chore: import upstream snapshot with attribution

dotnet/samples/03-workflows/Declarative/InvokeFunctionTool/MenuPlugin.cs

@@ -0,0 +1,85 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.ComponentModel;
+
+namespace Demo.Workflows.Declarative.InvokeFunctionTool;
+
+#pragma warning disable CA1822 // Mark members as static
+
+/// <summary>
+/// Plugin providing menu-related functions that can be invoked directly by the workflow
+/// using the InvokeFunctionTool action.
+/// </summary>
+public sealed class MenuPlugin
+{
+    [Description("Provides a list items on the menu.")]
+    public MenuItem[] GetMenu()
+    {
+        return s_menuItems;
+    }
+
+    [Description("Provides a list of specials from the menu.")]
+    public MenuItem[] GetSpecials()
+    {
+        return [.. s_menuItems.Where(i => i.IsSpecial)];
+    }
+
+    [Description("Provides the price of the requested menu item.")]
+    public float? GetItemPrice(
+        [Description("The name of the menu item.")]
+        string name)
+    {
+        return s_menuItems.FirstOrDefault(i => i.Name.Equals(name, StringComparison.OrdinalIgnoreCase))?.Price;
+    }
+
+    private static readonly MenuItem[] s_menuItems =
+        [
+            new()
+            {
+                Category = "Soup",
+                Name = "Clam Chowder",
+                Price = 4.95f,
+                IsSpecial = true,
+            },
+            new()
+            {
+                Category = "Soup",
+                Name = "Tomato Soup",
+                Price = 4.95f,
+                IsSpecial = false,
+            },
+            new()
+            {
+                Category = "Salad",
+                Name = "Cobb Salad",
+                Price = 9.99f,
+            },
+            new()
+            {
+                Category = "Salad",
+                Name = "House Salad",
+                Price = 4.95f,
+            },
+            new()
+            {
+                Category = "Drink",
+                Name = "Chai Tea",
+                Price = 2.95f,
+                IsSpecial = true,
+            },
+            new()
+            {
+                Category = "Drink",
+                Name = "Soda",
+                Price = 1.95f,
+            },
+        ];
+
+    public sealed class MenuItem
+    {
+        public string Category { get; init; } = string.Empty;
+        public string Name { get; init; } = string.Empty;
+        public float Price { get; init; }
+        public bool IsSpecial { get; init; }
+    }
+}