expanding nice to bolster upper and lower values using current Calendar, updated tests to match

Author: heckj

Sources/SwiftVizScale/DateScale.swift

@@ -116,10 +116,8 @@ public struct DateScale<OutputType: BinaryFloatingPoint>: ReversibleScale, Custo
         }
         precondition(min < max)
         if nice {
-            let magnitude = DateMagnitude.magnitudeOfDateRange(min, max)
-            if let bottom = min.round(magnitude: magnitude, calendar: Calendar.current) {
-                return domain(lower: bottom, higher: max)
-            }
+            let (newMin, newMax) = Date.niceExpandDomain(min: min, max: max, calendar: Calendar.current)
+            return domain(lower: newMin, higher: newMax)
         }
         return domain(lower: min, higher: max)
     }

Sources/SwiftVizScale/NiceValue.swift

@@ -432,53 +432,53 @@ public extension Date {
             }
             return niceFraction
         case .minutes:
-            let stepFractionInMinutes = step / DateMagnitude.minutesThreshold.lowerBound
+            let stepFractionInMinutes = step / DateMagnitude.minutes.seconds
             if stepFractionInMinutes <= 1 {
-                niceFraction = 1 * DateMagnitude.minutesThreshold.lowerBound
+                niceFraction = 1 * DateMagnitude.minutes.seconds
             } else if stepFractionInMinutes <= 2 {
-                niceFraction = 2 * DateMagnitude.minutesThreshold.lowerBound
+                niceFraction = 2 * DateMagnitude.minutes.seconds
             } else if stepFractionInMinutes <= 5 {
-                niceFraction = 5 * DateMagnitude.minutesThreshold.lowerBound
+                niceFraction = 5 * DateMagnitude.minutes.seconds
             } else if stepFractionInMinutes <= 10 {
-                niceFraction = 10 * DateMagnitude.minutesThreshold.lowerBound
+                niceFraction = 10 * DateMagnitude.minutes.seconds
             } else {
-                niceFraction = 30 * DateMagnitude.minutesThreshold.lowerBound
+                niceFraction = 30 * DateMagnitude.minutes.seconds
             }
             return niceFraction
         case .hours:
-            let stepFractionInHours = step / DateMagnitude.hoursThreshold.lowerBound
+            let stepFractionInHours = step / DateMagnitude.hours.seconds
             if stepFractionInHours <= 1 {
-                niceFraction = 1 * DateMagnitude.hoursThreshold.lowerBound
+                niceFraction = 1 * DateMagnitude.hours.seconds
             } else if stepFractionInHours <= 2 {
-                niceFraction = 2 * DateMagnitude.hoursThreshold.lowerBound
+                niceFraction = 2 * DateMagnitude.hours.seconds
             } else if stepFractionInHours <= 6 {
-                niceFraction = 6 * DateMagnitude.hoursThreshold.lowerBound
+                niceFraction = 6 * DateMagnitude.hours.seconds
             } else {
-                niceFraction = 12 * DateMagnitude.hoursThreshold.lowerBound
+                niceFraction = 12 * DateMagnitude.hours.seconds
             }
             return niceFraction
         case .days:
-            let stepFractionInDays = step / DateMagnitude.daysThreshold.lowerBound
+            let stepFractionInDays = step / DateMagnitude.days.seconds
             if stepFractionInDays <= 1 {
-                niceFraction = 1 * DateMagnitude.daysThreshold.lowerBound
+                niceFraction = 1 * DateMagnitude.days.seconds
             } else if stepFractionInDays <= 2 {
-                niceFraction = 2 * DateMagnitude.daysThreshold.lowerBound
+                niceFraction = 2 * DateMagnitude.days.seconds
             } else {
-                niceFraction = 7 * DateMagnitude.daysThreshold.lowerBound
+                niceFraction = 7 * DateMagnitude.days.seconds
             }
             return niceFraction
         case .months:
-            let stepFractionInMonths = step / DateMagnitude.monthsThreshold.lowerBound
+            let stepFractionInMonths = step / DateMagnitude.months.seconds
             if stepFractionInMonths <= 1 {
-                niceFraction = 1 * DateMagnitude.monthsThreshold.lowerBound
+                niceFraction = 1 * DateMagnitude.months.seconds
             } else if stepFractionInMonths <= 2 {
-                niceFraction = 2 * DateMagnitude.monthsThreshold.lowerBound
+                niceFraction = 2 * DateMagnitude.months.seconds
             } else {
-                niceFraction = 6 * DateMagnitude.monthsThreshold.lowerBound
+                niceFraction = 6 * DateMagnitude.months.seconds
             }
             return niceFraction
         case .years:
-            let stepFractionInYears = step / DateMagnitude.yearsThreshold.lowerBound
+            let stepFractionInYears = step / DateMagnitude.years.seconds
             let yearsMagnitude = floor(log10(stepFractionInYears))
             let yearsFraction = stepFractionInYears / pow(10, yearsMagnitude)
             if yearsFraction <= 1 {
@@ -494,6 +494,16 @@ public extension Date {
         }
     }
 
