Add in-memory repository implementations for easier testing

Author: kzu

TableStorage.sln

@@ -38,6 +38,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TableStorage.Newtonsoft.Sou
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TableStorage.CodeAnalysis", "src\TableStorage.CodeAnalysis\TableStorage.CodeAnalysis.csproj", "{BC1CD1F2-5E6B-43B1-8672-E70F784F90C0}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TableStorage.Memory", "src\TableStorage.Memory\TableStorage.Memory.csproj", "{4ABD67F9-D620-4D24-8B62-B2ACD6309B4E}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -92,6 +94,10 @@ Global
 		{BC1CD1F2-5E6B-43B1-8672-E70F784F90C0}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{BC1CD1F2-5E6B-43B1-8672-E70F784F90C0}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{BC1CD1F2-5E6B-43B1-8672-E70F784F90C0}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4ABD67F9-D620-4D24-8B62-B2ACD6309B4E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4ABD67F9-D620-4D24-8B62-B2ACD6309B4E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4ABD67F9-D620-4D24-8B62-B2ACD6309B4E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4ABD67F9-D620-4D24-8B62-B2ACD6309B4E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

src/TableStorage.Memory/ConstantReducer.cs

@@ -0,0 +1,36 @@
+using System.Linq.Expressions;
+using System.Reflection;
+
+class ConstantReducer : ExpressionVisitor
+{
+    protected override Expression VisitMember(MemberExpression node)
+    {
+        // If the expression is a constant or can be reduced to a constant, evaluate it
+        if (node.Expression is ConstantExpression constantExpr)
+        {
+            object? container = constantExpr.Value;
+            object? value = null;
+
+            if (node.Member is FieldInfo field)
+                value = field.GetValue(container);
+            else if (node.Member is PropertyInfo prop)
+                value = prop.GetValue(container);
+
+            return Expression.Constant(value, node.Type);
+        }
+
+        // Try to evaluate more complex expressions
+        try
+        {
+            var lambda = Expression.Lambda(node);
+            var compiled = lambda.Compile();
+            var value = compiled.DynamicInvoke();
+            return Expression.Constant(value, node.Type);
+        }
+        catch
+        {
+            // If evaluation fails, fallback to default behavior
+            return base.VisitMember(node);
+        }
+    }
+}

src/TableStorage.Memory/MemoryPartition.cs

@@ -0,0 +1,69 @@
+//<auto-generated/>
+#nullable enable
+using System;
+using System.Collections.Concurrent;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Reflection;
+using Azure.Data.Tables;
+
+namespace Devlooped;
+
+/// <summary>
+/// Factory methods to create <see cref="ITablePartition{T}"/> instances 
+/// that store entities using individual columns for entity properties.
+/// </summary>
+public static partial class MemoryPartition
+{
+    /// <summary>
+    /// Default table name to use when a value is not not provided 
+    /// (or overriden via <see cref="TableAttribute"/>), which is <c>Entities</c>.
+    /// </summary>
+    public const string DefaultTableName = "Entities";
+
+    /// <summary>
+    /// Creates an <see cref="ITablePartition{ITableEntity}"/>.
+    /// </summary>
+    /// <param name="tableName">Table name to use.</param>
+    /// <param name="partitionKey">Fixed partition key to scope entity persistence.</param>
+    /// <returns>The new <see cref="ITablePartition{TEntity}"/>.</returns>
+    public static MemoryPartition<TableEntity> Create(string tableName, string partitionKey)
+        => new MemoryPartition<TableEntity>(tableName, partitionKey, x => x.RowKey);
+
+    /// <summary>
+    /// Creates an <see cref="ITablePartition{T}"/> for the given entity type 
+    /// <typeparamref name="T"/>, using <see cref="DefaultTableName"/> as the table name and the 
+    /// <typeparamref name="T"/> <c>Name</c> as the partition key.
+    /// </summary>
+    /// <typeparam name="T">The type of entity that the repository will manage.</typeparam>
+    /// <param name="tableName">Table name to use.</param>
+    /// <param name="rowKey">Function to retrieve the row key for a given entity.</param>
+    /// <returns>The new <see cref="ITablePartition{T}"/>.</returns>
+    public static MemoryPartition<T> Create<T>(
+        string tableName, 
+        Expression<Func<T, string>> rowKey) where T : class
+        => Create<T>(DefaultTableName, default, rowKey);
+
+    /// <summary>
+    /// Creates an <see cref="ITablePartition{T}"/> for the given entity type 
+    /// <typeparamref name="T"/>.
+    /// </summary>
+    /// <typeparam name="T">The type of entity that the repository will manage.</typeparam>
+    /// <param name="tableName">Optional table name to use. If not provided, <see cref="DefaultTableName"/> 
+    /// will be used, unless a <see cref="TableAttribute"/> on the type overrides it.</param>
+    /// <param name="partitionKey">Optional fixed partition key to scope entity persistence. 
+    /// If not provided, the <typeparamref name="T"/> <c>Name</c> will be used.</param>
+    /// <param name="rowKey">Optional function to retrieve the row key for a given entity. 
+    /// If not provided, the class will need a property annotated with <see cref="RowKeyAttribute"/>.</param>
+    /// <returns>The new <see cref="ITablePartition{T}"/>.</returns>
+    public static MemoryPartition<T> Create<T>(
+        string? tableName = default,
+        string? partitionKey = null,
+        Expression<Func<T, string>>? rowKey = null) where T : class
+    {
+        partitionKey ??= TablePartition.GetDefaultPartitionKey<T>();
+        rowKey ??= RowKeyAttribute.CreateAccessor<T>();
+
+        return new MemoryPartition<T>(tableName ?? TablePartition.GetDefaultTableName<T>(), partitionKey, rowKey);
+    }
+}

