Detect game specific compatibility tool mappings

The Steam Play manifest in `appinfo.vdf` contains game specific
compatibility tool mappings. For example, at the time of writing
Cyberpunk 2077 is set to use Proton Experimental by default to enable
DualSense support.

Update Protontricks to support detect these compatibility tool mappings,
as otherwise Protontricks might use a wrong Proton version or fail to
select a Proton version entirely.

Fixes #267

CHANGELOG.md

@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Fixed
  - Fix Protontricks not recognizing supported Steam Runtime installation due to changed name
+ - Fix Protontricks not recognizing default Proton installation for games with different Proton preselected by Valve testing
 
 ## [1.10.5] - 2023-09-05
 ### Fixed

src/protontricks/steam.py

@@ -624,6 +624,16 @@ def _get_tool_app(compat_tool_name, steam_apps, steam_play_manifest):
         # App ID was most likely not provided
         app_section = None
 
+    try:
+        manifest_app_compat_section = next(
+            entry for mapping_appid, entry in
+            steam_play_manifest["appinfo"]["extended"]["app_mappings"].items()
+            if int(mapping_appid) == appid
+        )
+    except StopIteration:
+        # App doesn't have a default compatibility tool mapping
+        manifest_app_compat_section = None
+
     # ToolMapping seems to be used in older Steam beta releases
     try:
         tool_mapping = (
@@ -679,7 +689,19 @@ def _get_tool_app(compat_tool_name, steam_apps, steam_play_manifest):
             )
             potential_names.append(recommended_runtime)
 
-    # Global user settings have the 3rd highest priority
+    # Game specific default compatibility tool mapping in Steam Play 2.0
+    # manifest has the 3rd highest priority
+    if manifest_app_compat_section:
+        if "tool" in manifest_app_compat_section:
+            tool = manifest_app_compat_section["tool"]
+            logger.info(
+                "App has default compatibility tool mapping in the Steam Play "
+                "manifest: %s",
+                tool
+            )
+            potential_names.append(tool)
+
+    # Global user settings have the 4th highest priority
     if compat_tool_mapping.get("0", {}).get("name"):
         tool_name = compat_tool_mapping["0"]["name"]
         logger.info(
@@ -689,7 +711,7 @@ def _get_tool_app(compat_tool_name, steam_apps, steam_play_manifest):
         )
         potential_names.append(tool_name)
 
-    # Legacy user settings (ToolMapping) have the 4th highest priority
+    # Legacy user settings (ToolMapping) have the 5th highest priority
     if tool_mapping.get(str(appid), {}).get("name", {}):
         tool_name = tool_mapping[str(appid)]["name"]
         logger.info(

tests/conftest.py

@@ -352,6 +352,34 @@ def func(proton_app, compat_tool_name, aliases=None):
     return func
 
 
+@pytest.fixture(scope="function")
+def appinfo_app_mapping_factory(appinfo_factory, steam_dir):
+    """
+    Factory function to add Steam app specific compat tool app mappings
+    to the appinfo.vdf binary file
+    """
+    def func(steam_app, compat_tool_name):
+        manifest_appinfo = next(
+            section["appinfo"] for section
+            in iter_appinfo_sections(steam_dir / "appcache" / "appinfo.vdf")
+            if section["appinfo"]["appid"] == 891390
+        )
+
+        manifest_appinfo["extended"]["app_mappings"][str(steam_app.appid)] = {
+            "appid": steam_app.appid,
+            "tool": compat_tool_name
+        }
+
+        # Update the appinfo.vdf with the compat tools that have been
+        # added so far.
+        appinfo_factory(
+            appid=891390,  # Steam Play 2.0 Manifests app ID,
+            appinfo=manifest_appinfo
+        )
+
+    return func
+
+
 @pytest.fixture(scope="function", autouse=True)
 def appinfo_factory(steam_dir):
     """
@@ -364,7 +392,8 @@ def appinfo_factory(steam_dir):
             "appinfo": {
                 "appid": 891390,
                 "extended": {
-                    "compat_tools": {}
+                    "compat_tools": {},
+                    "app_mappings": {}
                 }
             }
         }

tests/test_steam.py

@@ -285,8 +285,6 @@ def test_find_legacy_tool_mapping_global(
         )
         assert proton_app.name == "Proton B"
 
-
-
     @pytest.mark.usefixtures("steam_deck", "info_logging")
     def test_find_steam_deck_profile(
             self, steam_app_factory, proton_factory, appinfo_factory,
@@ -374,6 +372,49 @@ def test_find_steam_default_proton(
             if "Using stable version of Proton" in record.message
         )
 
+    @pytest.mark.usefixtures("info_logging")
+    def test_find_steam_steamplay_manifest_app_mapping(
+            self, steam_app_factory, steam_dir, proton_factory,
+            appinfo_app_mapping_factory, steam_config_path, caplog):
+        """
+        Ensure the function returns the Proton version defined in the
+        Steam Play manifest if one is defined
+        """
+        steam_app = steam_app_factory(name="Fake game", appid=10)
+        proton_app = proton_factory(
+            name="Test Proton", appid=123450, compat_tool_name="test-proton"
+        )
+
+        appinfo_app_mapping_factory(
+            steam_app=steam_app, compat_tool_name="test-proton"
+        )
+
+        steam_config_path.write_text(
+            vdf.dumps({
+                "InstallConfigStore": {
+                    "Software": {
+                        "Valve": {
+                            "Steam": {}
+                        }
+                    }
+                }
+            })
+        )
+
+        proton_app = find_steam_compat_tool_app(
+            steam_path=steam_dir,
+            steam_apps=[steam_app, proton_app],
+            appid=10
+        )
+
+        assert proton_app.appid == 123450
+
+        assert any(
+            record for record in caplog.records
+            if "App has default compatibility tool mapping in the Steam Play"
+            in record.message
+        )
+
 
 class TestFindLibraryPaths:
     @pytest.mark.parametrize(