+    static func niceExpandDomain(min: Self, max: Self, calendar: Calendar) -> (Self, Self) {
+        let magnitude = DateMagnitude.magnitudeOfDateRange(min, max)
+        if let niceMin = min.round(magnitude: magnitude, calendar: calendar),
+           let niceMax = max.roundUp(magnitude: magnitude, calendar: calendar)
+        {
+            return (niceMin, niceMax)
+        }
+        return (min, max)
+    }
+
     static func niceMinStepMax(min: Self, max: Self, ofSize size: Int, calendar: Calendar) -> (Self, Double, Self) {
         precondition(size > 1)
         let magnitude = DateMagnitude.magnitudeOfDateRange(min, max)

Tests/SwiftVizScaleTests/DateNiceValueTests.swift

@@ -479,4 +479,34 @@ final class DateNiceValueTests: XCTestCase {
         XCTAssertTrue(resultDates.first! <= dateMin)
         XCTAssertTrue(resultDates.last! >= dateMax)
     }
+
+    func testNiceExpandDomain_days_23() throws {
+        let (formatter, now) = formatterAndNow()
+
+        let dateMin = now
+        let dateMax = now + 23.1 * DateMagnitude.days.seconds
+        // before
+        XCTAssertEqual(formatter.string(from: dateMin), "2022-08-08T22:43:09.011Z")
+        XCTAssertEqual(formatter.string(from: dateMax), "2022-09-01T01:07:09.011Z")
+
+        // after
+        let (updatedMin, updatedMax) = Date.niceExpandDomain(min: dateMin, max: dateMax, calendar: testCal)
+        XCTAssertEqual(formatter.string(from: updatedMin), "2022-08-08T00:00:00.000Z")
+        XCTAssertEqual(formatter.string(from: updatedMax), "2022-09-02T00:00:00.000Z")
+    }
+
+    func testNiceExpandDomain_hours_11() throws {
+        let (formatter, now) = formatterAndNow()
+
+        let dateMin = now
+        let dateMax = now + 11 * DateMagnitude.hours.seconds
+        // before
+        XCTAssertEqual(formatter.string(from: dateMin), "2022-08-08T22:43:09.011Z")
+        XCTAssertEqual(formatter.string(from: dateMax), "2022-08-09T09:43:09.011Z")
+
+        // after
+        let (updatedMin, updatedMax) = Date.niceExpandDomain(min: dateMin, max: dateMax, calendar: testCal)
+        XCTAssertEqual(formatter.string(from: updatedMin), "2022-08-08T22:00:00.000Z")
+        XCTAssertEqual(formatter.string(from: updatedMax), "2022-08-09T10:00:00.000Z")
+    }
 }

Tests/SwiftVizScaleTests/DateScaleTests.swift

@@ -33,9 +33,13 @@ final class DateScaleTests: XCTestCase {
         XCTAssertEqual(updated.domainHigher, now)
 
         let dateSet = [now, now.addingTimeInterval(-600), now.addingTimeInterval(600)]
-        let setUpdated = updated.domain(dateSet)
+        let setUpdated = updated.domain(dateSet, nice: false)
         XCTAssertEqual(setUpdated.domainLower, now.addingTimeInterval(-600))
         XCTAssertEqual(setUpdated.domainHigher, now.addingTimeInterval(600))
+
+        let setNiceUpdated = updated.domain(dateSet, nice: true)
+        XCTAssertEqual(setNiceUpdated.domainLower, now.addingTimeInterval(-600))
+        XCTAssertEqual(setNiceUpdated.domainHigher, now.addingTimeInterval(660))
     }
 
     func testTransformModifier() throws {