CoreSuite.Helpers 1.0.2

CoreSuite.Helpers

A lightweight collection of reusable .NET 8 helpers for common application tasks, included in CoreSuite.

Overview

CoreSuite.Helpers centralizes small, frequently repeated operations behind a consistent set of shared helper classes. It includes utilities for reflection, enumeration metadata, file-system operations, Brazilian data formats, Unix timestamps, SQL command inspection, internet connectivity checks, mathematical operations, and text generation.

The package targets plain .NET 8 and does not depend on Windows Forms or third-party packages, making it suitable for desktop applications, services, console applications, class libraries, and other .NET projects.

Key features

• Retrieve custom attributes from public shared or static members.
• Format and validate Brazilian CEP, phone, CPF, CNPJ, and email values.
• Print an expanded representation of a parameterized DbCommand for debugging.
• Convert between Unix epoch milliseconds and Brasília date/time.
• Read DescriptionAttribute metadata from enum values.
• Enumerate and filter enum members through reflection.
• Check whether files are locked and attempt safe file or directory deletion.
• Test internet connectivity synchronously or asynchronously.
• Find the nearest decimal value in a sample set.
• Evaluate simple, fully parenthesized arithmetic expressions.
• Inspect collection properties and invoke methods through reflection.
• Create runtime types with dynamically generated properties.
• Generate random strings and file names.
• Extract simple string values from compact JSON text.

Requirements

• .NET 8 (net8.0)
• A reference to the CoreSuite.Helpers package, project, or assembly

The project uses only .NET base class library APIs and currently declares no external NuGet dependencies.

Installation

NuGet Package Manager

Install-Package CoreSuite.Helpers

.NET CLI

dotnet add package CoreSuite.Helpers

Project reference

When using the CoreSuite source code directly, add the project reference below:

<ItemGroup>
  <ProjectReference Include="..\Helpers\Helpers.vbproj" />
</ItemGroup>

Namespace

All public types are available through the following namespace:

Imports CoreSuite.Helpers

Quick start

Imports CoreSuite.Helpers
Dim Cep As String = BrazilianFormatHelper.GetFormatedZipCode("12345678")
Dim IsCpfValid As Boolean = BrazilianFormatHelper.IsValidNaturalEntityDocument("52998224725")
Dim BrasiliaNow As Date = DateTimeHelper.Now()
Dim ClosestValue As Decimal = MathHelper.ApproximateValue({10D, 20D, 30D}, 24D)
Dim Token As String = TextHelper.GetRandomString(4, 4, "-", New List(Of CharFilter) From {CharFilter.UppercaseAlphabetic, CharFilter.Numeric})

API summary

Helper	Purpose
AttributeHelper	Retrieves custom attributes from public shared or static members.
BrazilianFormatHelper	Formats and validates Brazilian postal, phone, document, and email values.
DatabaseHelper	Prints a readable representation of a parameterized database command.
DateTimeHelper	Converts Unix milliseconds and retrieves the current Brasília date/time.
EnumHelper	Reads enum values, fields, and DescriptionAttribute metadata.
FileHelper	Checks file locks and attempts file-system deletions.
InternetHelper	Checks whether one of several public HTTP endpoints is reachable.
MathHelper	Finds approximate sample values and evaluates simple arithmetic expressions.
ReflectionHelper	Inspects collections, invokes methods, and creates dynamic runtime types.
TextHelper	Generates random text and extracts simple values from JSON-like text.

AttributeHelper

AttributeHelper retrieves a custom attribute from a named public shared or static member.

GetAttribute(Of TAttribute)

Public Shared Function GetAttribute(Of TAttribute As Attribute)(Type As Type, MemberName As String) As TAttribute

The method searches with BindingFlags.Public Or BindingFlags.Static. It is particularly useful for enum fields and other public static members.

Imports System.ComponentModel
Imports CoreSuite.Helpers
Public Enum OrderStatus
    <Description("Waiting for payment")>
    Pending
    <Description("Completed")>
    Completed
End Enum
Dim Attribute As DescriptionAttribute = AttributeHelper.GetAttribute(Of DescriptionAttribute)(GetType(OrderStatus), NameOf(OrderStatus.Pending))
Dim Description As String = Attribute?.Description

The method returns Nothing when the member exists but does not contain the requested attribute. It throws an exception when the type or member name is invalid, or when the named member is not found.

BrazilianFormatHelper

BrazilianFormatHelper contains formatting and validation methods for common Brazilian values.

