From fda668dcaf7792b3e58b053176ff00b4c4c03d8e Mon Sep 17 00:00:00 2001
From: Dmitrijs Minajevs <dmitrijs.minajevs@outlook.com>
Date: Thu, 7 Oct 2021 16:35:00 +0300
Subject: [PATCH] feat(card): add support for Switch (#63)

* feat(card): add support for Switch
* fix(Switch): fix switch card length options
* fix(Switch): fix Switch test inline data
---
 src/Dedge.Cardizer/Dedge.Cardizer.fs | 38 ++++++++++++++++++++++++++++
 src/Tests/Tests.fs                   | 24 ++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/src/Dedge.Cardizer/Dedge.Cardizer.fs b/src/Dedge.Cardizer/Dedge.Cardizer.fs
index 6ab06e9..e1135a2 100644
--- a/src/Dedge.Cardizer/Dedge.Cardizer.fs
+++ b/src/Dedge.Cardizer/Dedge.Cardizer.fs
@@ -32,6 +32,12 @@ type From16To19 =
     | Eightteen = 18
     | Nineteen = 19
 
+type From16To19Skip17 =
+    | Random = 0
+    | Sixteen = 16
+    | Eighteen = 18
+    | Nineteen = 19
+
 type DinersClubInternationalLengthOptions =
     | Random = 0
     | Fourteen = 14
@@ -558,6 +564,38 @@ type Cardizer =
 
         Cardizer.GenerateCard prefix 16
 
+    /// <summary>Returns a random Switch number.</summary>
+    /// <returns>Random Switch number</returns>
+    /// <example>
+    /// This sample shows how to call the <see cref="NextSwitch"/> method.
+    /// <code>
+    /// void PrintSwitch()
+    /// {
+    ///    Console.WriteLine(Cardizer.NextSwitch());
+    ///    Console.WriteLine(Cardizer.NextSwitch()); // randomized between 16, 18 or 19
+    ///    Console.WriteLine(Cardizer.NextSwitch(From16To19Skip17.Random)); // randomized between 16, 18 or 19
+    ///    Console.WriteLine(Cardizer.NextSwitch(From16To19Skip17.Sixteen));
+    /// }
+    /// </code>
+    /// </example>
+    static member NextSwitch([<Optional; DefaultParameterValue(From16To19Skip17.Random)>] switchLengthOption) =
+        let length =
+            match switchLengthOption with
+            | From16To19Skip17.Random -> [ 16; 18; 19 ].[Cardizer.next 3]
+            | _ -> int switchLengthOption
+
+        let prefix =
+            [ [ 4; 9; 0; 3 ]
+              [ 4; 9; 0; 5 ]
+              [ 4; 9; 1; 1 ]
+              [ 4; 9; 3; 6 ]
+              [ 5; 6; 4; 1; 8; 2 ]
+              [ 6; 3; 3; 1; 1; 0 ]
+              [ 6; 3; 3; 3 ]
+              [ 6; 7; 5; 9 ] ].[Cardizer.next 8]
+
+        Cardizer.GenerateCard prefix length
+
     /// <summary>Returns a random Visa Electron number.</summary>
     /// <returns>Random Visa Electron number</returns>
     /// <example>
diff --git a/src/Tests/Tests.fs b/src/Tests/Tests.fs
index fd937f2..d6afd4d 100644
--- a/src/Tests/Tests.fs
+++ b/src/Tests/Tests.fs
@@ -308,6 +308,30 @@ let ``Should generate valid InstaPayment`` () =
     card |> should haveLength 16
     card |> luhn |> should be LuhnCheck
 
+[<Theory>]
+[<InlineData(From16To19Skip17.Sixteen, 16)>]
+[<InlineData(From16To19Skip17.Eighteen, 18)>]
+[<InlineData(From16To19Skip17.Nineteen, 19)>]
+let ``Should generate valid Switch`` length expectedLength =
+    let card = Cardizer.NextSwitch length
+
+    let shortPrefix = card.Substring(0, 4) |> int
+    let longPrefix = card.Substring(0, 6) |> int
+
+    let prefixInRange =
+        shortPrefix = 4903
+        || shortPrefix = 4905
+        || shortPrefix = 4911
+        || shortPrefix = 4936
+        || shortPrefix = 6333
+        || shortPrefix = 6759
+        || longPrefix = 564182
+        || longPrefix = 633110
+
+    prefixInRange |> should be True
+    card |> should haveLength expectedLength
+    card |> luhn |> should be LuhnCheck
+
 [<Fact>]
 let ``Should generate valid Visa Electron`` () =
     let card = Cardizer.NextVisaElectron()