throw better exception for null id

Author: SimonCropp

src/Directory.Build.props

@@ -2,7 +2,7 @@
 <Project>
   <PropertyGroup>
     <NoWarn>CS1591;NU5104;CS1573</NoWarn>
-    <Version>21.3.0</Version>
+    <Version>21.3.1</Version>
     <AssemblyVersion>1.0.0</AssemblyVersion>
     <PackageTags>EntityFrameworkCore, EntityFramework, GraphQL</PackageTags>
     <ImplicitUsings>true</ImplicitUsings>

src/GraphQL.EntityFramework/Where/ArgumentReader.cs

@@ -23,22 +23,24 @@ string ArgumentToExpression(object argument)
             };
         }
 
-        if (context.Arguments == null)
+        var arguments = context.Arguments;
+        if (arguments == null)
         {
             result = null;
             return false;
         }
 
-        var containsIds = context.Arguments.TryGetValue("ids", out var ids);
-        var containsId = context.Arguments.TryGetValue("id", out var id);
+        var containsIds = arguments.TryGetValue("ids", out var ids);
+        var containsId = arguments.TryGetValue("id", out var id);
 
         if (!containsIds && !containsId)
         {
             result = null;
             return false;
         }
 
-        if (ids.Source == ArgumentSource.FieldDefault && id.Source == ArgumentSource.FieldDefault)
+        if (ids.Source == ArgumentSource.FieldDefault &&
+            id.Source == ArgumentSource.FieldDefault)
         {
             result = null;
             return false;
@@ -48,7 +50,13 @@ string ArgumentToExpression(object argument)
 
         if (id.Source != ArgumentSource.FieldDefault)
         {
-            expressions.Add(ArgumentToExpression(id.Value!));
+            var idValue = id.Value;
+            if (idValue == null)
+            {
+                throw new("Null 'id' is not supported.");
+            }
+
+            expressions.Add(ArgumentToExpression(idValue));
         }
 
         if (ids.Source != ArgumentSource.FieldDefault)

src/Tests/IntegrationTests/IntegrationTests.Explicit_Null.verified.txt

@@ -1,4 +1,7 @@
 {
-  target: Error trying to resolve field 'parentEntity'.,
+  target: {
+    Type: Exception,
+    Message: Null 'id' is not supported.
+  },
   sql: []
 }

src/Tests/IntegrationTests/IntegrationTests.cs

@@ -1943,7 +1943,13 @@ static async Task RunQuery(
         }
         catch (ExecutionError executionError)
         {
-            await Verify(executionError.Message, sourceFile: sourceFile);
+            await Verify(executionError.Message, sourceFile: sourceFile)
+                .IgnoreStackTrace();
+        }
+        catch (Exception exception)
+        {
+            await Verify(exception, sourceFile: sourceFile)
+                .IgnoreStackTrace();
         }
     }
 

src/Tests/IntegrationTests/QueryExecutor.cs

@@ -26,6 +26,7 @@ public static async Task<string> ExecuteQuery<TDbContext>(
         {
             Schema = schema,
             Query = query,
+            ThrowOnUnhandledException = true,
             UserContext = new UserContextSingleDb<TDbContext>(data),
             Variables = inputs,
         };