Fix day↔week price conversion (6.99 weekly shows as 7.00)

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 The changelog for `SuperwallKit`. Also see the [releases](https://github.com/superwall/Superwall-iOS/releases) on GitHub.
 
+## 4.15.3
+
+### Fixes
+
+- Fixes computed period prices (`weeklyPrice`, `dailyPrice`) being off by a small amount for products whose subscription period is expressed in days.
+
 ## 4.15.2
 
 ### Enhancements

Sources/SuperwallKit/Misc/Constants.swift

@@ -18,5 +18,5 @@ let sdkVersion = """
 */
 
 let sdkVersion = """
-4.15.2
+4.15.3
 """

Sources/SuperwallKit/StoreKit/Products/StoreProduct/APIStoreProduct.swift

@@ -194,7 +194,7 @@ struct APIStoreProduct: StoreProductType {
     let days: Decimal
     switch unit {
     case .day: days = Decimal(subscriptionValue)
-    case .week: days = Decimal(365) / Decimal(52) * Decimal(subscriptionValue)
+    case .week: days = Decimal(7) * Decimal(subscriptionValue)
     case .month: days = Decimal(365) / Decimal(12) * Decimal(subscriptionValue)
     case .year: days = Decimal(365 * subscriptionValue)
     @unknown default: days = 1
@@ -209,7 +209,7 @@ struct APIStoreProduct: StoreProductType {
     }
     let weeks: Decimal
     switch unit {
-    case .day: weeks = Decimal(subscriptionValue) * Decimal(52) / Decimal(365)
+    case .day: weeks = Decimal(subscriptionValue) / Decimal(7)
     case .week: weeks = Decimal(subscriptionValue)
     case .month: weeks = Decimal(52) / Decimal(12) * Decimal(subscriptionValue)
     case .year: weeks = Decimal(52 * subscriptionValue)

Sources/SuperwallKit/StoreKit/Products/StoreProduct/SK2StoreProduct.swift

@@ -263,106 +263,34 @@ struct SK2StoreProduct: StoreProductType {
   }
 
   var dailyPrice: String {
-    guard let subscriptionPeriod = underlyingSK2Product.subscription?.subscriptionPeriod else {
-      return "n/a"
-    }
-
-    let numberOfUnits = subscriptionPeriod.value
-    var periods: Decimal = 1.0
-    let inputPrice = underlyingSK2Product.price
-
-    switch subscriptionPeriod.unit {
-    case .year:
-      periods = Decimal(365 * numberOfUnits)
-    case .month:
-      periods = Decimal(365) / Decimal(12) * Decimal(numberOfUnits)
-    case .week:
-      periods = Decimal(365) / Decimal(52) * Decimal(numberOfUnits)
-    case .day:
-      periods = Decimal(numberOfUnits)
-    @unknown default:
-      periods = Decimal(numberOfUnits)
-    }
-
-    let result = (inputPrice / periods).roundedPrice()
-    return priceFormatter.string(from: NSDecimalNumber(decimal: result)) ?? "n/a"
+    return formattedComputedPrice { $0.pricePerDay(withTotalPrice: $1) }
   }
 
   var weeklyPrice: String {
-    guard let subscriptionPeriod = underlyingSK2Product.subscription?.subscriptionPeriod else {
-      return "n/a"
-    }
-
-    let numberOfUnits = subscriptionPeriod.value
-    var periods: Decimal = 1.0
-    let inputPrice = underlyingSK2Product.price
-
-    switch subscriptionPeriod.unit {
-    case .year:
-      periods = Decimal(52 * numberOfUnits)
-    case .month:
-      periods = Decimal(52) / Decimal(12) * Decimal(numberOfUnits)
-    case .week:
-      periods = Decimal(numberOfUnits)
-    case .day:
-      periods = Decimal(numberOfUnits) * Decimal(52) / Decimal(365)
-    @unknown default:
-      periods = Decimal(numberOfUnits)
-    }
-
-    let result = (inputPrice / periods).roundedPrice()
-    return priceFormatter.string(from: NSDecimalNumber(decimal: result)) ?? "n/a"
+    return formattedComputedPrice { $0.pricePerWeek(withTotalPrice: $1) }
   }
 
