Merge pull request #1 from bolorundurowb/develop

release: v1.0.2

.travis.yml

@@ -1,9 +1,12 @@
 language: csharp
 solution: shortid.sln
 mono:
-  - 4.0.0
+  - latest
 install:
   - nuget restore shortid.sln
   - cd ../../bolorundurowb/shortid
 script:
-  - xbuild /p:Configuration=Release shortid.sln
+  - xbuild /p:Configuration=Debug shortid.sln
+after_success:
+  - nuget install NUnit.Runners -Version 3.4.1
+  - mono ./NUnit.ConsoleRunner.3.4.1/tools/nunit3-console.exe ./shortid.Test/bin/Debug/shortid.Test.dll

README.md

@@ -7,6 +7,7 @@
 A csharp library to generate completely random short id's. they can be used as primary keys or unique identifiers. This library is different in that you can specify the length of the id's generated.
 
 ## How to use
+
 To make use of the `shortid`, add it to your project via the Nuget package manager UI or console via this command:
 
 ```
@@ -56,4 +57,33 @@ string id = ShortId.Generate(true, false, 12);
 // id = VvoCDPazES_w
 ```
 
-**NOTE: when specifying the desired length, shorter lengths increase the possibility thata duplicate id would be generated**
+**NOTE: when specifying the desired length, shorter lengths increase the possibility thata duplicate id would be generated**
+
+
+## Customize ShortId
+
+`ShortId` has several features that help with customizing the ids generated. Characters sets can be introduced and the random number generator can be seeded.
+
+To change the character set in use, run the following:
+
+```csharp
+string characters = //whatever you want;
+ShortId.SetCharacters(characters);
+```
+
+**NOTE: the new character set must number `null`, an empty string or whitespace. Also, all whitespace characters would be removed, finally the character set cannot be less than 20 characters.**
+
+`ShortId` also allows the seed for the random number generator to be set.
+
+To set the seed, run the following:
+
+```csharp
+int seed = 1939048828;
+ShortId.SetSeed(seed);
+```
+
+Finally, `ShortId` allows for all customizations to be reset using the following:
+
+```csharp
+ShortId.Reset();
+```

shortid.Test/ShortId.Tests.cs

@@ -1,4 +1,5 @@
-using System.Linq;
+using System;
+using System.Linq;
 using NUnit.Framework;
 
 namespace shortid.Test
@@ -41,5 +42,40 @@ public void GenerateCreatesIdsOfASpecifiedLength()
             id = ShortId.Generate(false, true, 8);
             Assert.AreEqual(id.Length, 8);
         }
+
+        [Test]
+        public void SetSeedThrowsWhenCharacterSetIsEmptyOrNull()
+        {
+            string seed = String.Empty;
+            Assert.Throws<ArgumentException>(delegate
+            {
+                ShortId.SetCharacters(seed);
+            });
+        }
+
+        [Test]
+        public void SetSeedThrowsWhenCharacterSetIsLessThan20Characters()
+        {
+            string seed = "783ujrcuei039kj4";
+            Assert.Throws<InvalidOperationException>(delegate
+            {
+                ShortId.SetCharacters(seed);
+            });
+        }
+
+        [Test]
+        public void ResetIsStable()
+        {
+            Assert.DoesNotThrow(ShortId.Reset);
+        }
+
+        [Test]
+        public void SetSeedIsStable()
+        {
+            Assert.DoesNotThrow(delegate
+            {
+                ShortId.Generate(0);
+            });
+        }
     }
 }

shortid/ShortId.cs

@@ -4,12 +4,13 @@ namespace shortid
 {
     public class ShortId
     {
-        private static readonly Random Random = new Random();
+        private static Random _random = new Random();
         private const string Capitals = "ABCDEFGHIJKLMNOPQRSTUVWXY";
         private const string Smalls = "abcdefghjlkmnopqrstuvwxyz";
         private const string Numbers = "0123456789";
         private const string Specials = "-_";
-
+        private static string _pool = $"{Smalls}{Capitals}";
+
         /// <summary>
         /// Generates a random string of varying length
         /// </summary>
@@ -18,23 +19,23 @@ public class ShortId
         /// <returns>A random string</returns>
         public static string Generate(bool useNumbers = false, bool useSpecial = true)
         {
-            int length = Random.Next(7, 15);
+            int length = _random.Next(7, 15);
             return Generate(useNumbers, useSpecial, length);
         }
 
         /// <summary>
-        /// Generates a random string of a specified length
+        /// Generates a random string of a specified length with the option to add numbers and special characters
         /// </summary>
         /// <param name="useNumbers">Whether or not numbers are included in the string</param>
         /// <param name="useSpecial">Whether or not special characters are included</param>
         /// <param name="length">The length of the generated string</param>
         /// <returns>A random string</returns>
         public static string Generate(bool useNumbers, bool useSpecial, int length)
         {
-            string pool = $"{Capitals}{Smalls}";
+            string pool = _pool;
             if (useNumbers)
             {
-                pool += Numbers;
+                pool = Numbers + pool;
             }
             if (useSpecial)
             {
@@ -44,7 +45,7 @@ public static string Generate(bool useNumbers, bool useSpecial, int length)
             string output = string.Empty;
             for (int i = 0; i < length; i++)
             {
-                int charIndex = Random.Next(0, pool.Length);
+                int charIndex = _random.Next(0, pool.Length);
                 output += pool[charIndex];
             }
             return output;
@@ -59,5 +60,49 @@ public static string Generate(int length)
         {
             return Generate(false, true, length);
         }
+
+        /// <summary>
+        /// Changes the character set that id's are generated from
+        /// </summary>
+        /// <param name="characters">The new character set</param>
+        /// <exception cref="InvalidOperationException">Thrown when the new character set is less than 20 characters</exception>
+        public static void SetCharacters(string characters)
+        {
+            if (string.IsNullOrWhiteSpace(characters))
+            {
+                throw new ArgumentException("The replacement characters must not be null or empty.");
+            }
+
+            characters = characters
+                .Replace(" ", "")
+                .Replace("\t", "")
+                .Replace("\n", "")
+                .Replace("\r", "");
+
+            if (characters.Length < 20)
+            {
+                throw new InvalidOperationException(
+                    "The replacement characters must be at least 20 letters in length and without spaces.");
+            }
+            _pool = characters;
+        }
+
+        /// <summary>
+        /// Sets the seed that the random generator works with.
+        /// </summary>
+        /// <param name="seed">The seed for the random number generator</param>
+        public static void SetSeed(int seed)
+        {
+            _random = new Random(seed);
+        }
+
+        /// <summary>
+        /// Resets the random number generator and character set
+        /// </summary>
+        public static void Reset()
+        {
+            _random = new Random();
+            _pool = $"{Smalls}{Capitals}";
+        }
     }
 }