Simplify event stream (#36)

* Simplify event store by re-using overloads

* Move QueryableExtensions to System.Linq

* Fix naming of private field

* Implement derivable overloads with extension methods

* Rename IEventStream back to IEventStore

GitVersion.yml

@@ -1,5 +1,5 @@
 mode: ContinuousDelivery
-next-version: 0.4.1
+next-version: 0.5.0
 branches:
   master:
     tag: beta

src/RdbmsEventStore.EntityFramework.Tests/EventStoreTests/ExtraMetaTests.cs

@@ -43,7 +43,7 @@ public ExtraMetaTests(ExtraMetaEventFactoryFixture fixture, AssemblyInitializerF
         [InlineData("stream-2", 2)]
         public async Task ReturnsEventsFromCorrectStreamOnly(string streamId, long expectedCount)
         {
-            var store = _fixture.BuildEventStore(_dbContext) as IEventStream<string, ExtraMetaStringEvent, IExtraMeta>;
+            var store = _fixture.BuildEventStore(_dbContext) as IEventStore<string, ExtraMetaStringEvent, IExtraMeta>;
             var events = await store.Events(streamId);
             Assert.Equal(expectedCount, events.Count());
         }
@@ -53,7 +53,7 @@ public async Task ReturnsEventsFromCorrectStreamOnly(string streamId, long expec
         [InlineData("stream-2", 1)]
         public async Task ReturnsEventsAccordingToQuery(string streamId, long expectedCount)
         {
-            var store = _fixture.BuildEventStore(_dbContext) as IEventStream<string, ExtraMetaStringEvent, IExtraMeta>;
+            var store = _fixture.BuildEventStore(_dbContext) as IEventStore<string, ExtraMetaStringEvent, IExtraMeta>;
             var events = await store.Events(streamId, es => es.Where(e => e.ExtraMeta.StartsWith("Foo")));
             Assert.Equal(expectedCount, events.Count());
         }
@@ -63,7 +63,7 @@ public async Task ReturnsEventsAccordingToQuery(string streamId, long expectedCo
         [InlineData("stream-2", 1)]
         public async Task ReturnsEventsWithMetadata(string streamId, long expectedCount)
         {
-            var store = _fixture.BuildEventStore(_dbContext) as IEventStream<string, ExtraMetaStringEvent, IExtraMeta>;
+            var store = _fixture.BuildEventStore(_dbContext) as IEventStore<string, ExtraMetaStringEvent, IExtraMeta>;
             var events = await store.Events(streamId, es => es.Where(e => e.ExtraMeta.StartsWith("Foo")));
             Assert.All(events, @event => Assert.StartsWith("Foo", @event.ExtraMeta));
         }
@@ -73,7 +73,7 @@ public async Task ReturnsEventsWithMetadata(string streamId, long expectedCount)
         [InlineData("stream-2", 1)]
         public async Task CanQueryByExtraMetadata(string streamId, long expectedCount)
         {
-            var store = _fixture.BuildEventStore(_dbContext) as IEventStream<string, ExtraMetaStringEvent, IExtraMeta>;
+            var store = _fixture.BuildEventStore(_dbContext) as IEventStore<string, ExtraMetaStringEvent, IExtraMeta>;
             var events = await store.Events(streamId, es => es.Where(e => e.ExtraMeta.StartsWith("Foo")));
             Assert.Equal(expectedCount, events.Count());
         }

src/RdbmsEventStore.EntityFramework.Tests/EventStoreTests/QueryEventsTests.cs

@@ -32,7 +32,7 @@ public QueryEventsTests(EventStoreFixture<long, string, StringEvent, IEventMetad
         [InlineData("stream-2", 2)]
         public async Task ReturnsEventsFromCorrectStreamOnly(string streamId, long expectedCount)
         {
-            var store = _fixture.BuildEventStore(_dbContext) as IEventStream<string, StringEvent, IEventMetadata<string>>;
+            var store = _fixture.BuildEventStore(_dbContext) as IEventStore<string, StringEvent, IEventMetadata<string>>;
             var events = await store.Events(streamId);
             Assert.Equal(expectedCount, events.Count());
         }
@@ -42,23 +42,23 @@ public async Task ReturnsEventsFromCorrectStreamOnly(string streamId, long expec
         [InlineData("stream-2", 1)]
         public async Task ReturnsEventsAccordingToQuery(string streamId, long expectedCount)
         {
-            var store = _fixture.BuildEventStore(_dbContext) as IEventStream<string, StringEvent, IEventMetadata<string>>;
+            var store = _fixture.BuildEventStore(_dbContext) as IEventStore<string, StringEvent, IEventMetadata<string>>;
             var events = await store.Events(streamId, es => es.Where(e => e.Version > 1));
             Assert.Equal(expectedCount, events.Count());
         }
 
