Add .clampedZeroToHundred (#12)

Co-authored-by: Sindre Sorhus <[email protected]>

Sources/Percentage/Percentage.swift

@@ -62,6 +62,30 @@ public struct Percentage: Hashable, Codable {
 	*/
 	public var fraction: Double { rawValue / 100 }
 
+	/**
+	Clamp the percentage to a value between 0% and 100%.
+
+	```
+	110%.clampedZeroToHundred
+	//=> 100%
+
+	-1%.clampedZeroToHundred
+	//=> 0%
+
+	60%.clampedZeroToHundred
+	//=> 60%
+	```
+	*/
+	public var clampedZeroToHundred: Self {
+		if rawValue > 100 {
+			return 100%
+		} else if rawValue < 0 {
+			return 0%
+		} else {
+			return self
+		}
+	}
+
 	/**
 	Create a `Percentage` from a `BinaryFloatingPoint`, for example, `Double` or `CGFloat`.
 

Tests/PercentageTests/PercentageTests.swift

@@ -32,6 +32,12 @@ final class PercentageTests: XCTestCase {
 		XCTAssertTrue(30% > 25%)
 	}
 
+	func testClampedZeroToHundred() {
+		XCTAssertEqual(101%.clampedZeroToHundred, 100%)
+		XCTAssertEqual((-1%).clampedZeroToHundred, 0%)
+		XCTAssertEqual(40%.clampedZeroToHundred, 40%)
+	}
+
 	func testPercentageOf() {
 		XCTAssertEqual(50%.of(200), 100)
 		XCTAssertEqual(50%.of(201), 100)

readme.md

@@ -56,6 +56,9 @@ Percentage(fraction: 0.5)
 10%.rawValue
 //=> 10
 
+110%.clampedZeroToHundred
+//=> 100%
+
 print("\(1%)")
 //=> "1%"