lib12 is a set of various classes and extensions methods that I accumulated over years of working on different projects. Most of them can help you write code faster like different options to check objects state, some will help you work with collections, reflection or text. Some a little more sophisticated like fluent query builder or mathematical formula parser.

Current version available on nuget - https://www.nuget.org/packages/lib12 My blog describing library setup and content - https://kkalinowski.net/2018/10/07/lib12-my-helper-library/

Programming language: C#
License: MIT License
Tags: Extensions     Netstandard     HelperMethods    
Latest version: v2.6

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The purpose of lib12 is to replace common code present in any .NET project with one NuGet. This is done by extending the standard API in three ways:

  • with extensions methods to standard types like string.IsNotNullAndNotEmpty, string.RemoveDiacritics, IEnumerable.LeftJoin or DateTime.GetWeek
  • by giving developer new constructs like CollectionFactory or Execution classes
  • by adding not standard utilities that could be very useful in specific circumstances like fluent SQL builder or reverse polish notation formula parser All of these functionalities are created with a wide array of possible use cases in mind and covered with unit tests

Current version available on nuget - https://www.nuget.org/packages/lib12

My blog describing how I work on library and its content - https://kkalinowski.net/2018/10/07/lib12-my-helper-library/

Table of Contents

  1. Data
    1. Fluent SQL query builder
    2. Dummy and random data
    3. Geopolitical data
    4. XML extensions
  2. Mathematical functions
  3. Collections
  4. Reflection
    1. Extensions
    2. Creation by enum
  5. Extensions methods
  6. Utilities
  7. Checking utilities

Fluent SQL query builder

Namespace - lib12.Data.QueryBuilding

In spite of overwhelming popularity of various ORMs you still have to write some SQL query from time to time. Maintaining and storing those queries can be tricky. To help with that I created fluent SQL query builder. It supports most important SQL keywords for select, insert, update and delete. Using it is quite simple:

var select = SqlBuilder.Select.Fields(fields).From("products", "p")
    .Join("groups", "g", "p.group_id", "g.id")
    .Join("stores", "s", "g.id", "s.group_id", JoinType.Left)
    .Where("price", Compare.GreaterThan, 100).And.Where("price", Compare.LessOrEquals, 1000)
    .Or.Where("code", Compare.Like, "a%")

var insert = SqlBuilder.Insert.Into("product").Columns("type", "price", "name").Values(4, 5, "test").Build();

var batchInsertQuery = SqlBuilder.Insert.Into("product").Columns("Prop1", "Prop2").Batch(
        new Values{Prop1 = "test", Prop2 = 21},
        new Values{Prop1 = "test2", Prop2 = 8}

var insertIntoSelect = SqlBuilder.Insert.Into("product").Columns("name","price")

var update = SqlBuilder.Update.Table("product").Set("price", 5).Set("name", "test").OpenBracket()
    .Where("price", Compare.Equals, 1).And.Where("type", Compare.Equals, 3).CloseBracket()
    .Or.Where("type", Compare.NotEquals, 3)

var delete = SqlBuilder.Delete.From("product").OpenBracket()
    .Where("price", Compare.Equals, 1).And.Where("type", Compare.Equals, 3).CloseBracket()
    .Or.Where("type", Compare.NotEquals, 3)

Dummy and random data

Namespace - lib12.Data.Random

Sometimes when you start developing new project you don't have data to test your solution. lib12 contains classes that will help you to quickly solve this problem. Rand contains methods to quickly generate collection of random data:

public class ClassToGenerate
    public enum EnumToGenerate

    public class Nested
        public string NestedText { get; set; }

    public string Text { get; set; }
    public EnumToGenerate Enum { get; set; }
    public bool Bool { get; set; }
    public int Int { get; set; }
    public double Double { get; set; }
    public int NumberThatShouldntBeSet { get; } = 12;
    public int NumberImpossibleToSet { get { return 12; } }
    public Nested NestedClass { get; set; }

var generated = Rand.NextArrayOf<ClassToGenerate>(CollectionSize);

lib12.Data.Random contains also methods from System.Random class and additional methods for generating bool, char, string, enums and DateTime in one easy to use static Rand class. Also FakeData class contains preprogramed set of names, companies, geodata to quickly generate useful data for your application tests.