         [Fact]
         public async Task ReturnsAllEvents()
         {
-            var store = _fixture.BuildEventStore(_dbContext) as IEventStream<string, StringEvent, IEventMetadata<string>>;
+            var store = _fixture.BuildEventStore(_dbContext) as IEventStore<string, StringEvent, IEventMetadata<string>>;
             var events = await store.Events();
             Assert.Equal(5, events.Count());
         }
 
         [Fact]
         public async Task ReturnsAllEventsAccordingToQuery()
         {
-            var store = _fixture.BuildEventStore(_dbContext) as IEventStream<string, StringEvent, IEventMetadata<string>>;
+            var store = _fixture.BuildEventStore(_dbContext) as IEventStore<string, StringEvent, IEventMetadata<string>>;
             var events = await store.Events(es => es.Where(e => e.Version > 1));
             Assert.Equal(3, events.Count());
         }

src/RdbmsEventStore.EntityFramework.Tests/ExtensibilityTests/NonDefaultImplementationsTests.cs

@@ -79,7 +79,7 @@ public async Task CanReadEventsFromStoreWithNonDefaultImplementations()
             });
             await _dbContext.SaveChangesAsync();
 
-            var store = _fixture.BuildEventStore(_dbContext) as IEventStream<long, NonDefaultEvent, IEventMetadata<long>>;
+            var store = _fixture.BuildEventStore(_dbContext) as IEventStore<long, NonDefaultEvent, IEventMetadata<long>>;
 
             var events = await store.Events(1);
 

src/RdbmsEventStore.EntityFramework/EntityFrameworkEventStore.cs

@@ -7,32 +7,30 @@
 
 namespace RdbmsEventStore.EntityFramework
 {
-    public class EntityFrameworkEventStore<TId, TStreamId, TContext, TEvent, TEventMetadata, TPersistedEvent> : IEventStream<TStreamId, TEvent, TEventMetadata>
+    public class EntityFrameworkEventStore<TId, TStreamId, TContext, TEvent, TEventMetadata, TPersistedEvent> : IEventStore<TStreamId, TEvent, TEventMetadata>
         where TId : IEquatable<TId>
         where TStreamId : IEquatable<TStreamId>
         where TContext : DbContext, IEventDbContext<TPersistedEvent>
         where TEvent : class, TEventMetadata, IMutableEvent<TStreamId>, new()
         where TPersistedEvent : class, IPersistedEvent<TStreamId>, TEventMetadata, new()
         where TEventMetadata : class, IEventMetadata<TStreamId>
     {
-        private readonly TContext context;
+        private readonly TContext _context;
         private readonly IEventFactory<TStreamId, TEvent> _eventFactory;
         private readonly IWriteLock<TStreamId> _writeLock;
         private readonly IEventSerializer<TEvent, TPersistedEvent> _serializer;
 
         public EntityFrameworkEventStore(TContext context, IEventFactory<TStreamId, TEvent> eventFactory, IWriteLock<TStreamId> writeLock, IEventSerializer<TEvent, TPersistedEvent> serializer)
         {
-            this.context = context;
+            _context = context;
             _eventFactory = eventFactory;
             _writeLock = writeLock;
             _serializer = serializer;
         }
 
-        public  Task<IEnumerable<TEvent>> Events() => Events(events => events);
-
         public async Task<IEnumerable<TEvent>> Events(Func<IQueryable<TEventMetadata>, IQueryable<TEventMetadata>> query)
         {
-            var storedEvents = await context.Events
+            var storedEvents = await _context.Events
                 .AsNoTracking()
                 .Apply(query)
                 .OrderBy(e => e.Timestamp)
@@ -45,32 +43,11 @@ public async Task<IEnumerable<TEvent>> Events(Func<IQueryable<TEventMetadata>, I
             return events;
         }
 
