Added support forDate position between 2 dates range (positionInRange)

Sources/SwiftDate/Date/Date+Compare.swift

@@ -70,6 +70,16 @@ public extension Date {
 		return inDefaultRegion().isAfterDate(refDate.inDefaultRegion(), orEqual: orEqual, granularity: granularity)
 	}
 
+	/// Returns a value between 0.0 and 1.0 or nil, that is the position of current date between 2 other dates.
+	///
+	/// - Parameters:
+	///   - startDate: range upper bound date
+	///   - endDate: range lower bound date
+	/// - Returns: `nil` if current date is not between `startDate` and `endDate`. Otherwise returns position between `startDate` and `endDate`.
+	func positionInRange(date startDate: Date, and endDate: Date) -> Double? {
+		return inDefaultRegion().positionInRange(date: startDate.inDefaultRegion(), and: endDate.inDefaultRegion())
+	}
+
 	/// Return true if receiver date is contained in the range specified by two dates.
 	///
 	/// - Parameters:
@@ -79,7 +89,7 @@ public extension Date {
 	///   - granularity: smallest unit that must, along with all larger units, be greater for the given dates.
 	/// - Returns: Boolean
 	func isInRange(date startDate: Date, and endDate: Date, orEqual: Bool = false, granularity: Calendar.Component = .nanosecond) -> Bool {
-        return self.inDefaultRegion().isInRange(date: startDate.inDefaultRegion(), and: endDate.inDefaultRegion(), orEqual: orEqual, granularity: granularity)
+        return inDefaultRegion().isInRange(date: startDate.inDefaultRegion(), and: endDate.inDefaultRegion(), orEqual: orEqual, granularity: granularity)
 	}
 
 	/// Compares equality of two given dates based on their components down to a given unit

Sources/SwiftDate/DateInRegion/DateInRegion+Compare.swift

@@ -280,6 +280,24 @@ public extension DateInRegion {
 		return (compare(toDate: date, granularity: granularity) == .orderedSame)
 	}
 
+	/// Returns a value between 0.0 and 1.0 or nil, that is the position of current date between 2 other dates.
+	///
+	/// - Parameters:
+	///   - startDate: range upper bound date
+	///   - endDate: range lower bound date
+	/// - Returns: `nil` if current date is not between `startDate` and `endDate`. Otherwise returns position between `startDate` and `endDate`.
+	func positionInRange(date startDate: DateInRegion, and endDate: DateInRegion) -> Double? {
+		let diffCurrentDateAndStartDate = self - startDate
+		guard diffCurrentDateAndStartDate >= 0 else {
+			return nil
+		}
+		let diffEndDateAndStartDate = endDate - startDate
+		guard diffEndDateAndStartDate > 0, diffCurrentDateAndStartDate <= diffEndDateAndStartDate else {
+			return nil
+		}
+		return diffCurrentDateAndStartDate / diffEndDateAndStartDate
+	}
+
 	/// Return `true` if receiver data is contained in the range specified by two dates.
 	///
 	/// - Parameters:

Tests/SwiftDateTests/TestDate.swift

@@ -6,30 +6,51 @@
 //  Copyright © 2019 SwiftDate. All rights reserved.
 //
 
+import SwiftDate
 import XCTest
 
 class TestDate: XCTestCase {
 
-    override func setUp() {
-        // Put setup code here. This method is called before the invocation of each test method in the class.
-    }
+	override func setUp() {
+		// Put setup code here. This method is called before the invocation of each test method in the class.
+	}
 
-    override func tearDown() {
-        // Put teardown code here. This method is called after the invocation of each test method in the class.
-    }
+	override func tearDown() {
+		// Put teardown code here. This method is called after the invocation of each test method in the class.
+	}
 
-    func testDifferencesBetweenDates() {
-        let date = Date()
-        let date2 = "2019-01-05".toDate()!.date
-        let result = date.differences(in: [.hour, .day, .month], from: date2)
-        print(result)
-    }
+	func testDifferencesBetweenDates() {
+		let date = Date()
+		let date2 = "2019-01-05".toDate()!.date
+		let result = date.differences(in: [.hour, .day, .month], from: date2)
+		print(result)
+	}
 
