Add architecture unit tests

tests/unit/test_architecture.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+from unittest.mock import patch
+
+from architecture import is_wrong_architecture
+
+TEST_MANIFEST = """
+    bases:
+        - architectures:
+            - {arch}
+          channel: '22.04'
+          name: ubuntu
+"""
+
+
+def test_wrong_architecture_file_not_found():
+    """Tests if the function returns False when the charm file doesn't exist."""
+    with (
+        patch("os.environ", return_value={"CHARM_DIR": "/tmp"}),
+        patch("pathlib.Path.exists", return_value=False),
+    ):
+        assert not is_wrong_architecture()
+
+
+def test_wrong_architecture_amd64():
+    """Tests if the function correctly identifies arch when charm is AMD."""
+    with (
+        patch("os.environ", return_value={"CHARM_DIR": "/tmp"}),
+        patch("pathlib.Path.exists", return_value=True),
+        patch("pathlib.Path.read_text", return_value=TEST_MANIFEST.format(arch="amd64")),
+        patch("platform.machine") as machine,
+    ):
+        machine.return_value = "x86_64"
+        assert not is_wrong_architecture()
+        machine.return_value = "aarch64"
+        assert is_wrong_architecture()
+
+
+def test_wrong_architecture_arm64():
+    """Tests if the function correctly identifies arch when charm is ARM."""
+    with (
+        patch("os.environ", return_value={"CHARM_DIR": "/tmp"}),
+        patch("pathlib.Path.exists", return_value=True),
+        patch("pathlib.Path.read_text", return_value=TEST_MANIFEST.format(arch="arm64")),
+        patch("platform.machine") as machine,
+    ):
+        machine.return_value = "x86_64"
+        assert is_wrong_architecture()
+        machine.return_value = "aarch64"
+        assert not is_wrong_architecture()