Decimal Arithmetics

Sources/MoneyProtocol.swift

@@ -151,6 +151,41 @@ extension MoneyProtocol where FloatLiteralType == Decimal.FloatLiteralType {
     }
 }
 
+extension MoneyProtocol {
+
+	public static func +(lhs: Self, rhs: Decimal) -> Self {
+		return Self(decimal: lhs.decimal + rhs)
+	}
+
+	public static func +(lhs: Decimal, rhs: Self) -> Self {
+		return Self(decimal: lhs + rhs.decimal)
+	}
+
+	public static func -(lhs: Self, rhs: Decimal) -> Self {
+		return Self(decimal: lhs.decimal - rhs)
+	}
+
+	public static func -(lhs: Decimal, rhs: Self) -> Self {
+		return Self(decimal: lhs - rhs.decimal)
+	}
+
+	public static func *(lhs: Self, rhs: Decimal) -> Self {
+		return Self(decimal: lhs.decimal * rhs)
+	}
+
+	public static func *(lhs: Decimal, rhs: Self) -> Self {
+		return Self(decimal: lhs * rhs.decimal)
+	}
+
+	public static func /(lhs: Self, rhs: Decimal) -> Self {
+		return Self(decimal: lhs.decimal / rhs)
+	}
+
+	public static func /(lhs: Decimal, rhs: Self) -> Self {
+		return Self(decimal: lhs / rhs.decimal)
+	}
+}
+
 public extension MoneyProtocol {
 
     func distance(to other: Self) -> Self {

Tests/AdditionTests.swift

@@ -31,6 +31,14 @@ extension MoneyTestCase {
         let result = 3.5 + money + 2.5
         XCTAssertEqual(result, 16)
     }
+
+	func test__money_addition_by_decimals() {
+		money = 10
+		let a: Decimal = 3.5
+		let b: Decimal = 2.5
+		let result = a + money + b
+		XCTAssertEqual(result, 16)
+	}
 }
 
 extension MoneyTestCase {
@@ -52,4 +60,12 @@ extension MoneyTestCase {
         let result = 3.5 + gbp + 2.5
         XCTAssertEqual(result, 16)
     }
+
+	func test__iso_addition_by_decimals() {
+		gbp = 10
+		let a: Decimal = 3.5
+		let b: Decimal = 2.5
+		let result = a + gbp + b
+		XCTAssertEqual(result, 16)
+	}
 }

Tests/DivisionTests.swift

@@ -31,6 +31,14 @@ extension MoneyTestCase {
         let result = 3.5 / money / 2.5
         XCTAssertEqual(result.floatValue, 0.14, accuracy: 0.001)
     }
+
+	func test__money_division_by_decimals() {
+		money = 10
+		let a: Decimal = 3.5
+		let b: Decimal = 2.5
+		let result = a / money / b
+		XCTAssertEqual(result.floatValue, 0.14, accuracy: 0.001)
+	}
 }
 
 extension MoneyTestCase {
@@ -52,6 +60,14 @@ extension MoneyTestCase {
         let result = 3.5 / gbp / 2.5
         XCTAssertEqual(result.floatValue, 0.14, accuracy: 0.001)
     }
+
+	func test__iso_division_by_decimals() {
+		gbp = 10
+		let a: Decimal = 3.5
+		let b: Decimal = 2.5
+		let result = a / gbp / b
+		XCTAssertEqual(result.floatValue, 0.14, accuracy: 0.001)
+	}
 }
 
 

Tests/MultiplicationTests.swift

@@ -31,6 +31,14 @@ extension MoneyTestCase {
         let result = 3.5 * money * 2.5
         XCTAssertEqual(result, 87.5)
     }
+
+	func test__money_multiplation_by_decimals() {
+		money = 10
+		let a: Decimal = 3.5
+		let b: Decimal = 2.5
+		let result = a * money * b
+		XCTAssertEqual(result, 87.5)
+	}
 }
 
 extension MoneyTestCase {
@@ -52,4 +60,12 @@ extension MoneyTestCase {
         let result = 3.5 * gbp * 2.5
         XCTAssertEqual(result, 87.5)
     }
+
+	func test__iso_multiplation_by_decimals() {
+		gbp = 10
+		let a: Decimal = 3.5
+		let b: Decimal = 2.5
+		let result = a * gbp * b
+		XCTAssertEqual(result, 87.5)
+	}
 }