Add subscription support to source generator (#1729)

docs/4-code-generator/05-samples-sg-subscriptions.md

@@ -0,0 +1,13 @@
+## Subscriptions
+
+Code generator will generate object definition and extensions methods for adding subscription 
+types to the schema. Generator will generate a subscriber for each `IAsyncEnumerable<T>` method
+of a class with `[ObjectType]` attribute. You can use provided extension method to add the 
+subscription type, subscribers and resolver to the schema.
+
+
+### Tanka.GraphQL.Samples.SG.Subscription
+
+```csharp
+#include::xref://samples:GraphQL.Samples.SG.Subscription/Program.cs
+```

docs/4-code-generator/nav.md

@@ -1,4 +1,5 @@
 - [Installation & basics](xref://01-samples-sg-basic.md)
 - [Arguments](xref://02-samples-sg-arguments.md)
 - [Namespace](xref://03-samples-sg-namespace.md)
-- [Dependency injection](xref://04-samples-sg-services.md)
+- [Dependency injection](xref://04-samples-sg-services.md)
+- [Subscriptions](xref://05-samples-sg-subscriptions.md)

samples/GraphQL.Samples.SG.InputType/Program.cs

@@ -1,4 +1,3 @@
-using System.Collections.Concurrent;
 using Microsoft.AspNetCore.Mvc;
 
 using Tanka.GraphQL;

samples/GraphQL.Samples.SG.Subscription/GraphQL.Samples.SG.Subscription.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\GraphQL.Language\GraphQL.Language.csproj" />
+    <ProjectReference Include="..\..\src\GraphQL.Server\GraphQL.Server.csproj" />
+    <ProjectReference Include="..\..\src\GraphQL\GraphQL.csproj" />
+  </ItemGroup>
+
+	<ItemGroup>
+		<ProjectReference Include="..\..\src\GraphQL.Server.SourceGenerators\GraphQL.Server.SourceGenerators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+	</ItemGroup>
+
+</Project>

samples/GraphQL.Samples.SG.Subscription/Program.cs

@@ -0,0 +1,55 @@
+using System.Runtime.CompilerServices;
+
+using Tanka.GraphQL.Server;
+
+WebApplicationBuilder builder = WebApplication.CreateBuilder(args);
+
+builder.AddTankaGraphQL()
+    .AddHttp()
+    .AddWebSockets()
+    .AddSchemaOptions("Default", options =>
+    {
+        // This extension point is used by the generator to add
+        // type controllers
+        options.AddGeneratedTypes(types =>
+        {
+            // Add generated controllers
+            types
+                .AddQueryController()
+                .AddSubscriptionController();
+        });
+    });
+
+WebApplication app = builder.Build();
+app.UseWebSockets();
+
+app.MapTankaGraphQL("/graphql", "Default");
+app.MapGraphiQL("/graphql/ui");
+app.Run();
+
+[ObjectType]
+public static class Subscription
+{
+    /// <summary>
+    ///     This is subscription field producing random integers of count between from and to 
+    /// </summary>
+    /// <returns></returns>
+    public static async IAsyncEnumerable<int> Random(int from, int to, int count, [EnumeratorCancellation] CancellationToken cancellationToken)
+    {
+        var r = new Random();
+
+        for (var i = 0; i < count; i++)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            yield return r.Next(from, to);
+            await Task.Delay(500, cancellationToken);
+        }
+    }
+}
+
+[ObjectType]
+public static class Query
+{
+    // this is required as the graphiql will error without a query field
+    public static string Hello() => "Hello World!";
+}

samples/GraphQL.Samples.SG.Subscription/Properties/launchSettings.json

@@ -0,0 +1,14 @@
+{
+  "profiles": {
+    "GraphQL.Samples.SG.Subscription": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "launchUrl": "https://localhost:7239/graphql/ui",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      },
+      "applicationUrl": "https://localhost:7239",
+      "dotnetRunMessages": true
+    }
+  }
+}

samples/GraphQL.Samples.SG.Subscription/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

samples/GraphQL.Samples.SG.Subscription/appsettings.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}

