Check run name as well as workflow name in Cylc install

changes.d/6264.fix.md

@@ -0,0 +1 @@
+Fix bug where  failed to prevent invalid run names.

cylc/flow/install.py

@@ -285,13 +285,18 @@ def install_workflow(
     source = Path(expand_path(source)).resolve()
     if not workflow_name:
         workflow_name = get_source_workflow_name(source)
-    validate_workflow_name(workflow_name, check_reserved_names=True)
     if run_name is not None:
+        validate_workflow_name(
+            workflow_name + '/' + run_name,
+            being_validated='workflow and run'
+        )
         if len(Path(run_name).parts) != 1:
             raise WorkflowFilesError(
                 f'Run name cannot be a path. (You used {run_name})'
             )
         check_reserved_dir_names(run_name)
+    else:
+        validate_workflow_name(workflow_name, check_reserved_names=True)
     validate_source_dir(source, workflow_name)
     run_path_base = Path(get_workflow_run_dir(workflow_name))
     relink, run_num, rundir = get_run_dir_info(

cylc/flow/workflow_files.py

@@ -42,6 +42,7 @@
     NoReturn,
     Type,
 )
+from typing_extensions import Literal
 
 import cylc.flow.flags
 from cylc.flow import LOG
@@ -831,31 +832,36 @@ def check_deprecation(path, warn=True, force_compat_mode=False):
 
 
 def validate_workflow_name(
-    name: str, check_reserved_names: bool = False
+    name: str,
+    check_reserved_names: bool = False,
+    being_validated: Literal['workflow', 'workflow and run'] = 'workflow'
 ) -> None:
-    """Check workflow name/ID is valid and not an absolute path.
+    """Check workflow/run name/ID is valid and not an absolute path.
 
     Args:
         name: Workflow name or ID.
         check_reserved_names: If True, check that the name does not
             contain reserved dir names.
+        being_validated: A description of whether a workflow or
+            workflow and a run name together are being validated.
 
     Raise WorkflowFilesError if not valid.
     """
     is_valid, message = WorkflowNameValidator.validate(name)
     if not is_valid:
         raise WorkflowFilesError(
-            f"invalid workflow name '{name}' - {message}"
+            f"invalid {being_validated} name '{name}' - {message}"
         )
     if os.path.isabs(name):
         raise WorkflowFilesError(
-            f"workflow name cannot be an absolute path: {name}"
+            f"{being_validated.capitalize()}"
+            f' name cannot be an absolute path: {name}'
         )
     name = os.path.normpath(name)
     if name.startswith(os.curdir):
         raise WorkflowFilesError(
-            "Workflow name cannot be a path that points to the cylc-run "
-            "directory or above"
+            f"{being_validated.capitalize()} name cannot be a"
+            " path that points to the cylc-run directory or above"
         )
     if check_reserved_names:
         check_reserved_dir_names(name)

tests/unit/test_install.py

@@ -542,3 +542,19 @@ def test_validate_source_dir(tmp_run_dir: Callable, tmp_src_dir: Callable):
     with pytest.raises(WorkflowFilesError) as exc_info:
         validate_source_dir(src_dir, 'ajay')
     assert "exists in source directory" in str(exc_info.value)
+
+
+def test_install_workflow_failif_bad_name(tmp_src_dir):
+    """If a run_name is given validate_workflow_name is called on
+    the workflow and the run name in combination.
+    """
+    src_dir: Path = tmp_src_dir('ludlow')
+    # It only has a workflow name:
+    with pytest.raises(WorkflowFilesError, match='can only contain'):
+        install_workflow(src_dir, workflow_name='foo?')
+    # It only has a run name:
+    with pytest.raises(WorkflowFilesError, match='can only contain'):
+        install_workflow(src_dir, run_name='foo?')
+    # It has a legal workflow name, but an invalid run name:
+    with pytest.raises(WorkflowFilesError, match='can only contain'):
+        install_workflow(src_dir, workflow_name='foo', run_name='bar?')