fix(workflows): reject non-list input 'enum' instead of crashing

src/specify_cli/workflows/engine.py

@@ -193,6 +193,20 @@ def validate_workflow(definition: WorkflowDefinition) -> list[str]:
                     f"Must be 'string', 'number', or 'boolean'."
                 )
 
+            # ``enum`` must be a list. Checked here — not only via the
+            # ``_coerce_input`` call below — because that call is reached only
+            # when a ``default`` is present, and the ``integration: auto`` case
+            # strips ``enum`` before coercing; a scalar/string ``enum`` on an
+            # input with no default (or the auto-integration default) would
+            # otherwise slip through here and then crash ``_resolve_inputs`` with
+            # a raw ``TypeError`` at run time. ``None`` means "no enum".
+            enum_values = input_def.get("enum")
+            if enum_values is not None and not isinstance(enum_values, list):
+                errors.append(
+                    f"Input {input_name!r} has invalid 'enum': must be a list, "
+                    f"got {type(enum_values).__name__}."
+                )
+
             # Validate the default eagerly so authoring mistakes (e.g. a
             # default not in the declared enum, or a non-numeric default for
             # a number input) surface at install/validation time instead of
@@ -201,13 +215,28 @@ def validate_workflow(definition: WorkflowDefinition) -> list[str]:
             # enum-membership check is exempted for that exact case — the
             # declared type is still enforced (e.g. ``type: number`` paired
             # with ``default: "auto"`` is still rejected).
+            enum_is_valid = enum_values is None or isinstance(enum_values, list)
             if "default" in input_def:
                 default_value = input_def["default"]
                 is_auto_integration = (
                     input_name == "integration" and default_value == "auto"
                 )
+                # Strip ``enum`` from the definition handed to ``_coerce_input``
+                # when either:
+                #   * this is the auto-integration sentinel (enum-membership is
+                #     a runtime concern, exempted for ``"auto"``), or
+                #   * the ``enum`` is malformed (non-list) and already reported
+                #     above — leaving it in would make ``_coerce_input`` re-raise
+                #     the same enum-shape error re-framed as an "invalid default"
+                #     (a confusing duplicate).
+                # Removing *only* ``enum`` (rather than skipping the check
+                # entirely) preserves the default's type validation: a
+                # ``type: string`` input with ``default: 5, enum: 5`` still
+                # reports the wrong-typed default alongside the enum error,
+                # instead of hiding it.
+                strip_enum = (is_auto_integration or not enum_is_valid)
                 validation_input_def: dict[str, Any] = input_def
-                if is_auto_integration and "enum" in input_def:
+                if strip_enum and "enum" in input_def:
                     validation_input_def = {
                         key: value
                         for key, value in input_def.items()
@@ -1368,11 +1397,18 @@ def _resolve_inputs(
             # definition (``string`` rejects non-strings, ``number`` rejects
             # bools and uncoercible values, ``boolean`` rejects non-bools),
             # so ill-typed values still fail fast here.
+            #
+            # ``execute()`` accepts unvalidated definitions, so a malformed
+            # (non-list) ``enum`` can reach here. Only strip a *list* ``enum``:
+            # a scalar/string ``enum`` must stay in the definition so
+            # ``_coerce_input`` raises the clean shape ``ValueError`` instead of
+            # being silently exempted by the ``auto`` membership skip (which
+            # would otherwise let ``enum: 5`` resolve successfully).
             coerce_input_def = input_def
             if (
                 name == "integration"
                 and value == "auto"
-                and "enum" in input_def
+                and isinstance(input_def.get("enum"), list)
             ):
                 coerce_input_def = {
                     key: val
@@ -1418,6 +1454,22 @@ def _coerce_input(
         input_type = input_def.get("type", "string")
         enum_values = input_def.get("enum")
 
+        # ``enum`` must be a list. A scalar (``enum: 5``, ``enum: true``) makes
+        # the ``value not in enum_values`` membership test below raise a raw
+        # ``TypeError`` ("argument of type 'int' is not ... iterable"), which
+        # escapes ``validate_workflow``'s ``except ValueError`` and breaks its
+        # "return errors, never raise" contract — and crashes ``_resolve_inputs``
+        # outright at run time. A bare string is just as wrong: ``value in "abc"``
+        # is a silent substring/character test, not enum membership. Require a
+        # list so both forms fail fast with a clear message. ``None`` means "no
+        # enum" and is left alone.
+        if enum_values is not None and not isinstance(enum_values, list):
+            msg = (
+                f"Input {name!r} has invalid 'enum': must be a list, got "
+                f"{type(enum_values).__name__}."
+            )
+            raise ValueError(msg)
+
         if input_type == "number":
             # Reject bools explicitly: ``bool`` is a subclass of ``int`` so
             # ``float(True)`` succeeds and would silently coerce a YAML

tests/test_workflows.py

@@ -3950,6 +3950,167 @@ def test_validate_workflow_rejects_non_string_default_for_string_type(self):
         errors = validate_workflow(definition)
         assert any("invalid default" in e for e in errors), errors
 
