MustContain for immutable array

[feO2x]

Closes #119

This pull request introduces a new MustContain assertion for ImmutableArray<T> to avoid boxing and improve performance when working with immutable arrays in the Light.GuardClauses library. It includes updates to both production code and corresponding unit tests, as well as documentation for the new feature. The most important changes are summarized below.

New Feature Implementation:

• Production Code: Added two MustContain extension methods for ImmutableArray<T> in Check.MustContain.cs. The first overload supports optional parameterName and message arguments and throws a MissingItemException when the item is not found. The second overload allows users to specify a custom exception using a delegate.

Unit Tests:

• Tests for MustContain: Added comprehensive unit tests for the new MustContain assertion in MustContainTests.cs. These tests cover scenarios such as the item being present or absent in the array, handling empty arrays, custom exceptions, and custom messages.

Documentation:

• Issue Documentation: Added a new markdown file issue-119-must-contain-for-immutable-array.md detailing the context, tasks, and notes for implementing the MustContain assertion for ImmutableArray<T>. This serves as a guide for contributors and users of the library.

Dependency Updates:

• Namespace Addition: Updated Check.MustContain.cs and MustContainTests.cs to include the System.Collections.Immutable namespace, enabling the use of ImmutableArray<T>. [1] [2]

[Copilot]

Pull Request Overview

This pull request introduces a new MustContain assertion for ImmutableArray<T> to avoid boxing and improve performance when working with immutable arrays in the Light.GuardClauses library.

• Adds two MustContain extension method overloads for ImmutableArray<T> with support for both default and custom exception handling
• Includes comprehensive unit tests covering various scenarios including empty arrays, custom exceptions, and custom messages
• Provides documentation detailing the implementation requirements and context for the new feature

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
issue-119-must-contain-for-immutable-array.md	Documentation outlining implementation tasks and requirements for the new feature
Check.MustContain.cs	Adds two MustContain extension methods for ImmutableArray<T> with default and custom exception support
MustContainTests.cs	Comprehensive unit tests for the new MustContain methods covering edge cases and validation scenarios