src/GraphQL.Server.SourceGenerators/Internal/EquatableArray.cs

@@ -0,0 +1,115 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+
+namespace Tanka.GraphQL.Server.SourceGenerators.Internal;
+
+public static class EquatableArrayExtensions
+{
+    public static EquatableArray<T> ToEquatableArray<T>(this IEnumerable<T> array)
+        where T : IEquatable<T>
+    {
+        return new(array.ToArray());
+
+    }
+}
+
+/// <summary>
+/// Origin https://github.com/andrewlock/NetEscapades.EnumGenerators
+/// An immutable, equatable array. This is equivalent to <see cref="Array"/> but with value equality support.
+/// </summary>
+/// <typeparam name="T">The type of values in the array.</typeparam>
+public readonly struct EquatableArray<T> : IEquatable<EquatableArray<T>>, IEnumerable<T>
+    where T : IEquatable<T>
+{
+    /// <summary>
+    /// The underlying <typeparamref name="T"/> array.
+    /// </summary>
+    private readonly T[]? _array;
+
+    /// <summary>
+    /// Creates a new <see cref="EquatableArray{T}"/> instance.
+    /// </summary>
+    /// <param name="array">The input <see cref="ImmutableArray{T}"/> to wrap.</param>
+    public EquatableArray(T[] array)
+    {
+        _array = array;
+    }
+
+    /// <sinheritdoc/>
+    public bool Equals(EquatableArray<T> array)
+    {
+        return AsSpan().SequenceEqual(array.AsSpan());
+    }
+
+    /// <sinheritdoc/>
+    public override bool Equals(object? obj)
+    {
+        return obj is EquatableArray<T> array && Equals(this, array);
+    }
+
+    /// <sinheritdoc/>
+    public override int GetHashCode()
+    {
+        if (_array is not T[] array)
+        {
+            return 0;
+        }
+
+        HashCode hashCode = default;
+
+        foreach (T item in array)
+        {
+            hashCode.Add(item);
+        }
+
+        return hashCode.ToHashCode();
+    }
+
+    /// <summary>
+    /// Returns a <see cref="ReadOnlySpan{T}"/> wrapping the current items.
+    /// </summary>
+    /// <returns>A <see cref="ReadOnlySpan{T}"/> wrapping the current items.</returns>
+    public ReadOnlySpan<T> AsSpan()
+    {
+        return _array.AsSpan();
+    }
+
+    /// <sinheritdoc/>
+    IEnumerator<T> IEnumerable<T>.GetEnumerator()
+    {
+        return ((IEnumerable<T>)(_array ?? Array.Empty<T>())).GetEnumerator();
+    }    
+
+    /// <sinheritdoc/>
+    IEnumerator IEnumerable.GetEnumerator()
+    {
+        return ((IEnumerable<T>)(_array ?? Array.Empty<T>())).GetEnumerator();
+    }
+
+    public int Count => _array?.Length ?? 0;
+
+    /// <summary>
+    /// Checks whether two <see cref="EquatableArray{T}"/> values are the same.
+    /// </summary>
+    /// <param name="left">The first <see cref="EquatableArray{T}"/> value.</param>
+    /// <param name="right">The second <see cref="EquatableArray{T}"/> value.</param>
+    /// <returns>Whether <paramref name="left"/> and <paramref name="right"/> are equal.</returns>
+    public static bool operator ==(EquatableArray<T> left, EquatableArray<T> right)
+    {
+        return left.Equals(right);
+    }
+
+    /// <summary>
+    /// Checks whether two <see cref="EquatableArray{T}"/> values are not the same.
+    /// </summary>
+    /// <param name="left">The first <see cref="EquatableArray{T}"/> value.</param>
+    /// <param name="right">The second <see cref="EquatableArray{T}"/> value.</param>
+    /// <returns>Whether <paramref name="left"/> and <paramref name="right"/> are not equal.</returns>
+    public static bool operator !=(EquatableArray<T> left, EquatableArray<T> right)
+    {
+        return !left.Equals(right);
+    }
+}