-        public Task<IEnumerable<TEvent>> Events(TStreamId streamId) => Events(streamId, events => events);
-
-        public async Task<IEnumerable<TEvent>> Events(TStreamId streamId, Func<IQueryable<TEventMetadata>, IQueryable<TEventMetadata>> query)
-        {
-            var storedEvents = await context.Events
-                    .Where(e => e.StreamId.Equals(streamId))
-                    .AsNoTracking()
-                    .Apply(query)
-                    .OrderBy(e => e.Timestamp)
-                    .ToListAsync();
-
-            var events = storedEvents
-                .Cast<TPersistedEvent>()
-                .Select(_serializer.Deserialize);
-
-            return events;
-        }
-
-        public Task Append(TStreamId streamId, long versionBefore, object payload)
-            => Append(streamId, versionBefore, new[] { payload });
-
         public async Task Append(TStreamId streamId, long versionBefore, IEnumerable<object> payloads)
         {
             using (await _writeLock.Aquire(streamId))
             {
-                var highestVersionNumber = await context.Events
+                var highestVersionNumber = await _context.Events
                     .Where(e => e.StreamId.Equals(streamId))
                     .Select(e => e.Version)
                     .DefaultIfEmpty(0)
@@ -82,8 +59,8 @@ public async Task Append(TStreamId streamId, long versionBefore, IEnumerable<obj
                 }
 
                 var events = _eventFactory.Create(streamId, versionBefore, payloads).Select(_serializer.Serialize);
-                context.Events.AddRange(events);
-                await context.SaveChangesAsync();
+                _context.Events.AddRange(events);
+                await _context.SaveChangesAsync();
             }
         }
     }

src/RdbmsEventStore/EventStoreExtensions.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace RdbmsEventStore
+{
+    public static class EventStoreExtensions
+    {
+        public static Task<IEnumerable<TEvent>> Events<TStreamId, TEvent, TEventMetadata>(this IEventStore<TStreamId, TEvent, TEventMetadata> store)
+            where TStreamId : IEquatable<TStreamId>
+            where TEvent : class, TEventMetadata, IEvent<TStreamId>
+            where TEventMetadata : class, IEventMetadata<TStreamId>
+            => store.Events(events => events);
+
+        public static Task<IEnumerable<TEvent>> Events<TStreamId, TEvent, TEventMetadata>(this IEventStore<TStreamId, TEvent, TEventMetadata> store, TStreamId streamId)
+            where TStreamId : IEquatable<TStreamId>
+            where TEvent : class, TEventMetadata, IEvent<TStreamId>
+            where TEventMetadata : class, IEventMetadata<TStreamId>
+            => store.Events(streamId, events => events);
+
+        public static Task<IEnumerable<TEvent>> Events<TStreamId, TEvent, TEventMetadata>(this IEventStore<TStreamId, TEvent, TEventMetadata> store, TStreamId streamId, Func<IQueryable<TEventMetadata>, IQueryable<TEventMetadata>> query)
+            where TStreamId : IEquatable<TStreamId>
+            where TEvent : class, TEventMetadata, IEvent<TStreamId>
+            where TEventMetadata : class, IEventMetadata<TStreamId>
+            => store.Events(events => events.Where(e => e.StreamId.Equals(streamId)).Apply(query));
+
+        public static Task Append<TStreamId, TEvent, TEventMetadata>(this IEventStore<TStreamId, TEvent, TEventMetadata> store, TStreamId streamId, long versionBefore, object payload)
+            where TStreamId : IEquatable<TStreamId>
+            where TEvent : class, TEventMetadata, IEvent<TStreamId>
+            where TEventMetadata : class, IEventMetadata<TStreamId>
+            => store.Append(streamId, versionBefore, new[] { payload });
+    }
+}

src/RdbmsEventStore/IEventStream.cs → src/RdbmsEventStore/IEventStore.cs

@@ -5,20 +5,13 @@
 
 namespace RdbmsEventStore
 {
-    public interface IEventStream<in TStreamId, TEvent, TEventMetadata>
+    public interface IEventStore<in TStreamId, TEvent, TEventMetadata>
+        where TStreamId : IEquatable<TStreamId>
         where TEvent : IEvent<TStreamId>, TEventMetadata
         where TEventMetadata : IEventMetadata<TStreamId>
     {
-        Task<IEnumerable<TEvent>> Events();
-
         Task<IEnumerable<TEvent>> Events(Func<IQueryable<TEventMetadata>, IQueryable<TEventMetadata>> query);
 
-        Task<IEnumerable<TEvent>> Events(TStreamId streamId);
-
-        Task<IEnumerable<TEvent>> Events(TStreamId streamId, Func<IQueryable<TEventMetadata>, IQueryable<TEventMetadata>> query);
-
-        Task Append(TStreamId streamId, long versionBefore, object payload);
-
         Task Append(TStreamId streamId, long versionBefore, IEnumerable<object> payloads);
     }
 }

src/RdbmsEventStore/QueryableExtensions.cs

@@ -0,0 +1,8 @@
+// ReSharper disable once CheckNamespace
+namespace System.Linq
+{
+    public static class QueryableExtensions
+    {
+        public static IQueryable<T> Apply<T>(this IQueryable<T> source, Func<IQueryable<T>, IQueryable<T>> projection) => projection(source);
+    }
+}