Should Operators

Be Compares one object with another for equality Case Insensitive
BeExactly Compares one object with another for equality Case Sensitive
BeGreaterThan Asserts that a number is greater than an expected value  
BeLessThan Asserts that a number is less than an expected value  
BeLike Asserts that the actual value matches a wildcard pattern using -like operator Case Insensitive
BeLikeExactly Asserts that the actual value matches a wildcard pattern using -like operator Case Sensitive
BeOfType Asserts that the actual value be an object of a specified type  
Exist Does not perform any comparison but checks if the object calling Exist is present in a PS Provider  
Contain Checks to see if a file contains the specified text Case Insensitive
ContainExactly Checks to see if a file contains the specified text Case Sensitive
Match Uses a regular expression to compare two objects Case Insensitive
MatchExactly Uses a regular expression to compare two objects Case Sensitive
Throw Checks if an exception was thrown in the input ScriptBlock  
BeNullOrEmpty Checks values for null or empty (strings)