Fix order of config initialization

Author: krassowski

packages/jupyterlab-lsp/src/connection_manager.ts

@@ -162,16 +162,28 @@ export class DocumentConnectionManager {
   }
 
   /**
-   * Currently only supports the settings that the language servers
-   * accept using onDidChangeConfiguration messages, under the
-   * "serverSettings" keyword in the setting registry. New keywords can
-   * be added and extra functionality implemented here when needed.
+   * Handles the settings that do not require an existing connection
+   * with a language server (or can influence to which server the
+   * connection will be created, e.g. `priority`).
+   *
+   * This function should be called **before** initialization of servers.
+   */
+  public updateConfiguration(allServerSettings: TLanguageServerConfigurations) {
+    this.language_server_manager.setConfiguration(allServerSettings);
+  }
+
+  /**
+   * Handles the settings that the language servers accept using
+   * `onDidChangeConfiguration` messages, which should be passed under
+   * the "serverSettings" keyword in the setting registry.
+   * Other configuration options are handled by `updateConfiguration` instead.
+   *
+   * This function should be called **after** initialization of servers.
    */
   public updateServerConfigurations(
     allServerSettings: TLanguageServerConfigurations
   ) {
     let language_server_id: TServerKeys;
-    this.language_server_manager.setConfiguration(allServerSettings);
 
     for (language_server_id in allServerSettings) {
       if (!allServerSettings.hasOwnProperty(language_server_id)) {

packages/jupyterlab-lsp/src/index.ts

@@ -179,8 +179,11 @@ export class LSPExtension implements ILSPExtension {
       .then(settings => {
         // Store the initial server settings, to be sent asynchronously
         // when the servers are initialized.
-        this.connection_manager.initial_configurations = (settings.composite
-          .language_servers || {}) as TLanguageServerConfigurations;
+        const initial_configuration = (settings.composite.language_servers ||
+          {}) as TLanguageServerConfigurations;
+        this.connection_manager.initial_configurations = initial_configuration;
+        // update the server-independent part of configuration immediately
+        this.connection_manager.updateConfiguration(initial_configuration);
 
         settings.changed.connect(() => {
           this.updateOptions(settings);
@@ -223,6 +226,10 @@ export class LSPExtension implements ILSPExtension {
 
     const languageServerSettings = (options.language_servers ||
       {}) as TLanguageServerConfigurations;
+
+    this.connection_manager.initial_configurations = languageServerSettings;
+    // TODO: if priorities changed reset connections
+    this.connection_manager.updateConfiguration(languageServerSettings);
     this.connection_manager.updateServerConfigurations(languageServerSettings);
   }
 }