How To Mock Google Cloud Storage Bucket And Link It To Client Object?

I have a function in cloud run and trying to test using mock in Python. How can I mock bucket with a blob and attach it to storage client? Assert fails and it's displaying output i

Solution 1:

    def test_read_sql(self):
        storage_client = mock.create_autospec(storage.Client)
        mock_bucket = mock.create_autospec(storage.Bucket)
        mock_blob = mock.create_autospec(storage.Blob)
        mock_bucket.return_value = mock_blob
        storage_client.get_bucket.return_value = mock_bucket
        mock_bucket.get_blob.return_value = mock_blob
        mock_blob.download_as_string.return_value.decode.return_value = "file_content"
        read_content = main.read_sql(storage_client, 'test_bucket', 'test_blob')
        assert read_content == 'file_content'