Support new library folder config format

The new Steam beta stores additional data for each library folder
instead of just storing the library path as the field value.

Fixes #105

CHANGELOG.md

@@ -8,7 +8,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Fixed
  - Custom Proton installations now use Steam Runtime installations when applicable
  - Fix crash caused by older Steam app installations using a different app manifest structure
- - Fix crash caused by the change to lowercase field names in multiple VDF files
+ - Fix crash caused by change to lowercase field names in multiple VDF files
+ - Fix crash caused by change in the Steam library folder configuration file
 
 ## [1.5.1] - 2021-05-10
 ### Fixed

src/protontricks/steam.py

@@ -612,10 +612,20 @@ def parse_library_folders(data):
         """
         vdf_data = lower_dict(vdf.loads(data))
         # Library folders have integer field names in ascending order
-        library_folders = [
-            Path(value) for key, value in vdf_data["libraryfolders"].items()
+        library_entries = [
+            value for key, value in vdf_data["libraryfolders"].items()
             if key.isdigit()
         ]
+        library_folders = []
+
+        for value in library_entries:
+            if isinstance(value, dict):
+                # Library data is stored in a dict in newer Steam releases
+                library_folders.append(Path(value["path"]))
+            else:
+                # Older releases just store the library path as a string
+                # and nothing else
+                library_folders.append(Path(value))
 
         logger.info(
             "Found %d Steam library folders", len(library_folders)

tests/conftest.py

@@ -533,7 +533,7 @@ def steam_library_factory(steam_dir, steam_libraryfolders_path, tmp_path):
     """
     Factory function to add fake Steam library folders
     """
-    def func(name):
+    def func(name, new_struct=False):
         library_dir = Path(str(tmp_path)) / "mnt" / name
         library_dir.mkdir(parents=True)
 
@@ -545,9 +545,18 @@ def func(name):
         # Each new library adds a new entry into the config file with the
         # field name that starts from 1 and increases with each new library
         # folder.
+        # Newer Steam releases stores the library entry in a dict, while
+        # older releases just store the full path as the field value
         library_id = len(libraryfolders_config["LibraryFolders"].keys()) - 1
-        libraryfolders_config["LibraryFolders"][str(library_id)] = \
-            str(library_dir)
+        if new_struct:
+            libraryfolders_config["LibraryFolders"][str(library_id)] = {
+                "path": str(library_dir),
+                "label": "",
+                "mounted": "1"
+            }
+        else:
+            libraryfolders_config["LibraryFolders"][str(library_id)] = \
+                str(library_dir)
 
         steam_libraryfolders_path.write_text(vdf.dumps(libraryfolders_config))
 

tests/test_steam.py

@@ -9,7 +9,8 @@
 from protontricks.steam import (SteamApp, find_appid_proton_prefix,
                                 find_steam_path, find_steam_proton_app,
                                 get_custom_proton_installations,
-                                get_custom_windows_shortcuts, get_steam_apps)
+                                get_custom_windows_shortcuts, get_steam_apps,
+                                get_steam_lib_paths)
 
 
 class TestSteamApp:
@@ -158,6 +159,36 @@ def test_find_steam_specific_app_proton(
         assert proton_app.name == "Proton 6.66"
 
 
+class TestFindLibraryPaths:
+    @pytest.mark.parametrize(
+        "new_struct", [False, True], ids=["old struct", "new struct"]
+    )
+    def test_get_steam_lib_paths(
+            self, steam_dir, steam_library_factory, new_struct):
+        """
+        Find the Steam library folders generated with either the old or new
+        structure.
+        Older Steam releases only use a field value containing the path
+        to the library, while newer releases store a dict with additional
+        information besides the library path.
+        """
+        library_a = steam_library_factory(
+            "TestLibrary_A", new_struct=new_struct
+        )
+        library_b = steam_library_factory(
+            "TestLibrary_B", new_struct=new_struct
+        )
+
+        lib_paths = get_steam_lib_paths(steam_dir)
+
+        assert len(lib_paths) == 3
+        assert str(lib_paths[0]) == str(steam_dir)
+        assert str(lib_paths[1]) == str(library_a)
+        assert str(lib_paths[2]) == str(library_b)
+
+
+
+
 class TestFindAppidProtonPrefix:
     def test_find_appid_proton_prefix_steamapps_case(
             self, steam_app_factory, steam_dir, default_proton,