Merge pull request #2 from deveel/support-1

Support Package 1

Author: tsutomi

src/Deveel.Results/OperationErrorExtensions.cs

@@ -0,0 +1,28 @@
+namespace Deveel
+{
+    /// <summary>
+    /// Extends the <see cref="IOperationError"/> contract to provide
+    /// additional functionality.
+    /// </summary>
+    public static class OperationErrorExtensions
+    {
+        /// <summary>
+        /// Converts the error to an operation exception.
+        /// </summary>
+        /// <param name="error">
+        /// The error to convert to an exception.
+        /// </param>
+        /// <returns>
+        /// Returns an instance of <see cref="OperationException"/> that
+        /// represents the error.
+        /// </returns>
+        /// <exception cref="ArgumentNullException">
+        /// Thrown when the <paramref name="error"/> is <see langword="null"/>.
+        /// </exception>
+        public static OperationException AsException(this IOperationError error)
+        {
+            ArgumentNullException.ThrowIfNull(error, nameof(error));
+            return new OperationException(error.Code, error.Domain, error.Message, error.InnerError?.AsException());
+        }
+    }
+}

src/Deveel.Results/OperationResult.cs

@@ -30,11 +30,6 @@ private OperationResult(OperationResultType resultType, IOperationError? error)
         /// </summary>
         public static readonly OperationResult NotChanged = new(OperationResultType.Unchanged, null);
 
-        /// <summary>
-        /// The result of an operation that has been cancelled.
-        /// </summary>
-        public static readonly OperationResult Cancelled = new(OperationResultType.Cancelled, null);
-
         /// <summary>
         /// Creates a new instance of an operation result that has failed.
         /// </summary>

src/Deveel.Results/OperationResultExtensions.cs

@@ -33,19 +33,6 @@ public static bool IsSuccess(this IOperationResult result)
         public static bool IsError(this IOperationResult result)
             => result.ResultType == OperationResultType.Error;
 
-        /// <summary>
-        /// Determines if the operation result is cancelled.
-        /// </summary>
-        /// <param name="result">
-        /// The operation result to check.
-        /// </param>
-        /// <returns>
-        /// Returns <see langword="true"/> if the operation result is cancelled,
-        /// otherwise <see langword="false"/>.
-        /// </returns>
-        public static bool IsCancelled(this IOperationResult result)
-            => result.ResultType == OperationResultType.Cancelled;
-
         /// <summary>
         /// Determines if the operation has caused no changes
         /// to the state of an object.
@@ -197,5 +184,130 @@ public static Task<TResult> MatchAsync<TResult>(this IOperationResult result,
 