CEP

Format a CEP

Dim FormattedCep As String = BrazilianFormatHelper.GetFormatedZipCode("12345678")

Current output format:

12.345-678

When the normalized value does not contain exactly eight digits, the original input is returned.

Validate a CEP

Dim IsValid As Boolean = BrazilianFormatHelper.IsValidZipCode("12345-678")

The method removes dots, hyphens, and spaces before checking for exactly eight numeric digits.

Phone numbers

Detect the phone format

Dim Format As PhoneFormat = BrazilianFormatHelper.GetWhichPhoneFormat("11987654321")

Supported values:

Value	Expected normalized structure
FixedPhone	Ten digits containing a supported two-digit DDD.
CellPhone	Eleven digits containing a supported DDD followed by 9.
SpecialPhone	Eleven digits beginning with 0300, 0500, 0800, or 0900.
InvalidPhone	Any unsupported format.

Format a phone number

Dim Mobile As String = BrazilianFormatHelper.GetFormatedPhoneNumber("11987654321")
Dim Landline As String = BrazilianFormatHelper.GetFormatedPhoneNumber("1134567890")
Dim Service As String = BrazilianFormatHelper.GetFormatedPhoneNumber("08001234567")

Typical results:

(11) 9 8765-4321
(11) 3456-7890
0800-123-4567

Unsupported values are returned in normalized form, with parentheses, hyphens, and spaces removed.

CPF and CNPJ

Apply a document mask

Dim Cpf As String = BrazilianFormatHelper.GetFormatedDocument("52998224725")
Dim Cnpj As String = BrazilianFormatHelper.GetFormatedDocument("11222333000181")

Typical results:

529.982.247-25
11.222.333/0001-81

Only numeric values containing exactly 11 or 14 digits receive a mask.

Validate a CPF

Dim IsValidCpf As Boolean = BrazilianFormatHelper.IsValidNaturalEntityDocument("529.982.247-25")

The method normalizes the value, rejects known repeated-digit values, and validates both CPF check digits.

Validate a CNPJ

Dim IsValidCnpj As Boolean = BrazilianFormatHelper.IsValidLegalEntityDocument("11.222.333/0001-81")

The method normalizes the value and validates both CNPJ check digits.

Email

Dim IsValidEmail As Boolean = BrazilianFormatHelper.IsValidEmail("user@example.com")

Email validation is performed through the regular expression embedded in the helper. It is intended as a structural application-level check and does not verify whether the mailbox or domain actually exists.

DatabaseHelper

DatabaseHelper provides a debugging utility for ADO.NET commands.

DebugQuery

Imports System.Data.Common
Imports CoreSuite.Helpers
Private Sub PrintCommand(Command As DbCommand)
    DatabaseHelper.DebugQuery(Command)
End Sub

The method starts with Command.CommandText, replaces each parameter name with its value surrounded by single quotes, and writes the result through Debug.Print.

DateTimeHelper

DateTimeHelper converts Unix epoch milliseconds to and from the Brasília time zone and can return the current Brasília date/time independently of the machine's local time zone.

The implementation resolves the time zone using the identifier:

E. South America Standard Time

Convert Unix milliseconds to Brasília time

Dim BrasiliaDate As Date = DateTimeHelper.DateFromMilliseconds(0)

The input represents milliseconds elapsed since 1970-01-01 00:00:00 UTC. The result is converted from UTC to the configured Brasília time zone.

Convert Brasília time to Unix milliseconds

Dim Timestamp As Long = DateTimeHelper.MillisecondsFromDate(New Date(2026, 8, 1, 12, 0, 0))

The supplied Date is treated as an unspecified date/time belonging to the Brasília time zone and is converted to UTC before calculating the Unix timestamp.

Get the current Brasília time

Dim CurrentDate As Date = DateTimeHelper.Now()

This method uses DateTime.UtcNow as its source and converts it to Brasília time.

EnumHelper

EnumHelper simplifies access to enum members and their DescriptionAttribute metadata.

Example enum

Imports System.ComponentModel
Public Enum PaymentStatus
    <Description("Waiting")>
    Pending
    <Description("Paid")>
    Paid
    Cancelled
End Enum

Find a value by description

Dim Status As PaymentStatus = EnumHelper.GetEnumValue(Of PaymentStatus)("Paid")

The comparison is exact and case-sensitive. Only members containing DescriptionAttribute are considered. An exception is thrown when no matching description exists.

