Ignore non-object values for initializationOptions

Fixes #65.

CHANGELOG.md

@@ -13,6 +13,7 @@
 - Update LanguageTool to 5.3 (see [LT 5.3 release notes](https://github.com/languagetool-org/languagetool/blob/v5.3/languagetool-standalone/CHANGES.md#53-2021-03-29))
 - Update LSP4J to 0.12.0
 - Add `FR_SPELLING_RULE` as a rule for unknown words ([PR #47](https://github.com/valentjn/ltex-ls/pull/47) by [Nicolas Sicard (@biozic)](https://github.com/biozic))
+- Ignore non-object values for `InitializeParams.initializationOptions` (fixes [#65](https://github.com/valentjn/ltex-ls/issues/65))
 
 ## 10.0.0 (February 12, 2021)
 

ltexls-core/src/main/java/org/bsplines/ltexls/server/LtexLanguageServer.java

@@ -7,6 +7,7 @@
 
 package org.bsplines.ltexls.server;
 
+import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import java.time.Instant;
 import java.util.ArrayList;
@@ -73,9 +74,12 @@ public CompletableFuture<InitializeResult> initialize(InitializeParams params) {
       }
     }
 
-    @Nullable JsonObject initializationOptions = (JsonObject)params.getInitializationOptions();
+    @Nullable JsonElement initializationOptionsElement =
+        (JsonElement)params.getInitializationOptions();
+
+    if ((initializationOptionsElement != null) && initializationOptionsElement.isJsonObject()) {
+      JsonObject initializationOptions = (JsonObject)initializationOptionsElement;
 
-    if (initializationOptions != null) {
       // Until it is specified in the LSP that the locale is automatically sent with
       // the initialization request, we have to do that manually.
       // See https://github.com/microsoft/language-server-protocol/issues/754.