[stable-2.10] ansible-test - Fix traceback in validate-modules test.

(cherry picked from commit 41ee4a5b12)

Co-authored-by: Matt Clay <matt@mystile.com>

changelogs/fragments/ansible-test-validate-modules-no-callable.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - ansible-test - Fix traceback in the ``validate-modules`` sanity test when testing an Ansible module without any callables.

test/integration/targets/ansible-test/ansible_collections/ns/col/plugins/modules/no_callable.py

@@ -0,0 +1,23 @@
+#!/usr/bin/python
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+DOCUMENTATION = '''
+module: no_callable
+short_description: No callale test module
+description: No callable test module.
+author:
+  - Ansible Core Team
+'''
+
+EXAMPLES = '''#'''
+RETURN = ''''''
+
+from ansible.module_utils.basic import AnsibleModule
+
+
+if __name__ == '__main__':
+    module = AnsibleModule(argument_spec=dict())
+    module.exit_json()

test/lib/ansible_test/_data/sanity/validate-modules/validate_modules/main.py

@@ -583,7 +583,7 @@ class ModuleValidator(Validator):
             if isinstance(child, (ast.FunctionDef, ast.ClassDef)):
                 linenos.append(child.lineno)
 
-        return min(linenos)
+        return min(linenos) if linenos else None
 
     def _find_main_call(self, look_for="main"):
         """ Ensure that the module ends with:
@@ -2192,7 +2192,7 @@ class ModuleValidator(Validator):
             main = self._find_main_call()
             self._find_module_utils(main)
             self._find_has_import()
-            first_callable = self._get_first_callable()
+            first_callable = self._get_first_callable() or 1000000  # use a bogus "high" line number if no callable exists
             self._ensure_imports_below_docs(doc_info, first_callable)
             self._check_for_subprocess()
             self._check_for_os_call()