VelvetCraft.Dotnet.Core 1.1.1

VelvetCraft.Dotnet.Core

Zero-dependency utility helpers for .NET 10: string extensions, collection extensions, DateTime/TimeSpan helpers, enum utilities, guard clauses, and generic comparison/interval helpers.

Installation

dotnet add package VelvetCraft.Dotnet.Core

Features

• String extensions — null/empty checks, case conversion, Base64 encode/decode, GUID validation, sanitization, substring extraction and more
• Collection extensions — null-safe enumeration helpers, predicate checks, safe list mutation utilities
• DateTime extensions — Unix timestamps, ISO 8601 formatting, month/day boundaries, range checks and day iteration
• TimeSpan extensions — time-of-day validation
• Enum extensions — read [Description] attributes, enumerate members with exclusions
• Guard clauses — Guard.NotNull(), Guard.NotEmpty(), Guard.NotNullOrWhiteSpace() — fail-fast argument validation
• ComparableHelper — generic Min<T>() / Max<T>() for any IComparable<T>
• IntervalHelper — period consistency checks and overlap calculation for DateTime ranges

String Extensions

Namespace: VelvetCraft.Dotnet.Core.Extensions

using VelvetCraft.Dotnet.Core.Extensions;

// Null / empty checks
"".IsNullOrEmpty();           // true
"  ".IsNullOrWhiteSpace();    // true
"hi".IsNullOrEmpty();         // false

// Case conversion
"HelloWorld".ToSnakeCase();   // "hello_world"
"myPropertyName".ToSnakeCase(); // "my_property_name"
"HelloWorld".ToCamelCase();   // "helloWorld"
"hello world".ToTitleCase();  // "Hello World"

// GUID helpers
"550e8400-e29b-41d4-a716-446655440000".IsGuid(); // true
"not-a-guid".ToGuid();                           // Guid.Empty

// Base64
"Hello".ToBase64();                // "SGVsbG8="
"SGVsbG8=".IsBase64();            // true
"SGVsbG8=".FromBase64();          // "Hello"

// Sanitize — trims leading/trailing newlines and whitespace, returns null when blank
"\n  value  \n".Sanitize();       // "value"
"   ".Sanitize();                 // null

// SubstringBetween — extracts text between two delimiters
"[hello]".SubstringBetween("[", "]");  // "hello"

// Case-insensitive equality
"Hello".EqualsIgnoreCase("hello");     // true

Collection Extensions

Namespace: VelvetCraft.Dotnet.Core.Extensions

using VelvetCraft.Dotnet.Core.Extensions;

List<int>? items = null;
items.IsNullOrEmpty();            // true
items.OrEmpty();                  // returns Enumerable.Empty<int>()

var list = new[] { 1, 2, 3 };
list.IsSingle();                  // false
list.IsMultiple();                // true
list.HasAny(x => x > 2);         // true

// EqualsAny — checks whether a value is contained in a set of candidates
Status.Active.EqualsAny(Status.Active, Status.Pending); // true

// Safe list mutation
var result = new List<string?>();
result.AddIfNotNull(null);        // no-op
result.AddIfNotNull("hello");     // adds "hello"

result.AddRangeIfNotEmpty(null);  // no-op
result.AddRangeIfNotEmpty(new[] { "a", "b" }); // adds both

// Order check
new[] { 1, 2, 3 }.IsOrderedBy(x => x); // true
new[] { 3, 1, 2 }.IsOrderedBy(x => x); // false

DateTime Extensions

Namespace: VelvetCraft.Dotnet.Core.Extensions

using VelvetCraft.Dotnet.Core.Extensions;

var dt = new DateTime(2026, 6, 15, 10, 30, 0, DateTimeKind.Utc);

// Unix timestamps (auto-converts non-UTC to UTC)
dt.ToUnixTimestampMs();      // 1781825400000L
dt.ToUnixTimestampSeconds(); // 1781825400

// ISO 8601
dt.ToIsoString();            // "2026-06-15T10:30:00.0000000Z"

// Month boundaries
dt.StartOfMonth();           // 2026-06-01 00:00:00
dt.EndOfMonth();             // 2026-06-30 23:59:59.999

// Day navigation
dt.StartOfNextDay();         // 2026-06-16 00:00:00

// Set time components on an existing date
dt.WithTime(0, 0, 0, 0);    // 2026-06-15 00:00:00

