Summary:

When autorest is executed with `two times, the generated init.py file in the namespace directory does not have the expected content and differs from the content which was generated in the first time.

Test Environment:

• Windows 10
• AutoRest code generation utility [cli version: 3.0.6187; node: v12.16.1, max-memory: 8192 gb]
• Loading AutoRest extension '@autorest/python' (5.0.0-preview.8->5.0.0-preview.8) (--use=@autorest/[email protected] option was used)

Details

1. Get petstore.yaml file from https://github.com/Azure/autorest/blob/master/Samples/openapi-v3/1a-code-generation-minimal/petstore.yaml

2. Execute the following command:
   autorest --input-file=petstore.yaml --python --output-folder=petstore --namespace=azure.mgmt.petstore --azure-arm=true --use=@autorest/[email protected] --package-version=0.2 --basic-setup-py=true

The content of the petstore/azure/mgmt/petstore/__init__.py file is:

# coding=utf-8
# --------------------------------------------------------------------------
# Code generated by Microsoft (R) AutoRest Code Generator (autorest: 3.0.6282, generator: {generator})
# Changes may cause incorrect behavior and will be lost if the code is regenerated.
# --------------------------------------------------------------------------

from ._swagger_petstore import SwaggerPetstore
from ._version import VERSION

__version__ = VERSION
__all__ = ['SwaggerPetstore']

try:
    from ._patch import patch_sdk
    patch_sdk()
except ImportError:
    pass

4. Execute the same command again. The content has changed:

__path__ = __import__('pkgutil').extend_path(__path__, __name__)  # type: ignore-----------
# Code generated by Microsoft (R) AutoRest Code Generator (autorest: 3.0.6282, generator: {generator})
# Changes may cause incorrect behavior and will be lost if the code is regenerated.
# --------------------------------------------------------------------------

from ._swagger_petstore import SwaggerPetstore
from ._version import VERSION

__version__ = VERSION
__all__ = ['SwaggerPetstore']

try:
    from ._patch import patch_sdk
    patch_sdk()
except ImportError:
    pass

One can see that the first line has been overwritten.

Additional information

• I have tried with various OpenAPI files and with different options (with and without --basic-setup-py option, the result is the same.
• I have tried with and without --clear-output-folder=true, the result is the same.
• If I manually delete the output folder, the next generation is good again. (However, this is tricky because if VS Code was open, despite the folder deletion, the next generation was wrong again. This is magic, I know, could not find the real root cause here.)
• If I delete only the __init__.py file, the next generation is wrong again!
• No other __init__.py file has the same issue, only the one which is in the namespace folder.