputs(["waiting"])
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: Tasks cannot be set to waiting...
+
+    """
+    # If "required" is explicit just ditch it (same as the default)
+    if not outputs or outputs == ["required"]:
+        return []
+
+    if "required" in outputs:
+        raise InputError("--out=required must be used alone")
+
+    if "waiting" in outputs:
+        raise InputError(
+            "Tasks cannot be set to waiting. Use trigger to re-run tasks."
+        )
+
+    return outputs
+
+
+def validate_consistency(
+    outputs: Optional[List[str]],
+    prereqs: Optional[List[str]]
+) -> None:
+    """Check global option consistency
+
+    Examples:
+        >>> validate_consistency(["a"], None)  # OK
+
+        >>> validate_consistency(None, ["1/a:failed"])  #OK
+
+        >>> validate_consistency(["a"], ["1/a:failed"])
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: ...
+
+    """
+    if outputs and prereqs:
+        raise InputError("Use --prerequisite or --output, not both.")
+
+
+def validate_set(
+    tasks: List[str],
+    flow: List[str],
+    outputs: Optional[List[str]] = None,
+    prerequisites: Optional[List[str]] = None,
+    flow_wait: bool = False,
+    flow_descr: Optional[str] = None
+) -> None:
+    """Validate args of the scheduler "command_set" method.
+
+    Raise InputError if validation fails.
+    """
+    validate_consistency(outputs, prerequisites)
+    outputs = validate_outputs(outputs)
+    prerequisites = validate_prereqs(prerequisites)
+    validate_flow_opts(flow, flow_wait)

cylc/flow/flow_mgr.py

@@ -20,7 +20,6 @@
 import datetime
 
 from cylc.flow import LOG
-from cylc.flow.exceptions import InputError
 
 
 if TYPE_CHECKING:
@@ -32,13 +31,6 @@
 FLOW_NEW = "new"
 FLOW_NONE = "none"
 
-# For flow-related CLI options:
-ERR_OPT_FLOW_VAL = "Flow values must be an integer, or 'all', 'new', or 'none'"
-ERR_OPT_FLOW_INT = "Multiple flow options must all be integer valued"
-ERR_OPT_FLOW_WAIT = (
-    f"--wait is not compatible with --flow={FLOW_NEW} or --flow={FLOW_NONE}"
-)
-
 
 def add_flow_opts(parser):
     parser.add_option(
@@ -63,27 +55,6 @@ def add_flow_opts(parser):
     )
 
 
-def validate_flow_opts(options):
-    """Check validity of flow-related CLI options."""
-    if options.flow is None:
-        # Default to all active flows
-        options.flow = [FLOW_ALL]
-
-    for val in options.flow:
-        val = val.strip()
-        if val in [FLOW_NONE, FLOW_NEW, FLOW_ALL]:
-            if len(options.flow) != 1:
-                raise InputError(ERR_OPT_FLOW_INT)
-        else:
-            try:
-                int(val)
-            except ValueError:
-                raise InputError(ERR_OPT_FLOW_VAL.format(val))
-
-    if options.flow_wait and options.flow[0] in [FLOW_NEW, FLOW_NONE]:
-        raise InputError(ERR_OPT_FLOW_WAIT)
-
-
 def stringify_flow_nums(flow_nums: Set[int], full: bool = False) -> str:
     """Return a string representation of a set of flow numbers
 

cylc/flow/network/multi.py

@@ -19,6 +19,30 @@
 
 from cylc.flow.async_util import unordered_map
 from cylc.flow.id_cli import parse_ids_async
+from cylc.flow.exceptions import InputError
+
+
+def print_response(multi_results):
+    """Print server mutation response to stdout.
+
+    The response will be either:
+        - (False, argument-validation-error)
+        - (True, ID-of-queued-command)
+
+    Raise InputError if validation failed.
+
+    """
+    for multi_result in multi_results:
+        for _cmd, results in multi_result.items():
+            for result in results.values():
+                for wf_res in result:
+                    wf_id = wf_res["id"]
+                    response = wf_res["response"]
+                    if not response[0]:
+                        # Validation failure
+                        raise InputError(response[1])
+                    else:
+                        print(f"{wf_id}: command {response[1]} queued")
 
 
 def call_multi(*args, **kwargs):
@@ -107,4 +131,4 @@
 
 
 def _report(_):
-    print('Command submitted; the scheduler will log any problems.')
+    pass

cylc/flow/network/resolvers.py

@@ -42,6 +42,7 @@
     EDGES, FAMILY_PROXIES, TASK_PROXIES, WORKFLOW,
     DELTA_ADDED, create_delta_store
 )
+from cylc.flow.exceptions import InputError
 from cylc.flow.id import Tokens
 from cylc.flow.network.schema import (
     DEF_TYPES,
@@ -740,10 +741,19 @@
             return method(**kwargs)
 
         try:
-            self.schd.get_command_method(command)
+            meth = self.schd.get_command_method(command)
         except AttributeError:
             raise ValueError(f"Command '{command}' not found")
 
+        # If meth has a command validation function, call it.
+        try:
+            # TODO: properly handle "Callable has no attribute validate"?
+            meth.validate(**kwargs)  # type: ignore
+        except AttributeError:
+            LOG.debug(f"No command validation for {command}")
+        except InputError as exc:
+            return (False, str(exc))
+
         # Queue the command to the scheduler, with a unique command ID
         cmd_uuid = str(uuid4())
         LOG.info(f"{log1} ID={cmd_uuid}\n{log2}")

cylc/flow/scheduler.py

@@ -53,6 +53,7 @@
 )
 from cylc.flow.broadcast_mgr import BroadcastMgr
 from cylc.flow.cfgspec.glbl_cfg import glbl_cfg
+from cylc.flow import command_validation
 from cylc.flow.config import WorkflowConfig
 from cylc.flow.data_store_mgr import DataStoreMgr
 from cylc.flow.id import Tokens
@@ -2146,6 +2147,7 @@ def command_force_trigger_tasks(
         return self.pool.force_trigger_tasks(
             tasks, flow, flow_wait, flow_descr)
 
+    @command_validation.validate
     def command_set(
         self,
         tasks: List[str],