cloud-storage-mocker 0.0.1a4

Mocker library of Google Cloud Storage with local filesystem mounting.

cloud-storage-mocker

Mocker library of Google Cloud Storage with local filesystem mounting.

Getting started

This library provides patch context manager, which replaces following classes on the google-cloud-storage package:

• Client
• Bucket
• Blob

patch takes a list of Mount objects, which represents a mapping between a bucket name and a local storage. Each mount has Boolean configs readable and writable to control read/write access to the mounted bucket.

A canonical way to use this library is writing unit tests that are working with Google Cloud Storage:

import tempfile

import google.cloud.storage

from cloud_storage_mocker import patch as gcs_patch, Mount

# A pytest test case.
def test_something() -> None:
    # Creates a temporary directory
    # And mounts it to the Cloud Storage bucket "my_bucket"
    with (
        tempfile.TemporaryDirectory() as readable_dir,
        tempfile.TemporaryDirectory() as writable_dir,
        gcs_patch([
            Mount("readable_bucket", readable_dir, readable=True),
            Mount("writable_bucket", writable_dir, writable=True),
        ]),
    ):
        # Reads a blob.
        with open(readable_dir + "/test.txt", "w") as fp:
            fp.write("Hello.")
        blob = google.cloud.storage.Client().bucket("readable_bucket").blob("test.txt")
        assert readable_blob.download_as_text() == "Hello."

        # Writes a blob.
        blob = google.cloud.storage.Client().bucket("writable_bucket").blob("test.txt")
        blob.upload_from_string("World.")
        with open(writable_dir + "/test.txt") as fp:
            assert fp.read() == "World."

Patched methods

Methods below has a specialized behavior to mount the local filesystem.

Other methods are mapped to MagicMock.

• Client()
• Client.bucket()
• Bucket.blob()
• Blob.download_as_text()
• Blob.upload_from_string()

Caution

This library is provided for writing unit tests that work with the Google Cloud Storage client library. DO NOT use this library on any code on the production.