src/TableStorage.Memory/MemoryPartition`1.cs

@@ -0,0 +1,108 @@
+//<auto-generated/>
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Threading;
+using System.Threading.Tasks;
+using Azure.Data.Tables;
+using Mono.Linq.Expressions;
+
+namespace Devlooped;
+
+/// <inheritdoc />
+public partial class MemoryPartition<T> : ITablePartition<T>, IDocumentPartition<T> where T : class
+{
+    readonly MemoryRepository<T> repository;
+
+    /// <summary>
+    /// Initializes the repository with the given storage account and optional table name.
+    /// </summary>
+    /// <param name="storageAccount">The <see cref="CloudStorageAccount"/> to use to connect to the table.</param>
+    public MemoryPartition()
+        : this(TablePartition.GetDefaultTableName<T>(),
+              TablePartition.GetDefaultPartitionKey<T>(), 
+              RowKeyAttribute.CreateAccessor<T>())
+    { }
+
+    /// <summary>
+    /// Initializes the repository with the given storage account and optional table name.
+    /// </summary>
+    /// <param name="tableName">The table that backs this table partition.</param>
+    public MemoryPartition(string tableName)
+        : this(tableName ?? TablePartition.GetDefaultTableName<T>(),
+              TablePartition.GetDefaultPartitionKey<T>(),
+              RowKeyAttribute.CreateAccessor<T>())
+    { }
+
+    /// <summary>
+    /// Initializes the repository with the given storage account and optional table name.
+    /// </summary>
+    /// <param name="tableName">The table that backs this table partition.</param>
+    /// <param name="partitionKey">The fixed partition key that backs this table partition.</param>
+    public MemoryPartition(string tableName, string partitionKey)
+        : this(tableName ?? TablePartition.GetDefaultTableName<T>(), 
+              partitionKey, 
+              RowKeyAttribute.CreateAccessor<T>())
+    { }
+
+    /// <summary>
+    /// Initializes the repository with the given storage account and optional table name.
+    /// </summary>
+    /// <param name="tableName">The table that backs this table partition.</param>
+    /// <param name="partitionKey">The fixed partition key that backs this table partition.</param>
+    /// <param name="rowKey">A function to determine the row key for an entity of type <typeparamref name="T"/> within the partition.</param>
+    public MemoryPartition(string tableName, string partitionKey, Expression<Func<T, string>> rowKey)
+    {
+        partitionKey ??= TablePartition.GetDefaultPartitionKey<T>();
+        PartitionKey = partitionKey;
+
+        repository = new MemoryRepository<T>(tableName, _ => partitionKey,
+            rowKey ?? RowKeyAttribute.CreateAccessor<T>());
+    }
+
+    /// <inheritdoc />
+    public string TableName => repository.TableName;
+
+    /// <inheritdoc />
+    public string PartitionKey { get; }
+
+    /// <inheritdoc />
+    public IQueryable<T> CreateQuery() => repository.CreateQuery(PartitionKey);
+
+    /// <inheritdoc />
+    public Task<bool> DeleteAsync(T entity, CancellationToken cancellation = default)
+    {
+        if (entity is TableEntity te && !PartitionKey.Equals(te.PartitionKey, StringComparison.Ordinal))
+            throw new ArgumentException("Entity does not belong to the partition.");
+
+        return repository.DeleteAsync(entity, cancellation);
+    }
+
+    /// <inheritdoc />
+    public Task<bool> DeleteAsync(string rowKey, CancellationToken cancellation = default)
+        => repository.DeleteAsync(PartitionKey, rowKey, cancellation);
+    
+    /// <inheritdoc />
+    public IAsyncEnumerable<T> EnumerateAsync(CancellationToken cancellation = default) 
+        => repository.EnumerateAsync(PartitionKey, cancellation);
+
+    /// <inheritdoc />
+    public IAsyncEnumerable<T> EnumerateAsync(Expression<Func<IDocumentEntity, bool>> predicate, CancellationToken cancellation = default)
+        => repository.EnumerateAsync(predicate.AndAlso(x => x.PartitionKey == PartitionKey), cancellation);
+
+    /// <inheritdoc />
+    public Task<T?> GetAsync(string rowKey, CancellationToken cancellation = default)
+        => repository.GetAsync(PartitionKey, rowKey, cancellation);
+
+    /// <inheritdoc />
+    public Task<T> PutAsync(T entity, CancellationToken cancellation = default)
+    {
+        if (entity is TableEntity te && !PartitionKey.Equals(te.PartitionKey, StringComparison.Ordinal))
+            throw new ArgumentException("Entity does not belong to the partition.");
+
+        return repository.PutAsync(entity, cancellation);
+    }
+}

