Jds.TestingUtils.Randomization 0.1.0

Testing Utils: Randomization

This collection of randomization test utilities supports creating test arrangements.

How to Use

All examples below use the thread-safe, static Jds.TestingUtils.Randomization.Randomizer.Shared instance of IRandomizationSource, which generates random values using System.Random.Shared. This IRandomizationSource is advised for most tests.

If a different algorithm is needed, e.g., a cryptographically strong random number generator is required, consider creating a Jds.TestingUtils.Randomization.ArrangedRandomizationSource. It uses provided Func<IEnumerable<>> delegates to supply values when requested.

If a specific set of random-seeming data is needed, consider creating a Jds.TestingUtils.Randomization.DeterministicRandomizationSource. It uses provided IEnumerable<> sources to supply values when requested.

Add Jds.TestingUtils.Randomization NuGet Package and Add using

Add Jds.TestingUtils.Randomization NuGet package to the test project.

Add the extensions to your test files with the following using statement:

using Jds.TestingUtils.Randomization;

All examples below assume the following additional using statements:

using System;
using System.Collections.Generic;
using System.Linq;

Generate Pseudo-random Numbers

• IRandomizationSource.Byte()
  • Gets a pseudo-random byte, greater than or equal to byte.MinValue, and less than byte.MaxValue.
• IRandomizationSource.ByteInRange(byte minInclusive, byte maxExclusive)
  • Gets a pseudo-random byte, greater than or equal to minInclusive, and less than maxExclusive.
• IRandomizationSource.Double()
  • Gets a pseudo-random double, using IRandomizationSource.NextDouble. The value should be greater than or equal to 0.0, and less than 1.0.
• IRandomizationSource.Float()
  • Gets a pseudo-random float, using IRandomizationSource.NextFloat. The value should be greater than or equal to 0.0, and less than 1.0.
• IRandomizationSource.Int()
  • Gets a pseudo-random int, using IRandomizationSource.NextIntInRange. The value should be greater than or equal to int.MinValue, and less than int.MaxValue.
• IRandomizationSource.IntInRange(int minInclusive, int maxExclusive)
  • Gets a pseudo-random int, using IRandomizationSource.NextIntInRange. The value should be greater than or equal to minInclusive, and less than maxExclusive.
• IRandomizationSource.IntNegative()
  • Gets a pseudo-random int, using IRandomizationSource.NextIntInRange. The value should be greater than or equal to int.MinValue, and less than 0.
• IRandomizationSource.IntPositive()
  • Gets a pseudo-random int, using IRandomizationSource.NextIntInRange. The value should be greater than or equal to 0, and less than int.MaxValue.
• IRandomizationSource.Long()
  • Gets a pseudo-random long, using IRandomizationSource.NextLongInRange. The value should be greater than or equal to long.MinValue, and less than long.MaxValue.
• IRandomizationSource.LongInRange(long minInclusive, long maxExclusive)
  • Gets a pseudo-random long, using IRandomizationSource.NextLongInRange. The value should be greater than or equal to minInclusive, and less than maxExclusive.
• IRandomizationSource.LongNegative()
  • Gets a pseudo-random long, using IRandomizationSource.NextLongInRange. The value should be greater than or equal to long.MinValue, and less than 0.
• IRandomizationSource.LongPositive()
  • Gets a pseudo-random long, using IRandomizationSource.NextLongInRange. The value should be greater than or equal to 0, and less than long.MaxValue.

Select a Random Item or Enumeration Value

• IRandomizationSource.RandomEnumValue<TEnum>()
  • Selects a pseudo-random value from the enum of type specified (TEnum).
  • Example: Randomizer.Shared.RandomEnumValue<System.Net.HttpStatusCode>()
• IRandomizationSource.RandomListItem<T>(IReadOnlyList<T> items)
• IReadOnlyList<T>.GetRandomItem<T>()
  • Selects a pseudo-random item from provided items.
  • Example: Randomizer.Shared.RandomListItem(System.Linq.Enumerable.Range(1, 20).ToArray())

Select a Weighted Random Item or Dictionary Key

• IRandomizationSource.RandomListItem<T>(IReadOnlyList<(T Item, double Weight)> weightedItems)
• IRandomizationSource.RandomListItem<T>(IReadOnlyList<(T Item, int Weight)> weightedItems)
• IReadOnlyList<(T Key, double Weight)>.GetWeightedRandomItem<T>()
• IReadOnlyList<(T Key, int Weight)>.GetWeightedRandomItem<T>()
  • Selects a pseudo-random .Item from provided weightedItems; item selection is weighted based upon relative .Weight.
  • Example:

Randomizer.Shared.WeightedRandomListItem(
  new[] { ("Sure", 1000), ("Likely", 500), ("Possible", 200), ("Unlikely", 50), ("Rare", 5), ("Apocryphal", 1) }
);

• IRandomizationSource.GetWeightedRandomKey<T>(IReadOnlyDictionary<T, double> weightedKeys)
• IRandomizationSource.GetWeightedRandomKey<T>(IReadOnlyDictionary<T, int> weightedKeys)
• IReadOnlyDictionary<T, double>.GetWeightedRandomKey<T>()
• IReadOnlyDictionary<T, int>.GetWeightedRandomKey<T>()
  • Selects a pseudo-random .Key from provided weightedItems; item selection is weighted based upon relative .Value.
  • Example:

Randomizer.Shared.WeightedRandomKey(new Dictionary<string, double>
{
  { "North", 0.4 }, { "East", 0.1 }, { "West", 0.1 }, { "South", 0.4 }
});

Generate a Random String

• IRandomizationSource.RandomString(int length, IReadOnlyList<char> chars)
  • Generates a random string of length characters, using provided chars. Random selections from chars are concatenated until reaching length characters.
• IRandomizationSource.RandomString(int length, IReadOnlyList<string> strings)
  • Generates a random string of length characters, using provided strings. Random selections from strings are concatenated until reaching length characters. The result is truncated to length characters.
• IRandomizationSource.RandomStringLatin(int length, bool uppercase = false, bool alphanumeric = false)
  • Generates a random string of length characters using ASCII Latin characters. Uses a - z by default. If uppercase, uses A - Z. If alphanumeric, also includes 0 - 9 with either casing.