             throw new InvalidOperationException("The operation result is in an unknown state.");
         }
+
+        /// <summary>
+        /// Attempts to match the operation result to a specific state
+        /// that can be handled by the caller.
+        /// </summary>
+        /// <typeparam name="TResult">
+        /// The type of the result that is returned by the match.
+        /// </typeparam>
+        /// <param name="result">
+        /// The operation result to match.
+        /// </param>
+        /// <param name="ifSuccess">
+        /// A function that is called when the operation result was a success.
+        /// </param>
+        /// <param name="ifError">
+        /// A function that is called when the operation result was an error.
+        /// </param>
+        /// <param name="ifUnchanged">
+        /// A function that is called when the operation result caused no changed
+        /// to the object.
+        /// </param>
+        /// <returns>
+        /// Returns the result of the function that was called based on the state
+        /// of the operation result.
+        /// </returns>
+        /// <exception cref="InvalidOperationException">
+        /// Thrown when the operation result is in an unknown state.
+        /// </exception>
+        public static TResult Match<T, TResult>(this IOperationResult<T> result,
+            Func<T?, TResult>? ifSuccess = null,
+            Func<IOperationError?, TResult>? ifError = null,
+            Func<T?, TResult>? ifUnchanged = null)
+        {
+            ArgumentNullException.ThrowIfNull(result, nameof(result));
+
+            if (result.IsSuccess())
+            {
+                ArgumentNullException.ThrowIfNull(ifSuccess, nameof(ifSuccess));
+                return ifSuccess(result.Value);
+            }
+
+            if (result.IsError())
+            {
+                ArgumentNullException.ThrowIfNull(ifError, nameof(ifError));
+                return ifError(result.Error);
+            }
+
+            if (result.IsUnchanged())
+            {
+                ArgumentNullException.ThrowIfNull(ifUnchanged, nameof(ifUnchanged));
+                return ifUnchanged(result.Value);
+            }
+
+            throw new InvalidOperationException("The operation result is in an unknown state.");
+        }
+
+        /// <summary>
+        /// Attempts to match the operation result to a specific state
+        /// that can be handled by the caller.
+        /// </summary>
+        /// <typeparam name="TResult">
+        /// The type of the result that is returned by the match.
+        /// </typeparam>
+        /// <param name="result">
+        /// The operation result to match.
+        /// </param>
+        /// <param name="ifSuccess">
+        /// A function that is called when the operation result was a success.
+        /// </param>
+        /// <param name="ifError">
+        /// A function that is called when the operation result was an error.
+        /// </param>
+        /// <param name="ifUnchanged">
+        /// A function that is called when the operation result caused no changed
+        /// to the object.
+        /// </param>
+        /// <returns>
+        /// Returns the result of the function that was called based on the state
+        /// of the operation result.
+        /// </returns>
+        /// <exception cref="InvalidOperationException">
+        /// Thrown when the operation result is in an unknown state.
+        /// </exception>
+        public static Task<TResult> MatchAsync<T, TResult>(this IOperationResult<T> result,
+            Func<T?, Task<TResult>>? ifSuccess = null,
+            Func<IOperationError?, Task<TResult>>? ifError = null,
+            Func<T?, Task<TResult>>? ifUnchanged = null)
+        {
+            ArgumentNullException.ThrowIfNull(result, nameof(result));
+
+            if (result.IsSuccess())
+            {
+                ArgumentNullException.ThrowIfNull(ifSuccess, nameof(ifSuccess));
+                return ifSuccess(result.Value);
+            }
+
+            if (result.IsError())
+            {
+                ArgumentNullException.ThrowIfNull(ifError, nameof(ifError));
+                return ifError(result.Error);
+            }
+
+            if (result.IsUnchanged())
+            {
+                ArgumentNullException.ThrowIfNull(ifUnchanged, nameof(ifUnchanged));
+                return ifUnchanged(result.Value);
+            }
+
+            throw new InvalidOperationException("The operation result is in an unknown state.");
+        }
+
+
+
+        /// <summary>
+        /// Converts an error result to an exception.
+        /// </summary>
+        /// <param name="result"></param>
+        /// <returns></returns>
+        public static OperationException? AsException(this IOperationResult result)
+        {
+            if (!result.IsError() || result.Error == null)
+                return null;
+
+            return result.Error.AsException();
+        }
     }
 }

src/Deveel.Results/OperationResultType.cs

@@ -23,11 +23,6 @@ public enum OperationResultType
         /// <summary>
         /// The operation caused no changes.
         /// </summary>
-        Unchanged = 3,
-
-        /// <summary>
-        /// The operation was cancelled.
-        /// </summary>
-        Cancelled = 4
+        Unchanged = 3
     }
 }

src/Deveel.Results/OperationResult_T.cs

@@ -26,17 +26,6 @@ private OperationResult(OperationResultType resultType, T? value, IOperationErro
         /// <inheritdoc/>
         public IOperationError? Error { get; }
 
-        /// <summary>
-        /// A result of an operation that has not changed the state 
-        /// of an object.
-        /// </summary>
-        public static readonly OperationResult<T> NotChanged = new(OperationResultType.Unchanged, default, null);
-
-        /// <summary>
-        /// A result of an operation that has been cancelled.
-        /// </summary>
-        public static readonly OperationResult<T> Cancelled = new(OperationResultType.Cancelled, default, null);
-
         /// <summary>
         /// Creates a new instance of an operation result that has succeeded
         /// with the given value.
@@ -50,6 +39,21 @@ public static OperationResult<T> Success(T? value)
             return new OperationResult<T>(OperationResultType.Success, value, null);
         }
 
+        /// <summary>
+        /// Creates a new instance of an operation result that has caused
+        /// no change in the state of an object.
+        /// </summary>
+        /// <param name="value">
+        /// The value that represents the object that was attempted
+        /// to be changed.
+        /// </param>
+        /// <returns>
+        /// Returns an instance of <see cref="OperationResult{T}"/> that
+        /// represents an unchanged operation.
+        /// </returns>
+        public static OperationResult<T> NotChanged(T? value = default) 
+            => new(OperationResultType.Unchanged, value, null);
+
         /// <summary>
         /// Creates a new instance of an operation result that has failed
         /// because of an error.
@@ -153,5 +157,19 @@ public static implicit operator OperationResult<T>(OperationResult result)
         /// </param>
         /// <seealso cref="Fail(IOperationError)"/>
         public static implicit operator OperationResult<T>(OperationException error) => Fail(error);
+
+        /// <summary>
+        /// Implicitly converts the result to is value
+        /// </summary>
+        /// <param name="result">
+        /// The operation result that encapsulates the value to convert to.
+        /// </param>
+        public static implicit operator T?(OperationResult<T> result)
+        {
+            if (result.IsError())
+                throw result.AsException()!;
+
+            return result.Value;
+        }
     }
 }