// Range check
dt.IsInRange(new DateTime(2026, 1, 1), new DateTime(2026, 12, 31)); // true

// Treat default (MinValue) as null
DateTime.MinValue.ParseOrNull(); // null
dt.ParseOrNull();                // dt

// Iterate each day between two dates
foreach (var day in DateTimeExtensions.EachDay(dt, dt.AddDays(2)))
    Console.WriteLine(day); // 2026-06-15, 2026-06-16, 2026-06-17

// Return the later of two values
DateTimeExtensions.Latest(dt, dt.AddHours(1)); // dt + 1 hour

TimeSpan Extensions

Namespace: VelvetCraft.Dotnet.Core.Extensions

using VelvetCraft.Dotnet.Core.Extensions;

TimeSpan.FromHours(12).IsValidTime();   // true  — within [00:00, 24:00)
TimeSpan.FromHours(25).IsValidTime();   // false
TimeSpan.FromHours(-1).IsValidTime();   // false

Enum Extensions

Namespace: VelvetCraft.Dotnet.Core.Extensions

using System.ComponentModel;
using VelvetCraft.Dotnet.Core.Extensions;

public enum Status
{
    [Description("Active user")] Active,
    [Description("Suspended")]   Suspended,
    Guest
}

Status.Active.GetDescription();    // "Active user"
Status.Guest.GetDescription();     // null (no [Description] attribute)

// Enumerate all members, optionally excluding some
foreach (var s in EnumExtensions.GetValues<Status>())
    Console.WriteLine(s);                    // Active, Suspended, Guest

foreach (var s in EnumExtensions.GetValues<Status>(Status.Guest))
    Console.WriteLine(s);                    // Active, Suspended

Guard Clauses

Namespace: VelvetCraft.Dotnet.Core.Guards

using VelvetCraft.Dotnet.Core.Guards;

public class OrderService
{
    private readonly IOrderRepository _repo;

    public OrderService(IOrderRepository repo)
    {
        // Throws ArgumentNullException if null
        _repo = Guard.NotNull(repo, nameof(repo));
    }

    public async Task ProcessAsync(string orderId, string customerId)
    {
        // Throws ArgumentNullException / ArgumentException if null or empty
        orderId    = Guard.NotEmpty(orderId, nameof(orderId));

        // Throws ArgumentNullException / ArgumentException if null, empty or whitespace
        customerId = Guard.NotNullOrWhiteSpace(customerId, nameof(customerId));

        await _repo.UpdateAsync(orderId, customerId);
    }
}

ComparableHelper

Namespace: VelvetCraft.Dotnet.Core.Helpers

Generic Min / Max for any type with a default comparer — works with int, decimal, DateTime, string, etc.

using VelvetCraft.Dotnet.Core.Helpers;

ComparableHelper.Min(3, 7);          // 3
ComparableHelper.Max("apple", "banana"); // "banana"

var earlier = new DateTime(2026, 1, 1);
var later   = new DateTime(2026, 6, 1);
ComparableHelper.Min(earlier, later);    // earlier

IntervalHelper

Namespace: VelvetCraft.Dotnet.Core.Helpers

Helpers for DateTime period overlap. Null endpoints are treated as unbounded (open-ended intervals).

using VelvetCraft.Dotnet.Core.Helpers;

var a = new DateTime(2026, 1, 1);
var b = new DateTime(2026, 6, 1);
var c = new DateTime(2026, 4, 1);
var d = new DateTime(2026, 9, 1);

// Consistency check
IntervalHelper.IsPeriodConsistent(a, b);    // true  (start <= end)
IntervalHelper.IsPeriodConsistent(b, a);    // false
IntervalHelper.IsPeriodConsistent(null, b); // true  (open start)

// Overlap detection (exclusive on touching boundaries)
IntervalHelper.PeriodsOverlap(a, b, c, d);  // true  — [Jan→Jun] overlaps [Apr→Sep]
IntervalHelper.PeriodsOverlap(a, b, b, d);  // false — touching boundaries do not overlap

// Overlap duration
IntervalHelper.GetOverlapDuration(a, b, c, d);
// TimeSpan of ~61 days (Apr 1 → Jun 1)

Requirements

• .NET 10.0+

License

MIT — see LICENSE