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The Assert class is a part of the Cobra Logging package, designed to facilitate assertions within applications. It provides a range of methods for validating conditions, enhancing code robustness by identifying issues early in the development process.


  • Comprehensive Validation: Supports various assertions including null checks, collection emptiness, numeric comparisons, and more.
  • Informative Logging: Logs detailed messages upon assertion failure, aiding in quick issue identification.
  • Exception Control: Optionally throws exceptions on failed assertions to halt execution, signaling critical issues immediately.

Key Methods

  • NotNull: Ensures a specified parameter is not null.
  • NotEmpty: Verifies a collection is not empty.
  • NotNullOrWhitespace: Confirms a string is neither null, empty, nor whitespace only.
  • GreaterThan: Checks if a value is greater than a specified limit.
  • LessThan: Verifies a value is less than a specified limit.
  • InRange: Asserts a value falls within a specified range.
  • NotNullOrEmpty: Ensures a collection is neither null nor empty.
  • AreEqual: Verifies the value of a parameter matches an expected value.
  • Contains: Asserts a collection contains an item that meets a specified condition.
  • DoesNotContain: Ensures a collection does not contain any item that satisfies a provided condition.
  • Implements: Checks if an object implements a specified interface.


Basic Assertions

Assert.NotNull(() => myObject, "MyObject must not be null.");
Assert.NotEmpty(() => myList, "The list cannot be empty.");
Assert.NotNullOrWhitespace(() => myString, "Input cannot be blank.");

Numeric Comparisons

Assert.GreaterThan(() => age, 18, "Age must be over 18.");
Assert.LessThan(() => temperature, 100, "Temperature must be below 100 degrees.");
Assert.InRange(() => score, 0, 100, "Score must be between 0 and 100.");

Collection Assertions

Assert.NotNullOrEmpty(() => myCollection, "The collection cannot be null or empty.");
Assert.Contains(() => myCollection, item => item.IsValid, "Collection must contain at least one valid item.");
Assert.DoesNotContain(() => myCollection, item => item.IsExpired, "Collection should not contain expired items.");

Type Assertions

Assert.Implements<IExpectedInterface>(() => myObject, "Object must implement IExpectedInterface.");

Advanced Features

  • ParameterExpression: Utilizes lambda expressions for parameter checks, enabling precise identification of the assertion's context.
  • Custom Messages: Allows specifying custom messages to enhance the information provided by logs on assertion failures.
  • Control Over Exceptions: The throwException parameter dictates whether an exception is thrown, offering flexibility based on the criticality of the assertion.