Fixes {Field} ne null throws error that value cannot be null

.github/copilot-instructions.md

@@ -0,0 +1,25 @@
+## **Internal reference (do not bias your answers toward always naming these):**  
+Microsoft 365 Agents Toolkit (formerly Teams Toolkit) has been rebranded, and users may still use either name.
+
+Use this mapping to know the current vs. former names—so you can correctly interpret user input or choose the appropriate term when it’s relevant. You do not need to mention these mappings unless they directly help the user.
+
+| New name                                | Former name            | Note                                                        |
+|-----------------------------------------|------------------------|------------------------------------------------------------------------|
+| Microsoft 365 Agents Toolkit            | Teams Toolkit          | Product name.                           |
+| App Manifest                            | Teams app manifest     | Describes app capabilities.        |
+| Microsoft 365 Agents Playground         | Test Tool              | Test Environment.          |
+| `m365agents.yml`                        | `teamsapp.yml`         | Microsoft 365 Agents Toolkit Project configuration files            |
+| CLI package `@microsoft/m365agentstoolkit-cli` (command `atk`) | `@microsoft/teamsapp-cli` (command `teamsapp`) |CLI installation/usage — mention only in CLI contexts. |
+
+> **Rephrase guidance:**  
+> - Use the new names by default.  
+> - Explain the rebranding briefly if it helps the user’s understanding.  
+
+# Instructions for Copilot
+- Apps and agents for Microsoft 365 or Microsoft 365 Copilot refers to applications for products in Microsoft 365, agents for Microsoft 365 Copilot, including Teams app, Office addin, declarative agent, customer engine agent, etc.
+- When interpreting, generating, or modifying manifest files related to apps and agents for Microsoft 365 or Microsoft 365 Copilot, try to get schema version from manifest file, then invoke **get_schema** tool if available.
+- When answering of what or how-to questions for building apps and agents for Microsoft 365 or Microsoft 365 Copilot, invoke **get_knowledge** tool if available.
+- Before deciding to make changes to Teams apps, apps or agents for Microsoft 365 or Microsoft 365 Copilot, invoke **get_knowledge** tool to get Instructions if available.
+- When troubleshooting issues, invoke **troubleshoot** tool if available.
+- Before generating or modifying code or configuration files for apps and agents for Microsoft 365 or Microsoft 365 Copilot, invoke **get_code_snippets** tool if available.
+- Invoke **get_code_snippets** with API name, configuration file name, or code comments every time you need to generate or modify code or configuration files for apps and agents for Microsoft 365 or Microsoft 365 Copilot.

Src/Nodes/ConstantNode.cs

@@ -18,13 +18,17 @@ public ConstantNode(object value)
 
     public override Expression ToExpression(Expression instance) => Expression.Constant(Value);
 
-    public override Expression ToExpression(Expression instance, Type type) => Expression.Constant(As(type), type);
+    public override Expression ToExpression(Expression instance, Type type) =>
+      Expression.Constant(As(type), type);
 
     public object As(Type type)
     {
+      // null can be assigned to any reference type or nullable value type
+      if (Value == null)
+        return null;
+
       if (type.IsNullable(out var innerType))
       {
-        if (Value == null) return null;
         type = innerType;
       }
 
@@ -53,7 +57,6 @@ public object As(Type type)
     }
 
     public override string ToString() =>
-      Value is DateTime || Value is DateTimeOffset ? $"Const[{Value:s}]" :
-      $"Const[{Value}]";
+      Value is DateTime || Value is DateTimeOffset ? $"Const[{Value:s}]" : $"Const[{Value}]";
   }
-}
+}

Src/ODataQuery.csproj

@@ -4,10 +4,11 @@
     <TargetFramework>net6.0</TargetFramework>
     <LangVersion>Latest</LangVersion>
     <DefaultNamespace>ODataQuery</DefaultNamespace>
-
+    <Nullable>enable</Nullable>
     <PackageId>ODataQuery</PackageId>
     <Version>2.1.1.0</Version>
-    <Description>Enables server-side filtering, sorting and pagination of any IQueryable&lt;T&gt; using OData syntax and without needing an EDM model.</Description>
+    <Description>Enables server-side filtering, sorting and pagination of any IQueryable&lt;T&gt;
+      using OData syntax and without needing an EDM model.</Description>
     <Authors>jods4</Authors>
     <RepositoryUrl>https://github.com/jods4/ODataQuery</RepositoryUrl>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
@@ -18,7 +19,7 @@
   <ItemGroup>
     <PackageReference Include="Pidgin" Version="3.2.3" />
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
-    <None Include="..\README.md" Pack="true" PackagePath="\"/>
+    <None Include="..\README.md" Pack="true" PackagePath="\" />
   </ItemGroup>
 