   var monthlyPrice: String {
-    guard let subscriptionPeriod = underlyingSK2Product.subscription?.subscriptionPeriod else {
-      return "n/a"
-    }
-
-    let numberOfUnits = subscriptionPeriod.value
-    var periods: Decimal = 1.0
-    let inputPrice = underlyingSK2Product.price
-
-    switch subscriptionPeriod.unit {
-    case .year:
-      periods = Decimal(12 * numberOfUnits)
-    case .month:
-      periods = Decimal(1 * numberOfUnits)
-    case .week:
-      periods = Decimal(numberOfUnits) * Decimal(12) / Decimal(52)
-    case .day:
-      periods = Decimal(numberOfUnits) * Decimal(12) / Decimal(365)
-    @unknown default:
-      periods = Decimal(numberOfUnits)
-    }
-
-    let result = (inputPrice / periods).roundedPrice()
-    return priceFormatter.string(from: NSDecimalNumber(decimal: result)) ?? "n/a"
+    return formattedComputedPrice { $0.pricePerMonth(withTotalPrice: $1) }
   }
 
   var yearlyPrice: String {
-    guard let subscriptionPeriod = underlyingSK2Product.subscription?.subscriptionPeriod else {
+    return formattedComputedPrice { $0.pricePerYear(withTotalPrice: $1) }
+  }
+
+  /// Formats a per-period price derived from the *normalized* subscription
+  /// period. `subscriptionPeriod` is built via `SubscriptionPeriod.from(...)`,
+  /// which applies `normalized()` — collapsing StoreKit's occasional `.day × 7`
+  /// into `.week × 1`. Without that, a weekly product reported by StoreKit in
+  /// days would divide by an approximate day↔week factor and report a
+  /// `weeklyPrice` a penny off (e.g. £6.99 → £7.00).
+  private func formattedComputedPrice(
+    _ perPeriod: (SubscriptionPeriod, Decimal) -> Decimal
+  ) -> String {
+    guard let subscriptionPeriod = subscriptionPeriod else {
       return "n/a"
     }
-
-    let numberOfUnits = subscriptionPeriod.value
-    var periods: Decimal = 1.0
-    let inputPrice = underlyingSK2Product.price
-
-    switch subscriptionPeriod.unit {
-    case .year:
-      periods = Decimal(numberOfUnits)
-    case .month:
-      periods = Decimal(numberOfUnits) / Decimal(12)
-    case .week:
-      periods = Decimal(numberOfUnits) / Decimal(52)
-    case .day:
-      periods = Decimal(numberOfUnits) / Decimal(365)
-    @unknown default:
-      periods = Decimal(numberOfUnits)
-    }
-
-    let result = (inputPrice / periods).roundedPrice()
+    let result = perPeriod(subscriptionPeriod, underlyingSK2Product.price)
     return priceFormatter.string(from: NSDecimalNumber(decimal: result)) ?? "n/a"
   }
 

Sources/SuperwallKit/StoreKit/Products/StoreProduct/StripeProductType.swift

@@ -299,7 +299,8 @@ struct StripeProductType: StoreProductType {
     }
 
     if subscriptionPeriod.unit == .week {
-      periods = Decimal(365) / Decimal(52) * Decimal(numberOfUnits)
+      // 7 days per week exactly — not 365/52.
+      periods = Decimal(7) * Decimal(numberOfUnits)
     }
 
     if subscriptionPeriod.unit == .day {
@@ -338,7 +339,8 @@ struct StripeProductType: StoreProductType {
     }
 
     if subscriptionPeriod.unit == .day {
-      periods = Decimal(numberOfUnits) * Decimal(52) / Decimal(365)
+      // 7 days per week exactly — a 7-day product is 1 week.
+      periods = Decimal(numberOfUnits) / Decimal(7)
     }
 
     let rounded = (price / periods).roundedPrice()

