.modules/Pester/3.4.2/en-US/about_Should.help.txt
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about_Should SHORT DESCRIPTION Provides assertion convenience methods for comparing objects and throwing test failures when test expectations fail. LONG DESCRIPTION Should is an Extension of System.Object and can be used as a native type inside Describe blocks. The various Should member methods can be invoked directly from an object being compared. It is typically used in individual It blocks to verify the results of an expectation. The Should method is typically called from the "actual" object being compared and takes the expected" object as a parameter. Should includes several members that perform various comparisons of objects and will throw a PesterFailure when the objects do not evaluate to be comparable. SHOULD MEMBERS Be Compares one object with another for equality and throws if the two objects are not the same. $actual="Actual value" $actual | Should Be "actual value" # Test will pass $actual | Should Be "not actual value" # Test will fail BeExactly Compares one object with another for equality and throws if the two objects are not the same. This comparison is case sensitive. $actual="Actual value" $actual | Should BeExactly "Actual value" # Test will pass $actual | Should BeExactly "actual value" # Test will fail BeGreaterThan Asserts that a number is greater than an expected value. Uses PowerShell's -gt operator to compare the two values. $Error.Count | Should BeGreaterThan 0 BeLessThan Asserts that a number is less than an expected value. Uses PowerShell's -gt operator to compare the two values. $Error.Count | Should BeLessThan 1 BeLike Asserts that the actual value matches a wildcard pattern using PowerShell's -like operator. This comparison is not case-sensitive. $actual="Actual value" $actual | Should BeLike "actual *" # Test will pass $actual | Should BeLike "not actual *" # Test will fail BeLikeExactly Asserts that the actual value matches a wildcard pattern using PowerShell's -like operator. This comparison is case-sensitive. $actual="Actual value" $actual | Should BeLikeExactly "Actual *" # Test will pass $actual | Should BeLikeExactly "actual *" # Test will fail BeOfType Asserts that the actual value should be an object of a specified type (or a subclass of the specified type) using PowerShell's -is operator: $actual = Get-Item $env:SystemRoot $actual | Should BeOfType System.IO.DirectoryInfo # Test will pass; object is a DirectoryInfo $actual | Should BeOfType System.IO.FileSystemInfo # Test will pass; DirectoryInfo base class is FileSystemInfo $actual | Should BeOfType System.IO.FileInfo # Test will fail; FileInfo is not a base class of DirectoryInfo BeNullOrEmpty Checks values for null or empty (strings). The static [String]::IsNullOrEmpty() method is used to do the comparison. $null | Should BeNullOrEmpty # Test will pass $null | Should Not BeNullOrEmpty # Test will fail @() | Should BeNullOrEmpty # Test will pass "" | Should BeNullOrEmpty # Test will pass Exist Does not perform any comparison but checks if the object calling Exist is present in a PS Provider. The object must have valid path syntax. It essentially must pass a Test-Path call. $actual=(Dir . )[0].FullName Remove-Item $actual $actual | Should Exist # Test will fail Contain Checks to see if a file contains the specified text. This search is not case sensitive and uses regular expressions. Set-Content -Path TestDrive:\file.txt -Value 'I am a file.' 'TestDrive:\file.txt' | Should Contain 'I Am' # Test will pass 'TestDrive:\file.txt' | Should Contain '^I.*file$' # Test will pass 'TestDrive:\file.txt' | Should Contain 'I Am Not' # Test will fail Tip: Use [regex]::Escape("pattern") to match the exact text. Set-Content -Path TestDrive:\file.txt -Value 'I am a file.' 'TestDrive:\file.txt' | Should Contain 'I.am.a.file' # Test will pass 'TestDrive:\file.txt' | Should Contain ([regex]::Escape('I.am.a.file')) # Test will fail ContainExactly Checks to see if a file contains the specified text. This search is case sensitive and uses regular expressions to match the text. Set-Content -Path TestDrive:\file.txt -Value 'I am a file.' 'TestDrive:\file.txt' | Should Contain 'I am' # Test will pass 'TestDrive:\file.txt' | Should Contain 'I Am' # Test will fail Match Uses a regular expression to compare two objects. This comparison is not case sensitive. "I am a value" | Should Match "I Am" # Test will pass "I am a value" | Should Match "I am a bad person" # Test will fail Tip: Use [regex]::Escape("pattern") to match the exact text. "Greg" | Should Match ".reg" # Test will pass "Greg" | Should Match ([regex]::Escape(".reg")) # Test will fail MatchExactly Uses a regular expression to compare two objects. This comparison is case sensitive. "I am a value" | Should MatchExactly "I am" # Test will pass "I am a value" | Should MatchExactly "I Am" # Test will fail Throw Checks if an exception was thrown. Enclose input in a script block. { foo } | Should Throw # Test will pass { $foo = 1 } | Should Throw # Test will fail { foo } | Should Not Throw # Test will fail { $foo = 1 } | Should Not Throw # Test will pass Warning: The input object must be a ScriptBlock, otherwise it is processed outside of the assertion. Get-Process -Name "process" -ErrorAction Stop | Should Throw # Should pass, but the exception thrown by Get-Process causes the test to fail. NEGATIVE ASSERTIONS Any of the Should operators described above can be negated by using the word "Not" before the operator. For example: 'one' | Should Not Be 'Two' { Get-Item $env:SystemRoot } | Should Not Throw USING SHOULD IN A TEST function Add-Numbers($a, $b) { return $a + $b } Describe "Add-Numbers" { It "adds positive numbers" { $sum = Add-Numbers 2 3 $sum | Should Be 3 } } This test will fail since 3 will not be equal to the sum of 2 and 3. SEE ALSO Describe Context It |