Akov.DataGenerator 2.0.0-alpha.1

DataGenerator

Data Generator. Give it a ⭐ if you find it useful. <hr/>

Key features:

Calculated properties

// Given: FirstName and LastName are randomly generated.
// The email is dynamically constructed based on their values using the following template:
.Property(s => s.Email).Construct(s => $"{s.FirstName}.{s.LastName}@mycompany.com") 

String templates

Templates support placeholders for number ranges, resources, and file content. For example, a template like:

"Note: [number:100-999] [resource:Firstnames] [file:lastnames.txt]" Could generate an output such as:

"Note: 137 Jessica Torres".

Decorators

Enhance the freshly generated random value using decorators.

.Property(s => s.Name)
    .Template("[resource:Nouns]")
    .Decorate(r => CapitalizeFirstLetter(r?.ToString()))

Random generation rules

Defines rules for generating values, each associated with a probability.

The probability of the main generation flow (P_m) is calculated as: P_m = 1 - ΣP_i

Where P_i represents the probability of each individual generation rule.

// Generates a negative value in the range of [-5, -1) with a probability of 0.1 (10%).
.Property(s => s.Year)
    .Range(1,5)
    .GenerationRule("NegativeYear", 0.1, _ => Random.Shared.Next(-5, -1))

Nullable rule

Defines the probability for the null value. The property type should either be nullable or have nullable reference type enabled.

// Precondition
class Student
{
    public string? FirstName {get; set; }
    public string LastName {get; set; }
}

// Great job :)
.Property(s => s.FirstName)
    .Template("[file:firstnames.txt]")
    .Nullable(0.25)

// Will throw an exception :(
.Property(s => s.FirstName)
    .Template("[file:lastnames.txt]")
    .Nullable(0.25)

Custom generators

// A custom generator should inherit from `GeneratorBase<T>`
public class PhoneGenerator : GeneratorBase<string>
{
    private const char SpecialSymbol = '#';

    public override string CreateRandomValue(Property property)
    {
        var mask = property.GetValueRule("PhoneMask") ?? "### ### ###";

        var builder = new StringBuilder();
        Random random = GetRandomInstance(property);

        foreach (var c in mask.ToString()!)
            builder.Append(c != SpecialSymbol ? c : random.Next(0, 10).ToString());

        return builder.ToString();
    }
}

// Usage
.Property(s => s.Phone)
    .UseGenerator(new PhoneGenerator())
    .ValueRule("PhoneMask", "## ## ## ##")

Generators

• BooleanGenerator
• DatetimeGenerator
• DecimalGenerator
• DoubleGenerator
• EmailGenerator
• EnumGenerator
• GuidGenerator
• IntGenerator
• IpGenerator
• PhoneGenerator
• StringGenerator

Example

var scheme = new DataScheme();

//StudentGroup
scheme.ForType<StudentGroup>()
    .Property(s => s.Name).Template("[resource:Nouns]").Decorate(r => Utility.CapitalizeFirstLetter(r?.ToString()))
    .Property(s => s.Students).Count(3, 5);

//Student
scheme.ForType<Student>()
    .Property(s => s.FirstName).Template("[resource:Firstnames]")
    .Property(s => s.LastName).Template("[file:lastnames.txt]").Nullable(0.25)
    .Property(s => s.Email).Construct(s => $"{Utility.BuildNameWithoutSpaces(s.FirstName, s.LastName)}" + 
                                           $"{TemplateProcessor.CreateValue(Random.Shared,"@[resource:Domains]")}")
    .Property(s => s.BirthDay).Range(DateTime.Today.AddYears(-60), DateTime.Today.AddYears(-16)).Nullable(0.1)
    .Property(s => s.Year).Range(1,5).GenerationRule("NegativeYear", 0.5, _ => Random.Shared.Next(-5, -1))
    .Property(s => s.Courses).Count(2,4)
    .Property(s => s.Note).Template("Note: [number:100-999] [resource:Firstnames] [file:lastnames.txt]");

//Contact
scheme.ForType<Contact>()
    .Property(s => s.Phone).UseGenerator(new PhoneGenerator()).PhoneMask("## ## ## ##")
    .Property(s => s.Address).Template("[resource:Addresses]")
    .Property(s => s.IpAddress).UseGenerator(new IpGenerator()).Nullable(0.5);

var dataGenerator = new SimpleDataGenerator(scheme);
var randomStudentCollection = dataGenerator.GenerateForType<StudentGroup>();