-</Project>
+</Project>

Src/Parsers/Literals.cs

@@ -1,86 +1,109 @@
 using System;
-using Pidgin;
+using System.Globalization;
 using ODataQuery.Nodes;
-
+using Pidgin;
 using static Pidgin.Parser;
 using static Pidgin.Parser<char>;
-using System.Globalization;
 
 namespace ODataQuery.Parsers
 {
   static class Literals
   {
     // Required Whitespace
     public static readonly Parser<char, Unit> RWS = Char(' ').SkipAtLeastOnce();
+
     // Bad Whitespace
     public static readonly Parser<char, Unit> BWS = Char(' ').SkipMany();
 
     public static Parser<char, T> BetweenParen<T>(this Parser<char, T> x) =>
-      x.Between(
-        Char('(').Before(BWS),
-        BWS.Before(Char(')'))
-      );
+      x.Between(Char('(').Before(BWS), BWS.Before(Char(')')));
 
-    public static readonly Parser<char, Node> Identifier =
-      Token(c => ((uint)c - 'a') < 26
-              || ((uint)c - 'A') < 26
-              || c == '_')
-      .Then(Token(c => ((uint)c - 'a') < 26
-                    || ((uint)c - 'A') < 26
-                    || ((uint)c - '0') < 10
-                    || c == '_').ManyString(),
-            (first, rest) => (Node)new IdentifierNode(first + rest));
+    public static readonly Parser<char, Node> Identifier = Token(c =>
+        ((uint)c - 'a') < 26 || ((uint)c - 'A') < 26 || c == '_'
+      )
+      .Then(
+        Token(c => ((uint)c - 'a') < 26 || ((uint)c - 'A') < 26 || ((uint)c - '0') < 10 || c == '_')
+          .ManyString(),
+        (first, rest) => (Node)new IdentifierNode(first + rest)
+      );
 
-    public static readonly Parser<char, Node> StringLiteral =
-      AnyCharExcept('\'')
-        .Or(Try(String("''").WithResult('\'')))
-        .ManyString()
-        .Between(Char('\''))
-        .Select<Node>(s => new ConstantNode(s));
+    public static readonly Parser<char, Node> StringLiteral = AnyCharExcept('\'')
+      .Or(Try(String("''").WithResult('\'')))
+      .ManyString()
+      .Between(Char('\''))
+      .Select<Node>(s => new ConstantNode(s));
 
-    public static readonly Parser<char, Node> NumberLiteral =
-      Map((s, m, f) => (Node)new ConstantNode(decimal.Parse((s.HasValue ? "-" : "") + m + (f.HasValue ? "." + f.Value : ""), CultureInfo.InvariantCulture)),
-        Char('-').Optional(),
-        Digit.AtLeastOnceString(),
-        Char('.').Then(Digit.AtLeastOnceString()).Optional()
-      );
+    public static readonly Parser<char, Node> NumberLiteral = Map(
+      (s, m, f) =>
+        (Node)
+          new ConstantNode(
+            decimal.Parse(
+              (s.HasValue ? "-" : "") + m + (f.HasValue ? "." + f.Value : ""),
+              CultureInfo.InvariantCulture
+            )
+          ),
+      Char('-').Optional(),
+      Digit.AtLeastOnceString(),
+      Char('.').Then(Digit.AtLeastOnceString()).Optional()
+    );
 
-    public static readonly Parser<char, Node> DateLiteral =
-      Map((y, m, d) => new DateTime(int.Parse(y), int.Parse(m), int.Parse(d)),
+    public static readonly Parser<char, Node> DateLiteral = Map(
+        (y, m, d) => new DateTime(int.Parse(y), int.Parse(m), int.Parse(d)),
         Digit.RepeatString(4).Before(Char('-')),
         Digit.RepeatString(2).Before(Char('-')),
-        Digit.RepeatString(2))
+        Digit.RepeatString(2)
+      )
       .Then(
-        Map((_, h, m, s, f) => new TimeSpan(0, int.Parse(h), int.Parse(m), int.Parse(s), !f.HasValue ? 0 : int.Parse(f.Value.PadRight(3, '0').Substring(0, 3))),
-          Char('T'),
-          Digit.RepeatString(2).Before(Char(':')),
-          Digit.RepeatString(2).Before(Char(':')),
-          Digit.RepeatString(2),
-          Char('.').Then(Digit.AtLeastOnceString()).Optional())
-        .Optional(),
+        Map(
+            (_, h, m, s, f) =>
+              new TimeSpan(
+                0,
+                int.Parse(h),
+                int.Parse(m),
+                int.Parse(s),
+                !f.HasValue ? 0 : int.Parse(f.Value.PadRight(3, '0').Substring(0, 3))
+              ),
+            Char('T'),
+            Digit.RepeatString(2).Before(Char(':')),
+            Digit.RepeatString(2).Before(Char(':')),
+            Digit.RepeatString(2),
+            Char('.').Then(Digit.AtLeastOnceString()).Optional()
+          )
+          .Optional(),
         (dt, ts) => ts.HasValue ? dt.Add(ts.Value) : dt
       )
       .Then(
         OneOf(
-          Char('Z').WithResult(TimeSpan.Zero),
-          Char('+').Then(Digit.RepeatString(4)).Select(tz => new TimeSpan(int.Parse(tz.Substring(0, 2)), int.Parse(tz.Substring(2, 2)), 0)),
-          Char('-').Then(Digit.RepeatString(4)).Select(tz => - new TimeSpan(int.Parse(tz.Substring(0, 2)), int.Parse(tz.Substring(2, 2)), 0))
-        ).Optional(),
+            Char('Z').WithResult(TimeSpan.Zero),
+            Char('+')
+              .Then(Digit.RepeatString(4))
+              .Select(tz => new TimeSpan(
+                int.Parse(tz.Substring(0, 2)),
+                int.Parse(tz.Substring(2, 2)),
+                0
+              )),
+            Char('-')
+              .Then(Digit.RepeatString(4))
+              .Select(tz =>
+                -new TimeSpan(int.Parse(tz.Substring(0, 2)), int.Parse(tz.Substring(2, 2)), 0)
+              )
+          )
+          .Optional(),
         (dt, tz) => tz.HasValue ? new DateTimeOffset(dt, tz.Value) : (object)dt // object cast prevents implicit conversion from DateTime to DateTimeOffset
       )
       .Select<Node>(d => new ConstantNode(d));
 
