fix: get source text exeptions

src/OmniSharp.Roslyn.CSharp/Services/InlayHints/InlayHintService.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Composition;
 using System.Diagnostics.CodeAnalysis;
@@ -56,8 +57,17 @@ public async Task<InlayHintResponse> Handle(InlayHintRequest request)
             return InlayHintResponse.None;
         }
 
-        var sourceText = await document.GetTextAsync();
-        var mappedSpan = sourceText.GetSpanFromRange(request.Location.Range);
+        SourceText sourceText;
+        TextSpan mappedSpan;
+        try
+        {
+            sourceText = await document.GetTextAsync();
+            mappedSpan = sourceText.GetSpanFromRange(request.Location.Range);
+        }
+        catch (ArgumentOutOfRangeException)
+        {
+            return InlayHintResponse.None;
+        }
 
         var inlayHintsOptions = _omniSharpOptions.CurrentValue.RoslynExtensionsOptions.InlayHintsOptions;
         var options = new OmniSharpInlineHintsOptions

src/OmniSharp.Roslyn.CSharp/Services/Signatures/SignatureHelpService.cs

@@ -1,10 +1,12 @@
+using System;
 using System.Collections.Generic;
 using System.Composition;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Text;
 using OmniSharp.Extensions;
 using OmniSharp.Mef;
 using OmniSharp.Models;
@@ -103,8 +105,17 @@ throughExpression is LiteralExpressionSyntax ||
 
         private async Task<InvocationContext> GetInvocation(Document document, Request request)
         {
-            var sourceText = await document.GetTextAsync();
-            var position = sourceText.GetTextPosition(request);
+            SourceText sourceText;
+            int position;
+            try
+            {
+                sourceText = await document.GetTextAsync();
+                position = sourceText.GetTextPosition(request);
+            }
+            catch (ArgumentOutOfRangeException)
+            {
+                return null;
+            }
             var tree = await document.GetSyntaxTreeAsync();
             var root = await tree.GetRootAsync();
             var node = root.FindToken(position).Parent;