ansible/test/integration/targets/rds_instance/tasks/credential_tests.yml

---
- name: test without credentials
  rds_instance:
    db_instance_identifier: test-rds-instance
  register: result
  ignore_errors: yes

- assert:
    that:
      - result.failed
      - 'result.msg == "The rds_instance module requires a region and none was found in configuration, environment variables or module parameters"'

- name: test without credentials
  rds_instance:
    db_instance_identifier: test-rds-instance
    region: us-east-1
  register: result
  ignore_errors: yes

- assert:
    that:
      - result.failed
      - '"Unable to locate credentials" in result.msg'

- name: test with invalid credentials
  rds_instance:
    db_instance_identifier: test-rds-instance
    region: us-east-1
    profile: doesnotexist
  register: result
  ignore_errors: yes

- assert:
    that:
      - result.failed
      - 'result.msg == "The config profile (doesnotexist) could not be found"'