Intorduce ConfigSource.lsp_config to hook at updating

Author: flying-foozy

pyls/config/config.py

@@ -144,6 +144,13 @@ def plugin_settings(self, plugin, document_path=None):
 
     def update(self, settings):
         """Recursively merge the given settings into the current settings."""
+        sources = settings.get('configurationSources', DEFAULT_CONFIG_SOURCES) + ['pyls']
+        for source_name in reversed(sources):
+            source = self._config_sources.get(source_name)
+            if not source:
+                continue
+            source.lsp_config(settings)
+
         self.settings.cache_clear()
         self._settings = settings
         log.info("Updated settings to %s", self._settings)

pyls/config/source.py

@@ -25,6 +25,16 @@ def project_config(self, document_path):
         """Return project-level (i.e. workspace directory) configuration."""
         raise NotImplementedError()
 
+    def lsp_config(self, config):
+        """Check configuration at updating.
+
+        Typical usecase is updating via LSP didChangeConfiguration
+        method.
+
+        Change config directly, if any changing like normalization is
+        needed. It is nested dictionay.
+        """
+
     @staticmethod
     def read_config_from_files(files):
         config = configparser.RawConfigParser()