Geopolitical data

lib12.Data.Geopolitical.CountryRepository contains list of countries (AllCountries property) and also easily accessible objects (SingleCountries property). Apart from name you can also get information about languages, capital, currencies and more.

XML extensions

Contains extensions methods for Xml classes to create xmls in fluent way.

Mathematical functions

Namespace - lib12.Mathematics

Formula class use Reverse Polish Notation to parse and compute mathematical expressions:

var formula = new Formula("-12*3 + (5-3)*6 + 9/(4-1)");
var result = formula.Evaluate();

This class understands variables, so you can compile it once and use for many computations:

var formula = new Formula("a*(5-b)");
formula.Evaluate(new { a = 10, b = 3 });

Mathematics namespace contains also Math2 class which contains many helper functions like Next, Prev, IsEven or IsOdd.


Namespace - lib12.Collections

  • IEnumerableExtension contains methods that easier working with standard collections like Foreach, IsNullOrEmpty, Recover (which acts as null pattern object simplifying null checking), ToDelimitedString, IntersectBy, MaxBy, LeftJoin, etc.
  • lib12.Collections.ICollectionExtension - AddRange, RemoveRange, RemoveBy
  • lib12.Collections.IDictionaryExtension - GetValueOrDefault, Recover, Concat and ToReadOnlyDictionary
  • lib12.Collections.ArrayExtension - methods to Flatten multi dimensional arrays
  • lib12.Collections.CollectionFactory - creates collections in functional way
  • lib12.Collections.Empty - creates empty collections using fluent syntax
  • lib12.Collections.Packing - contains class Pack to quickly pack set of loose objects into collection and extension methods for single object to do that
  • lib12.Collections.Paging - contains extension methods GetPage, GetNumberOfPages and GetPageItems to simplify working with paging



Namespace - lib12.Reflection

Reflection namespace contains a lot of useful extension methods that make working with .NET reflection mechanism easier and more straightforward:

  • easier work with attributes - all reflection entities like Type, FieldInfo, PropertyInfo, etc. and also enum fields contains method GetAttribute<> for retrieving decorating attribute and also IsMarkedWithAttribute<> to check if entity is decorated with given attribute
  • checking properties of constructs - with methods like IsStatic, IsNullable, IsNumber, IsImplementingInterface and more you can quickly check more advance properties of types, fields and properties
  • accessing object data through reflection - with methods like GetConstants, GetPropertyValueByName or GetFieldValueValueByName
  • manipulating objects - creating objects with CreateInstance<>, calling methods with CallMethodByName or setting object state with SetPropertyValueByName

Creation by enum

Namespace - lib12.Reflection.CreationByEnum

This unique mechanism allows you to create whole objects based on current data state. It could be useful to i.e. create strategies to handle data based on single value:

public enum OrderState

public class Order
    public OrderStatus Status { get; set; }


var strategy = order.Status.CreateType<IStrategy>();

Extensions methods

Namespace - lib12.Extensions

  • String - methods like EqualsCaseInsensitive, Truncate, ContainsCaseInsensitive, RemoveDiacritics or GetNumberOfOccurrences
  • DateTime - allows to manipulate weeks and quarter, get start and end of week and month, get persons age or check date (IsWorkday, IsWeekend, IsInPast, IsInFuture)
  • Nullable bool - quick checks remove redundant code like IsTrue or IsNullOrFalse
  • Exception - GetInnerExceptions and GetMostInnerException
  • Func - method to convert function to non generic version


  • lib12.Utlity.Comparing - contains generic PropertyOrderComparer and PropertyEqualityComparer that implements IComparer and IEqualityComparer respectively so for simple one property checks you don't have to implement whole Comparer class
  • lib12.Utility.Execution - utilities to work with function calls - Repeat, Benchmark, Retry and Memoize
  • lib12.Utility.Range - generic class for dealing with ranges
  • lib12.Utility.IoHelper - additional methods for IO
  • lib12.Utility.Logger - simple logger, that doesn't need additional configuration
  • lib12.Utility.UnknownEnumException - exception to better interpret missing case for enum

Checking utilities

Namespace - lib12.Checking

Contains Check class to quickly simplify null checking on set objects like Check.AllAreNull or Check.AnyIsNull. This namespace also contains extensions for equality check against set of objects like object.IsAnyOf(object1, object2, object3)