Introduce the storage_path

plugin/core/sessions.py

@@ -26,6 +26,7 @@
 from .views import COMPLETION_KINDS
 from .views import did_change_configuration
 from .views import extract_variables
+from .views import get_storage_path
 from .views import SYMBOL_KINDS
 from .workspace import is_subpath_of
 from abc import ABCMeta
@@ -362,6 +363,7 @@ def configuration(cls) -> Tuple[sublime.Settings, str]:
 
         These are just the values from window.extract_variables(). Additionally,
 
+        $storage_path The path to the package storage (see AbstractPlugin.storage_path)
         $cache_path   sublime.cache_path()
         $temp_dir     tempfile.gettempdir()
         $home         os.path.expanduser('~')
@@ -386,6 +388,31 @@ def additional_variables(cls) -> Optional[Dict[str, str]]:
         """
         return None
 
+    @classmethod
+    def storage_path(cls) -> str:
+        """
+        The storage path. Use this as your base directory to install server files. Its path is '$DATA/Package Storage'.
+        You should have an additional subdirectory preferrably the same name as your plugin. For instance:
+
+        ```python
+        from LSP.plugin import AbstractPlugin
+        import os
+
+
+        class MyPlugin(AbstractPlugin):
+
+            @classmethod
+            def name(cls) -> str:
+                return "my-plugin"
+
+            @classmethod
+            def basedir(cls) -> str:
+                # Do everything relative to this directory
+                return os.path.joim(cls.storage_path(), cls.name())
+        ```
+        """
+        return get_storage_path()
+
     @classmethod
     def needs_update_or_installation(cls) -> bool:
         """

plugin/core/views.py

@@ -108,8 +108,17 @@ def get_line(window: Optional[sublime.Window], file_name: str, row: int) -> str:
         return linecache.getline(file_name, row + 1).strip()
 
 
+def get_storage_path() -> str:
+    """
+    The "Package Storage" is a way to store server data without influencing the behavior of Sublime Text's "catalog".
+    Its path is '$DATA/Package Storage'.
+    """
+    return os.path.abspath(os.path.join(sublime.cache_path(), "..", "Package Storage"))
+
+
 def extract_variables(window: sublime.Window) -> Dict[str, str]:
     variables = window.extract_variables()
+    variables["storage_path"] = get_storage_path()
     variables["cache_path"] = sublime.cache_path()
     variables["temp_dir"] = tempfile.gettempdir()
     variables["home"] = os.path.expanduser('~')