Add pin delegate for clock and clockoffset

- this enables clock offsetting capabilities

Author: Scott Williams

DateTimeAbstractions.v3.ncrunchsolution

@@ -0,0 +1,6 @@
+<SolutionConfiguration>
+  <Settings>
+    <AllowParallelTestExecution>True</AllowParallelTestExecution>
+    <SolutionConfigured>True</SolutionConfigured>
+  </Settings>
+</SolutionConfiguration>

src/Tocsoft.DateTimeAbstractions/Clock.cs

@@ -44,13 +44,23 @@ public static IDisposable Pin()
         /// <summary>
         /// Pins the specified date/time retuned to the current time until the disposable is disposed.
         /// </summary>
-        /// <param name="date">The date and time to the clocks time to.</param>
+        /// <param name="date">The date and time to the clock.</param>
         /// <returns>The disposer that manages the lifetime of the scoped pinned value.</returns>
         public static IDisposable Pin(DateTime date)
         {
             return Pin(new StaticDateTimeProvider(date));
         }
 
+        /// <summary>
+        /// Pins the clock to call the function every time it needs access to the current time until the disposable is disposed.
+        /// </summary>
+        /// <param name="dateFunc">The function that returnes date and time to the clocks.</param>
+        /// <returns>The disposer that manages the lifetime of the scoped pinned value.</returns>
+        public static IDisposable Pin(Func<DateTime> dateFunc)
+        {
+            return Pin(new DelegateDateTimeProvider(dateFunc));
+        }
+
         internal static IDisposable Pin(DateTimeProvider provider)
         {
             ImmutableStack<DateTimeProvider> stack = clockStack.Value ?? ImmutableStack.Create<DateTimeProvider>();
@@ -82,12 +92,12 @@ public void Dispose()
         /// <summary>
         /// Gets the current local DateTime unless pinned then it will returned the pinned time as a local time.
         /// </summary>
-        public static DateTime Now => CurrentProvider.Now();
+        public static DateTime Now => CurrentProvider.UtcNow().ToLocalTime();
 
         /// <summary>
         /// Gets the current the Date portion of the current local DateTime unless pinned then it will returned the date portion of the pinned time.
         /// </summary>
-        public static DateTime Today => CurrentProvider.Now().Date;
+        public static DateTime Today => Now.Date;
 
         /// <summary>
         /// Gets the current UTC DateTime unless pinned then it will returned the pinned time as a UTC time.

src/Tocsoft.DateTimeAbstractions/ClockOffset.cs

@@ -51,6 +51,16 @@ public static IDisposable Pin(DateTimeOffset date)
             return Pin(new StaticDateTimeOffsetProvider(date));
         }
 
+        /// <summary>
+        /// Pins the clock to call the function every time it needs access to the current time until the disposable is disposed.
+        /// </summary>
+        /// <param name="dateFunc">The function that returnes date and time to the clocks.</param>
+        /// <returns>The disposer that manages the lifetime of the scoped pinned value.</returns>
+        public static IDisposable Pin(Func<DateTimeOffset> dateFunc)
+        {
+            return Pin(new DelegateDateTimeOffsetProvider(dateFunc));
+        }
+
         internal static IDisposable Pin(DateTimeOffsetProvider provider)
         {
             ImmutableStack<DateTimeOffsetProvider> stack = clockStack.Value ?? ImmutableStack.Create<DateTimeOffsetProvider>();
@@ -82,7 +92,7 @@ public void Dispose()
         /// <summary>
         /// Gets the current local DateTimeOffset unless pinned then it will returned the pinned time as a local time.
         /// </summary>
-        public static DateTimeOffset Now => CurrentProvider.Now();
+        public static DateTimeOffset Now => CurrentProvider.UtcNow().ToLocalTime();
 
         /// <summary>
         /// Gets the current UTC DateTimeOffset unless pinned then it will returned the pinned time as a UTC time.

src/Tocsoft.DateTimeAbstractions/Providers/CurrentDateTimeOffsetProvider.cs

@@ -7,11 +7,6 @@ namespace Tocsoft.DateTimeAbstractions.Providers
 {
     internal class CurrentDateTimeOffsetProvider : DateTimeOffsetProvider
     {
-        public override DateTimeOffset Now()
-        {
-            return DateTimeOffset.Now;
-        }
-
         public override DateTimeOffset UtcNow()
         {
             return DateTimeOffset.UtcNow;

src/Tocsoft.DateTimeAbstractions/Providers/CurrentDateTimeProvider.cs

@@ -7,11 +7,6 @@ namespace Tocsoft.DateTimeAbstractions.Providers
 {
     internal class CurrentDateTimeProvider : DateTimeProvider
     {
-        public override DateTime Now()
-        {
-            return DateTime.Now;
-        }
-
         public override DateTime UtcNow()
         {
             return DateTime.UtcNow;

src/Tocsoft.DateTimeAbstractions/Providers/DateTimeOffsetProvider.cs

@@ -7,8 +7,6 @@ namespace Tocsoft.DateTimeAbstractions.Providers
 {
     internal abstract class DateTimeOffsetProvider
     {
-        public abstract DateTimeOffset Now();
-
         public abstract DateTimeOffset UtcNow();
     }
 }

src/Tocsoft.DateTimeAbstractions/Providers/DateTimeProvider.cs

@@ -7,8 +7,6 @@ namespace Tocsoft.DateTimeAbstractions.Providers
 {
     internal abstract class DateTimeProvider
     {
-        public abstract DateTime Now();
-
         public abstract DateTime UtcNow();
     }
 }

src/Tocsoft.DateTimeAbstractions/Providers/DelegateDateTimeOffsetProvider.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Tocsoft and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+
+namespace Tocsoft.DateTimeAbstractions.Providers
+{
+    internal class DelegateDateTimeOffsetProvider : DateTimeOffsetProvider
+    {
+        private readonly Func<DateTimeOffset> dateFunc;
+
+        public DelegateDateTimeOffsetProvider(Func<DateTimeOffset> dateFunc)
+        {
+            this.dateFunc = dateFunc;
+        }
+
+        public override DateTimeOffset UtcNow()
+        {
+            return this.dateFunc().ToUniversalTime();
+        }
+    }
+}

src/Tocsoft.DateTimeAbstractions/Providers/DelegateDateTimeProvider.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Tocsoft and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+
+namespace Tocsoft.DateTimeAbstractions.Providers
+{
+    internal class DelegateDateTimeProvider : DateTimeProvider
+    {
+        private readonly Func<DateTime> datefunc;
+
+        public DelegateDateTimeProvider(Func<DateTime> datefunc)
+        {
+            this.datefunc = datefunc;
+        }
+
+        public override DateTime UtcNow()
+        {
+            return this.datefunc().ToUniversalTime();
+        }
+    }
+}

src/Tocsoft.DateTimeAbstractions/Providers/StaticDateTimeOffsetProvider.cs

@@ -7,20 +7,13 @@ namespace Tocsoft.DateTimeAbstractions.Providers
 {
     internal class StaticDateTimeOffsetProvider : DateTimeOffsetProvider
     {
-        private readonly DateTimeOffset date;
         private readonly DateTimeOffset utcdate;
 
         public StaticDateTimeOffsetProvider(DateTimeOffset date)
         {
-            this.date = date.ToLocalTime();
             this.utcdate = date.ToUniversalTime();
         }
 
-        public override DateTimeOffset Now()
-        {
-            return this.date;
-        }
-
         public override DateTimeOffset UtcNow()
         {
             return this.utcdate;