Sources/SuperwallKit/StoreKit/Products/StoreProduct/SubscriptionPeriod.swift

@@ -107,7 +107,7 @@ public final class SubscriptionPeriod: NSObject, Sendable {
   /// Occasionally, StoreKit seems to send back a value 7 days for a 7day trial
   /// instead of a value of 1 week for a trial of 7 days in length.
   /// Source: https://github.com/RevenueCat/react-native-purchases/issues/348
-  private func normalized() -> SubscriptionPeriod {
+  func normalized() -> SubscriptionPeriod {
     switch unit {
     case .day:
       if value.isMultiple(of: 7) {
@@ -131,7 +131,10 @@ extension SubscriptionPeriod {
     let periodsPerDay: Decimal = {
       switch self.unit {
       case .day: return 1
-      case .week: return Decimal(365) / Decimal(52)
+      // A week is exactly 7 days. Don't route through 52/365 — 52 weeks is
+      // only 364 days, so that approximation makes a 1-week product's daily
+      // price disagree with an equivalent 7-day product's.
+      case .week: return 7
       case .month: return Decimal(365) / Decimal(12)
       case .year: return 365
       }
@@ -145,7 +148,9 @@ extension SubscriptionPeriod {
   func pricePerWeek(withTotalPrice price: Decimal) -> Decimal {
     let periodsPerWeek: Decimal = {
       switch self.unit {
-      case .day: return Decimal(52) / Decimal(365)
+      // A day is exactly 1/7 of a week. The old 52/365 made a 7-day product
+      // resolve to 0.997 weeks, inflating its weekly price (e.g. 6.99 → 7.00).
+      case .day: return Decimal(1) / Decimal(7)
       case .week: return 1
       case .month: return Decimal(52) / Decimal(12)
       case .year: return 52

SuperwallKit.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
 	s.name         = "SuperwallKit"
-  s.version      = "4.15.2"
+  s.version      = "4.15.3"
 	s.summary      = "Superwall: In-App Paywalls Made Easy"
 	s.description  = "Paywall infrastructure for mobile apps :) we make things like editing your paywall and running price tests as easy as clicking a few buttons. superwall.com"
 

Tests/SuperwallKitTests/StoreKit/Products/StoreProduct/SubscriptionPeriodPriceTests.swift

@@ -57,6 +57,29 @@ struct SubscriptionPeriodPriceTests {
     #expect(dailyPrice == Decimal(string: "0.99"))
   }
 
+  @Test("Daily price for a 1-week subscription divides by exactly 7")
+  func testDailyPriceForWeeklySubscriptionDividesBySeven() {
+    // A week is exactly 7 days. Before the day↔week fix this divided by
+    // 365/52 ≈ 7.019, giving 7.00 / 7.019 ≈ 0.9973 → "0.99" — a penny too low.
+    let period = SubscriptionPeriod(value: 1, unit: .week)
+    let dailyPrice = period.pricePerDay(withTotalPrice: Decimal(string: "7.00")!)
+
+    #expect(dailyPrice == Decimal(string: "1.00"))
+  }
+
+  @Test("7-day and 1-week subscriptions produce the same daily price")
+  func testSevenDayAndOneWeekDailyPriceAreConsistent() {
+    // The two are the same duration — their derived daily price must match.
+    let price = Decimal(string: "7.00")!
+    let sevenDay = SubscriptionPeriod(value: 7, unit: .day)
+    let oneWeek = SubscriptionPeriod(value: 1, unit: .week)
+
+    #expect(
+      sevenDay.pricePerDay(withTotalPrice: price)
+        == oneWeek.pricePerDay(withTotalPrice: price)
+    )
+  }
+
   @Test("Daily price for multi-month subscription")
   func testDailyPriceForThreeMonthSubscription() {
     // $24.99/3 months should be ~$0.27/day (24.99 / 90)
@@ -119,6 +142,30 @@ struct SubscriptionPeriodPriceTests {
     #expect(weeklyPrice == Decimal(string: "4.99"))
   }
 