+    def test_validate_workflow_rejects_scalar_enum(self):
+        """A non-list ``enum`` (``enum: 5``) must be reported as a validation
+        error, not crash ``validate_workflow`` with a raw ``TypeError`` from the
+        ``value not in enum_values`` membership test."""
+        from specify_cli.workflows.engine import WorkflowDefinition, validate_workflow
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "scalar-enum"
+  name: "Scalar Enum"
+  version: "1.0.0"
+inputs:
+  scope:
+    type: string
+    enum: 5
+steps:
+  - id: noop
+    type: gate
+    message: "noop"
+    options: [approve]
+""")
+        errors = validate_workflow(definition)
+        assert any("invalid 'enum'" in e and "must be a list" in e for e in errors), errors
+
+    def test_validate_workflow_rejects_string_enum(self):
+        """A bare-string ``enum`` (``enum: abc``) must be rejected too — otherwise
+        ``value in "abc"`` is a silent substring/character test, not enum
+        membership."""
+        from specify_cli.workflows.engine import WorkflowDefinition, validate_workflow
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "string-enum"
+  name: "String Enum"
+  version: "1.0.0"
+inputs:
+  scope:
+    type: string
+    default: "a"
+    enum: "abc"
+steps:
+  - id: noop
+    type: gate
+    message: "noop"
+    options: [approve]
+""")
+        errors = validate_workflow(definition)
+        assert any("invalid 'enum'" in e and "must be a list" in e for e in errors), errors
+        # The malformed enum is reported once — not re-framed a second time as an
+        # "invalid default" by the default-coercion path.
+        assert sum("invalid 'enum'" in e for e in errors) == 1, errors
+
+    def test_resolve_inputs_rejects_scalar_enum_at_runtime(self, project_dir):
+        """A non-list ``enum`` must raise a clean ``ValueError`` (not a raw
+        ``TypeError``) when a provided value is coerced at run time, since
+        ``execute`` does not auto-validate the definition first."""
+        from specify_cli.workflows.engine import WorkflowEngine, WorkflowDefinition
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "runtime-scalar-enum"
+  name: "Runtime Scalar Enum"
+  version: "1.0.0"
+inputs:
+  scope:
+    type: string
+    enum: 5
+""")
+        engine = WorkflowEngine(project_dir)
+        with pytest.raises(ValueError, match="invalid 'enum'"):
+            engine._resolve_inputs(definition, {"scope": "bar"})
+
+    def test_validate_workflow_accepts_list_enum(self):
+        """A well-formed list ``enum`` must still validate cleanly and continue to
+        check the default against enum membership."""
+        from specify_cli.workflows.engine import WorkflowDefinition, validate_workflow
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "list-enum"
+  name: "List Enum"
+  version: "1.0.0"
+inputs:
+  scope:
+    type: string
+    default: "full"
+    enum: ["full", "backend-only"]
+steps:
+  - id: noop
+    type: gate
+    message: "noop"
+    options: [approve]
+""")
+        errors = validate_workflow(definition)
+        assert not any("enum" in e for e in errors), errors
+
+    def test_validate_workflow_scalar_enum_still_reports_bad_default_type(self):
+        """A malformed ``enum`` must not mask an independent default type error.
+
+        With ``type: string`` and ``default: 5`` alongside ``enum: 5``, the
+        malformed enum is reported once *and* the wrong-typed default is still
+        surfaced — stripping only ``enum`` from the coercion input preserves the
+        default's type validation instead of skipping it entirely."""
+        from specify_cli.workflows.engine import WorkflowDefinition, validate_workflow
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "scalar-enum-bad-default"
+  name: "Scalar Enum Bad Default"
+  version: "1.0.0"
+inputs:
+  scope:
+    type: string
+    default: 5
+    enum: 5
+steps:
+  - id: noop
+    type: gate
+    message: "noop"
+    options: [approve]
+""")
+        errors = validate_workflow(definition)
+        # The enum shape is reported exactly once...
+        assert sum("invalid 'enum'" in e for e in errors) == 1, errors
+        # ...and the independent wrong-typed default is still surfaced.
+        assert any(
+            "invalid default" in e and "expected a string" in e for e in errors
+        ), errors
+
+    def test_resolve_inputs_auto_integration_rejects_scalar_enum(self, project_dir):
+        """The ``integration: auto`` runtime exemption must not swallow a
+        malformed ``enum``.
+
+        ``_resolve_inputs`` strips ``enum`` before coercing the ``auto``
+        sentinel so a workflow listing specific integrations doesn't crash on
+        ``"auto"``. But that strip must apply only to a *list* ``enum`` — a
+        scalar ``enum: 5`` must still reach ``_coerce_input`` and raise a clean
+        ``ValueError``, not be silently exempted and resolve successfully."""
+        from specify_cli.workflows.engine import WorkflowEngine, WorkflowDefinition
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "auto-integration-scalar-enum"
+  name: "Auto Integration Scalar Enum"
+  version: "1.0.0"
+inputs:
+  integration:
+    type: string
+    default: "auto"
+    enum: 5
+""")
+        engine = WorkflowEngine(project_dir)
+        with pytest.raises(ValueError, match="invalid 'enum'"):
+            engine._resolve_inputs(definition, {})
+
     def test_while_loop_condition_reads_latest_iteration(self, project_dir):
         """Regression: while-loop condition must see updated step output
         from the most recent iteration, not stale iteration-0 data.