src/TableStorage.Memory/MemoryRepository.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Linq.Expressions;
+using Azure.Data.Tables;
+
+namespace Devlooped;
+
+/// <summary>
+/// Factory methods to create in-memory <see cref="ITableRepository{T}"/> and 
+/// <see cref="IDocumentRepository{T}"/> instances (since <see cref="MemoryRepository{T}"/> 
+/// implements both.
+/// </summary>
+public static class MemoryRepository
+{
+    /// <summary>
+    /// Creates an <see cref="ITableRepository{TableEntity}"/> repository.
+    /// </summary>
+    /// <param name="tableName">Table name to use.</param>
+    /// <returns>The new <see cref="ITableRepository{ITableEntity}"/>.</returns>
+    public static MemoryRepository<TableEntity> Create(string tableName)
+        => new(tableName, x => x.PartitionKey, x => x.RowKey);
+
+    /// <summary>
+    /// Creates an <see cref="ITableRepository{TableEntity}"/> repository.
+    /// </summary>
+    /// <returns>The new <see cref="ITableRepository{ITableEntity}"/>.</returns>
+    public static MemoryRepository<TableEntity> Create()
+        => new("Entities", x => x.PartitionKey, x => x.RowKey);
+
+    /// <summary>
+    /// Creates an <see cref="ITableRepository{T}"/> for the given entity type 
+    /// <typeparamref name="T"/>, using the <typeparamref name="T"/> <c>Name</c> as 
+    /// the table name.
+    /// </summary>
+    /// <typeparam name="T">The type of entity that the repository will manage.</typeparam>
+    /// <param name="partitionKey">Function to retrieve the partition key for a given entity.</param>
+    /// <param name="rowKey">Function to retrieve the row key for a given entity.</param>
+    /// <returns>The new <see cref="ITableRepository{T}"/>.</returns>
+    public static MemoryRepository<T> Create<T>(
+        Expression<Func<T, string>> partitionKey,
+        Expression<Func<T, string>> rowKey) where T : class
+        => Create<T>(typeof(T).Name, partitionKey, rowKey);
+
+    /// <summary>
+    /// Creates an <see cref="ITableRepository{T}"/> for the given entity type 
+    /// <typeparamref name="T"/>.
+    /// </summary>
+    /// <typeparam name="T">The type of entity that the repository will manage.</typeparam>
+    /// <param name="tableName">Optional table name to use. If not provided, the <typeparamref name="T"/> 
+    /// <param name="partitionKey">Optional function to retrieve the partition key for a given entity. 
+    /// If not provided, the class will need a property annotated with <see cref="PartitionKeyAttribute"/>.</param>
+    /// <param name="rowKey">Optional function to retrieve the row key for a given entity. 
+    /// If not provided, the class will need a property annotated with <see cref="RowKeyAttribute"/>.</param>
+    /// <returns>The new <see cref="ITableRepository{T}"/>.</returns>
+    public static MemoryRepository<T> Create<T>(
+        string? tableName = default,
+        Expression<Func<T, string>>? partitionKey = null,
+        Expression<Func<T, string>>? rowKey = null) where T : class
+    {
+        partitionKey ??= PartitionKeyAttribute.CreateAccessor<T>();
+        rowKey ??= RowKeyAttribute.CreateAccessor<T>();
+
+        return new MemoryRepository<T>(tableName ?? TableRepository.GetDefaultTableName<T>(), partitionKey, rowKey);
+    }
+}