testing: Enable automatic selection of the OS image based on the test and filename prefix, addressing an issue in the development environment.

For example, when using VSCode with pytest, test autodiscovery triggers pytest_generate_tests(), adding all images to each test case. This causes issues, as Linux tests end up being executed with Windows and Mac images, and vice versa.

.github/workflows/test.yaml

@@ -25,10 +25,13 @@ jobs:
 
     - name: Download images
       run: |
+        mkdir test_images
+        cd test_images
         curl -sLO "https://downloads.volatilityfoundation.org/volatility3/images/linux-sample-1.bin.gz"
         gunzip linux-sample-1.bin.gz
         curl -sLO "https://downloads.volatilityfoundation.org/volatility3/images/win-xp-laptop-2005-06-25.img.gz"
         gunzip win-xp-laptop-2005-06-25.img.gz
+        cd -
 
     - name: Download and Extract symbols
       run: |
@@ -39,13 +42,12 @@ jobs:
 
     - name: Testing...
       run: |
-        pytest ./test/test_volatility.py --volatility=vol.py --image win-xp-laptop-2005-06-25.img -k test_windows -v
-        pytest ./test/test_volatility.py --volatility=vol.py --image linux-sample-1.bin -k test_linux -v
+        pytest ./test/test_volatility.py --volatility=vol.py --image-dir=./test_images -k test_windows -v
+        pytest ./test/test_volatility.py --volatility=vol.py --image-dir=./test_images -k test_linux -v
 
     - name: Clean up post-test
       run: |
-        rm -rf *.bin
-        rm -rf *.img
+        rm -rf test_images
         cd volatility3/symbols
         rm -rf linux
         rm -rf linux.zip

test/conftest.py

@@ -35,16 +35,39 @@ def pytest_addoption(parser):
 def pytest_generate_tests(metafunc):
     """Parameterize tests based on image names"""
 
-    images = metafunc.config.getoption("image")
+    images = metafunc.config.getoption("image").copy()
     for image_dir in metafunc.config.getoption("image_dir"):
-        images = images + [
-            os.path.join(image_dir, dir) for dir in os.listdir(image_dir)
+        images += [
+            os.path.join(image_dir, dir_name) for dir_name in os.listdir(image_dir)
         ]
 
-    # tests with "image" parameter are run against images
+    # tests with "image" parameter are run against image
     if "image" in metafunc.fixturenames:
+        filtered_images = []
+        ids = []
+        for image in images:
+            image_base = os.path.basename(image)
+            test_name = metafunc.definition.originalname
+            if test_name.startswith("test_windows_") and not image_base.startswith(
+                "win-"
+            ):
+                continue
+            elif test_name.startswith("test_linux_") and not image_base.startswith(
+                "linux-"
+            ):
+                continue
+            elif test_name.startswith("test_mac_") and not image_base.startswith(
+                "mac-"
+            ):
+                continue
+
+            filtered_images.append(image)
+            ids.append(image_base)
+
         metafunc.parametrize(
-            "image", images, ids=[os.path.basename(image) for image in images]
+            "image",
+            filtered_images,
+            ids=ids,
         )