Get all enum values

Dim Statuses As IEnumerable(Of PaymentStatus) = EnumHelper.GetEnumItems(Of PaymentStatus)()

Filter enum values by field metadata

Dim Filtered As IEnumerable(Of PaymentStatus) = EnumHelper.GetEnumItems(Of PaymentStatus)(Function(Field) Field.Name <> NameOf(PaymentStatus.Cancelled))

The predicate receives the FieldInfo associated with each public static enum member.

Get all descriptions

Dim Descriptions As IEnumerable(Of String) = EnumHelper.GetEnumDescriptions(Of PaymentStatus)()

A member without DescriptionAttribute contributes String.Empty to the returned sequence.

Get one description

Dim Description As String = EnumHelper.GetEnumDescription(PaymentStatus.Pending)

The method returns Nothing when the selected enum member has no DescriptionAttribute.

FileHelper

FileHelper contains small helpers for checking exclusive file access and attempting deletion operations.

Check whether a file is locked

Imports System.IO
Dim File As New FileInfo("C:\Data\report.txt")
Dim IsLocked As Boolean = FileHelper.IsFileLocked(File)

The helper attempts to open the file for reading with FileShare.None. An IOException is interpreted as the file being locked or unavailable for exclusive access.

Attempt to delete a file

Dim Deleted As Boolean = FileHelper.TryDeleteFile(New FileInfo("C:\Data\temporary.txt"))

The method attempts to acquire exclusive read/write access and then deletes the file. It returns False when an IOException occurs.

Attempt to delete a directory recursively

Dim Deleted As Boolean = FileHelper.TryDeleteDirectory(New DirectoryInfo("C:\Data\Temporary"))

The directory and all its contents are deleted through DirectoryInfo.Delete(True). The method returns False when an IOException occurs.

InternetHelper

InternetHelper checks connectivity by contacting a predefined collection of public HTTPS endpoints. The current list includes Google, Microsoft, Facebook, AWS, Cloudflare, GitHub, and YouTube.

A shared HttpClient is used with a three-second timeout per request.

Synchronous check

Dim IsOnline As Boolean = InternetHelper.IsInternetAvailable()

The synchronous method sends an HTTP HEAD request to each endpoint until one returns a successful status code.

Asynchronous check

Private Async Function CheckConnectionAsync() As Task(Of Boolean)
    Return Await InternetHelper.IsInternetAvailableAsync()
End Function

The asynchronous method sends GET requests with ResponseHeadersRead and returns as soon as one endpoint responds successfully.

A False result means none of the configured endpoints returned a successful response. It does not necessarily prove that every network resource is unavailable; proxies, DNS settings, firewalls, endpoint blocking, or temporary remote failures can also affect the result.

MathHelper

MathHelper provides nearest-value selection and a lightweight arithmetic evaluator.

Find the closest sample value

Dim Samples As Decimal() = {5D, 10D, 25D, 50D}
Dim Result As Decimal = MathHelper.ApproximateValue(Samples, 18D)

The result is 25 because it has the smallest absolute difference from 18. When two samples have the same difference, the first matching value is returned.

The sample array must contain at least one item.

Evaluate a simple expression

Dim Result As Double = MathHelper.EvaluateExpression("((2*3)+4)")

The current evaluator processes one character at a time and is best treated as a minimal implementation for fully parenthesized expressions with single-digit operands and the operators +, -, *, and /.

ReflectionHelper

ReflectionHelper contains utilities for inspecting collection properties, invoking methods, and creating types dynamically at runtime.

Detect a collection property

Imports System.Reflection
Dim PropertyInfo As PropertyInfo = GetType(Customer).GetProperty(NameOf(Customer.Orders))
Dim IsCollection As Boolean = ReflectionHelper.IsCollection(PropertyInfo)

A property is considered a collection when its type implements IEnumerable. String is explicitly excluded.

Get the element type of an indexed collection

Dim ItemType As Type = ReflectionHelper.GetCollectionPropertyType(PropertyInfo)

An overload accepts a Type directly:

Dim ItemType As Type = ReflectionHelper.GetCollectionPropertyType(GetType(List(Of Customer)))

The implementation locates an integer indexer named get_Item. It is intended for indexed collection types such as List(Of T) and can fail for non-indexed enumerables.

