gently trap graphql parse errors in the LS and LSP

I introduced these accidentally and they have caused a lot of issues!

Author: acao

.changeset/wise-birds-notice.md

@@ -0,0 +1,6 @@
+---
+'graphql-language-service': patch
+'graphql-language-service-server': patch
+---
+
+Trap all graphql parsing exceptions from (relatively) newly added logic. This should clear up bugs that have been plauging users for two years now, sorry!

packages/graphql-language-service-server/src/MessageProcessor.ts

@@ -690,12 +690,13 @@ export class MessageProcessor {
     }
 
     const inlineFragments: string[] = [];
-
-    visit(parse(query), {
-      FragmentDefinition: (node: FragmentDefinitionNode) => {
-        inlineFragments.push(node.name.value);
-      },
-    });
+    try {
+      visit(parse(query), {
+        FragmentDefinition: (node: FragmentDefinitionNode) => {
+          inlineFragments.push(node.name.value);
+        },
+      });
+    } catch {}
 
     const formatted = result
       ? result.definitions.map(res => {

packages/graphql-language-service/src/interface/getAutocompleteSuggestions.ts

@@ -79,11 +79,15 @@ export const SuggestionCommand = {
 const collectFragmentDefs = (op: string | undefined) => {
   const externalFragments: FragmentDefinitionNode[] = [];
   if (op) {
-    visit(parse(op), {
-      FragmentDefinition(def) {
-        externalFragments.push(def);
-      },
-    });
+    try {
+      visit(parse(op), {
+        FragmentDefinition(def) {
+          externalFragments.push(def);
+        },
+      });
+    } catch {
+      return [];
+    }
   }
   return externalFragments;
 };