[TESTS] Add tests for the s3 module

pyproject.toml

@@ -25,6 +25,7 @@ pygments = "^2.19.1"
 [tool.poetry.group.dev.dependencies]
 bandit = "^1.8.3"
 black = "^25.1.0"
+moto = "^5.1.9"
 
 [tool.poetry.group.docs.dependencies]
 sphinx-rtd-theme = "^3.0.2"

tests/s3/conftest.py

@@ -0,0 +1,46 @@
+import pytest
+from pathlib import Path
+from moto import mock_aws
+from hashlib import md5, sha256
+import boto3
+
+
+# Dummy CName replacement
+class DummyCName:
+    def __init__(self, cname):  # pylint: disable=unused-argument
+        self.platform = "aws"
+        self.arch = "amd64"
+        self.version = "1234.1"
+        self.commit_id = "abc123"
+
+
+# Helpers to compute digests for fake files
+def dummy_digest(data: bytes, algo: str) -> str:
+    """
+    Dummy for file_digest() to compute hashes for in-memory byte streams
+    """
+    content = data.read()
+    data.seek(0)  # Reset byte cursor to start for multiple uses
+
+    if algo == "md5":
+        return md5(content)  # nosec B324
+    elif algo == "sha256":
+        return sha256(content)
+    else:
+        raise ValueError(f"Unsupported algo: {algo}")
+
+
+@pytest.fixture(autouse=True)
+def s3_setup(tmp_path, monkeypatch):
+    """
+    Provides a clean S3 setup for each test.
+    """
+    with mock_aws():
+        s3 = boto3.resource("s3", region_name="us-east-1")
+        bucket_name = "test-bucket"
+        s3.create_bucket(Bucket=bucket_name)
+
+        monkeypatch.setattr("gardenlinux.s3.s3_artifacts.CName", DummyCName)
+        monkeypatch.setattr("gardenlinux.s3.s3_artifacts.file_digest", dummy_digest)
+
+        yield s3, bucket_name, tmp_path