Invoke a method

Imports System.Reflection
Dim Flags As BindingFlags = BindingFlags.Instance Or BindingFlags.Public Or BindingFlags.NonPublic
Dim Result As Object = ReflectionHelper.InvokeMethod(Service, "Calculate", Flags, 10, 20)

The helper searches the runtime type and then its base types. Parameter matching uses the exact runtime type of each supplied argument. It returns Nothing when no matching method is found or when the invoked method has no return value.

Create a runtime type

Dim PropertyNames As New List(Of String) From {"Id", "Name"}
Dim PropertyTypes As New List(Of Type) From {GetType(Integer), GetType(String)}
Dim RuntimeType As Type = ReflectionHelper.GetRunTimeType(PropertyNames, PropertyTypes)
Dim Instance As Object = Activator.CreateInstance(RuntimeType)
RuntimeType.GetProperty("Id").SetValue(Instance, 10)
RuntimeType.GetProperty("Name").SetValue(Instance, "Alice")

The generated type contains:

• a public parameterless constructor;
• one private backing field per property;
• public getter and setter methods;
• public properties using the supplied names and types.

The property-name and property-type lists must have the same number of elements.

TextHelper

TextHelper provides random text generation, random file-name generation, and a lightweight string-based JSON value extractor.

Generate a random string

Dim Filters As New List(Of CharFilter) From {
    CharFilter.UppercaseAlphabetic,
    CharFilter.Numeric
}
Dim Code As String = TextHelper.GetRandomString(3, 4, "-", Filters)

Example shape:

A7KD-92QX-M4PL

Parameters:

Parameter	Description
SetCount	Number of groups to generate.
CharsPerSet	Number of characters in each group.
SetSeparator	Text inserted between groups.
PossibleChars	Character categories used to build the available character set.

Supported CharFilter values:

Value	Characters
Alphanumeric	0-9, A-Z, and a-z
Numeric	0-9
UppercaseAlphabetic	A-Z
LowercaseAlphabetic	a-z
SpecialCharacters	Common punctuation and symbols
Hexadecimal	0-9 and A-F

Duplicate filter entries are removed before the character set is constructed.

Generate a random file name

Dim FileName As String = TextHelper.GetRandomFileName(".tmp")

The result combines:

• the current date and time using ddMMyyyyHHmmss;
• a GUID without separators;
• the random portion generated by Path.GetRandomFileName;
• the supplied extension text.

The extension is appended exactly as supplied, so include the leading dot when required.

Extract a simple JSON string value

Dim Json As String = "{""name"":""Alice"",""status"":""active""}"
Dim Name As String = TextHelper.ExtractJsonValue(Json, "name")

The method returns Alice for the example above.

Error handling and input expectations

The helpers are intentionally small and generally expose the behavior of the underlying .NET APIs. Unless a method explicitly catches an exception or documents a fallback, callers should provide valid, non-Nothing arguments and handle relevant exceptions at the application boundary.

Common examples include:

• Brazilian formatting methods expect non-Nothing strings.
• MathHelper.ApproximateValue expects a non-empty sample array.
• Reflection helpers expect compatible types, members, and indexers.
• File helpers catch IOException but do not suppress every possible file-system exception.
• Connectivity checks suppress request failures and return False after all endpoints fail.

Threading and performance

• Helper classes contain shared methods and do not require instances.
• InternetHelper reuses one shared HttpClient.
• InternetHelper.IsInternetAvailable performs blocking network I/O.
• InternetHelper.IsInternetAvailableAsync should be preferred in asynchronous and UI applications.
• ReflectionHelper.GetRunTimeType emits a new in-memory dynamic assembly and type on every call; cache the returned type when it will be reused.
• DatabaseHelper.DebugQuery is intended only for development diagnostics.

Typical use cases

• Validating CPF or CNPJ values entered in a business application.
• Applying display masks to Brazilian contact and address data.
• Converting API timestamps to Brasília date/time.
• Populating user interfaces with enum values and descriptions.
• Inspecting a generated database command during development.
• Checking whether a temporary file can be deleted.
• Performing a lightweight online/offline check.
• Generating human-readable reference codes.
• Accessing non-public inherited methods in infrastructure code.
• Building temporary data shapes dynamically at runtime.

Project information

• Project: Helpers
• Assembly: CoreSuite.Helpers
• Namespace: CoreSuite.Helpers
• Framework: .NET 8
• External dependencies: None
• Repository: Part of the CoreSuite solution

License

See the license distributed with the CoreSuite repository for the terms that apply to this project.

CoreSuite.Helpers is designed to reduce repeated utility code while keeping common operations small, discoverable, and reusable across the CoreSuite ecosystem.