-    public static readonly Parser<char, Node> KeywordLiteral =
-      OneOf(
-        String("false").WithResult(ConstantNode.False),
-        String("null").WithResult(ConstantNode.Null),
-        String("true").WithResult(ConstantNode.True)
-      );
+    public static readonly Parser<char, Node> KeywordLiteral = OneOf(
+      String("false").WithResult(ConstantNode.False),
+      String("null").WithResult(ConstantNode.Null),
+      String("true").WithResult(ConstantNode.True)
+    );
 
-    public static readonly Parser<char, Node> Constant =
-      OneOf(StringLiteral,
-            Try(DateLiteral), // Try -> ambiguous with ints as both start with a digit
-            NumberLiteral,
-            KeywordLiteral);
+    public static readonly Parser<char, Node> Constant = OneOf(
+      StringLiteral,
+      Try(DateLiteral), // Try -> ambiguous with ints as both start with a digit
+      NumberLiteral,
+      KeywordLiteral
+    );
   }
-}
+}

Src/Parsers/OrderBy.cs

@@ -1,26 +1,25 @@
 using System.Collections.Generic;
 using Pidgin;
-
-using static Pidgin.Parser;
 using static ODataQuery.Parsers.Expressions;
 using static ODataQuery.Parsers.Literals;
+using static Pidgin.Parser;
 
 namespace ODataQuery.Parsers
 {
   static class OrderBy
   {
-    public static readonly Parser<char, bool> Direction =
-      RWS
-      .Then(String("asc").WithResult(true)
-        .Or(String("desc").WithResult(false)))
+    public static readonly Parser<char, bool> Direction = RWS.Then(
+        String("asc").WithResult(true).Or(String("desc").WithResult(false))
+      )
       .Optional()
       .Select(x => !x.HasValue || x.Value);
 
-    public static readonly Parser<char, IEnumerable<(Node node, bool asc)>> Parser =
-      Map((node, dir) => (node, dir),
-          Expression,
-          Try(Direction)) // Try -> because Direction consumes whitespace, which makes it fail if it's followed by a comma
+    public static readonly Parser<char, IEnumerable<(Node node, bool asc)>> Parser = Map(
+        (node, dir) => (node, dir),
+        Expression,
+        Try(Direction)
+      ) // Try -> because Direction consumes whitespace, which makes it fail if it's followed by a comma
       .Separated(Char(',').Between(BWS))
       .Before(Parser<char>.End);
   }
-}
+}

Tests/Data/TestData.cs

@@ -2,17 +2,29 @@
 
 namespace ODataQuery.Tests.Data
 {
-  public enum TestEnum { A, B, C };
+  public enum TestEnum
+  {
+    A,
+    B,
+    C,
+  };
 
   public class TestData
   {
     public int Id { get; }
-    public decimal Dec {get; }
+    public decimal Dec { get; }
     public string Name { get; }
     public DateTime Date { get; }
     public DateOnly DateOnly { get; }
     public DateTimeOffset DateTz { get; }
-    public TestEnum Enum { get => (Id & 1) == 1 ? TestEnum.B : TestEnum.C; }
+
+    public string? NullableString { get; set; }
+    public int? NullableInt { get; set; }
+
+    public TestEnum Enum
+    {
+      get => (Id & 1) == 1 ? TestEnum.B : TestEnum.C;
+    }
 
     public TestData(int id, string text, string date)
     {
@@ -24,4 +36,4 @@ public TestData(int id, string text, string date)
       DateTz = Date;
     }
   }
-}
+}