-    func testDifferenceBetweenDates() {
-        let date = Date()
-        let date2 = "2019-01-05".toDate()!.date
-        let result = date.difference(in: .day, from: date2)
-        print(result!)
-    }
+	func testDifferenceBetweenDates() {
+		let date = Date()
+		let date2 = "2019-01-05".toDate()!.date
+		let result = date.difference(in: .day, from: date2)
+		print(result!)
+	}
 
+	func testPositionInRange() {
+		let regionRome = Region(calendar: Calendars.gregorian, zone: Zones.europeRome, locale: Locales.italian)
+		let regionLondon = Region(calendar: Calendars.gregorian, zone: Zones.europeLondon, locale: Locales.english)
+		let dateFormat = "yyyy-MM-dd HH:mm:ss"
+
+		let lowerBound = "2018-05-31 23:00:00".toDate(dateFormat, region: regionRome)!.date
+		let upperBound = "2018-06-01 01:00:00".toDate(dateFormat, region: regionRome)!.date
+
+		let testDate1 = "2018-06-01 00:30:00".toDate(dateFormat, region: regionRome)!.date
+		XCTAssertEqual( testDate1.positionInRange(date: lowerBound, and: upperBound), 0.75)
+
+		let testDate2 = "2018-05-31 22:30:00".toDate(dateFormat, region: regionLondon)!.date
+		XCTAssertEqual( testDate2.positionInRange(date: lowerBound, and: upperBound), 0.25)
+
+		let testDate3 = "2018-05-31 21:00:00".toDate(dateFormat, region: regionLondon)!.date
+		XCTAssertNil( testDate3.positionInRange(date: lowerBound, and: upperBound))
+
+		let testDate4 = "2018-06-01 03:00:00".toDate(dateFormat, region: regionLondon)!.date
+		XCTAssertNil( testDate4.positionInRange(date: lowerBound, and: upperBound))
+	}
 }

Tests/SwiftDateTests/TestDateInRegion+Compare.swift

@@ -230,6 +230,27 @@ class TestDateInRegion_Compare: XCTestCase {
 		XCTAssert( date2.isAfterDate(date1, granularity: .year) == false, "Failed to isAfterDate() - .year == false")
 	}
 
+	func testDateInRegion_positionInRange() {
+		let regionRome = Region(calendar: Calendars.gregorian, zone: Zones.europeRome, locale: Locales.italian)
+		let regionLondon = Region(calendar: Calendars.gregorian, zone: Zones.europeLondon, locale: Locales.english)
+		let dateFormat = "yyyy-MM-dd HH:mm:ss"
+
+		let lowerBound = DateInRegion("2018-05-31 23:00:00", format: dateFormat, region: regionRome)!
+		let upperBound = DateInRegion("2018-06-01 01:00:00", format: dateFormat, region: regionRome)!
+
+		let testDate1 = DateInRegion("2018-06-01 00:30:00", format: dateFormat, region: regionRome)!
+		XCTAssertEqual( testDate1.positionInRange(date: lowerBound, and: upperBound), 0.75)
+
+		let testDate2 = DateInRegion("2018-05-31 22:30:00", format: dateFormat, region: regionLondon)!
+		XCTAssertEqual( testDate2.positionInRange(date: lowerBound, and: upperBound), 0.25)
+
+		let testDate3 = DateInRegion("2018-05-31 21:00:00", format: dateFormat, region: regionLondon)!
+		XCTAssertNil( testDate3.positionInRange(date: lowerBound, and: upperBound))
+
+		let testDate4 = DateInRegion("2018-06-01 03:00:00", format: dateFormat, region: regionLondon)!
+		XCTAssertNil( testDate4.positionInRange(date: lowerBound, and: upperBound))
+	}
+
 	func testDateInRegion_isInRange() {
 		let regionRome = Region(calendar: Calendars.gregorian, zone: Zones.europeRome, locale: Locales.italian)
 		let regionLondon = Region(calendar: Calendars.gregorian, zone: Zones.europeLondon, locale: Locales.english)