+  @Test("Weekly price for a 7-day subscription equals the price")
+  func testWeeklyPriceForSevenDaySubscription() {
+    // A 7-day period IS one week, so the weekly price must equal the price.
+    // Before the day↔week conversion fix this divided by (7 × 52/365) ≈ 0.9973,
+    // giving 6.99 / 0.9973 ≈ 7.009, which truncated to "7.00" — a penny too high.
+    let period = SubscriptionPeriod(value: 7, unit: .day)
+    let weeklyPrice = period.pricePerWeek(withTotalPrice: Decimal(string: "6.99")!)
+
+    #expect(weeklyPrice == Decimal(string: "6.99"))
+  }
+
+  @Test("7-day and 1-week subscriptions produce the same weekly price")
+  func testSevenDayAndOneWeekWeeklyPriceAreConsistent() {
+    // The two are the same duration — their derived weekly price must match.
+    let price = Decimal(string: "6.99")!
+    let sevenDay = SubscriptionPeriod(value: 7, unit: .day)
+    let oneWeek = SubscriptionPeriod(value: 1, unit: .week)
+
+    #expect(
+      sevenDay.pricePerWeek(withTotalPrice: price)
+        == oneWeek.pricePerWeek(withTotalPrice: price)
+    )
+  }
+
   // MARK: - Monthly Price Tests
 
   @Test("Monthly price for yearly subscription")
@@ -222,4 +269,46 @@ struct SubscriptionPeriodPriceTests {
     // 0.99 / 365 = 0.00271... rounds down to 0.00
     #expect(dailyPrice == Decimal(string: "0.00"))
   }
+
+  // MARK: - Normalization
+
+  // StoreKit sometimes reports a weekly subscription as `.day × 7` rather than
+  // `.week × 1`. `normalized()` collapses day/month multiples so the computed
+  // price logic (and `SK2StoreProduct`, which routes through it) treats a
+  // 7-day product as exactly one week — otherwise its weekly price came out a
+  // penny high (e.g. £6.99 → £7.00).
+
+  @Test("A 7-day period normalizes to 1 week")
+  func testSevenDayPeriodNormalizesToOneWeek() {
+    let normalized = SubscriptionPeriod(value: 7, unit: .day).normalized()
+
+    #expect(normalized.value == 1)
+    #expect(normalized.unit == .week)
+  }
+
+  @Test("A 14-day period normalizes to 2 weeks")
+  func testFourteenDayPeriodNormalizesToTwoWeeks() {
+    let normalized = SubscriptionPeriod(value: 14, unit: .day).normalized()
+
+    #expect(normalized.value == 2)
+    #expect(normalized.unit == .week)
+  }
+
+  @Test("A non-7-multiple day period stays in days")
+  func testThreeDayPeriodStaysInDays() {
+    let normalized = SubscriptionPeriod(value: 3, unit: .day).normalized()
+
+    #expect(normalized.value == 3)
+    #expect(normalized.unit == .day)
+  }
+
+  @Test("Normalized 7-day period yields a weekly price equal to the price")
+  func testNormalizedSevenDayWeeklyPriceEqualsPrice() {
+    // The full chain: a 7-day period normalizes to 1 week, and the weekly
+    // price of a 1-week product is the price itself.
+    let normalized = SubscriptionPeriod(value: 7, unit: .day).normalized()
+    let weeklyPrice = normalized.pricePerWeek(withTotalPrice: Decimal(string: "6.99")!)
+
+    #expect(weeklyPrice == Decimal(string: "6.99"))
+  }
 }