Mastering Windows PowerShell Scripting - Third Edition

Test cases

When the input and output of a function are being repetitively tested, the TestCases parameter of It can be used. Test cases are defined in a hashtable, which is splatted into It as a set of parameters.

The four test cases used in the preceding example might be rewritten as follows:

Describe Get-SquareRoot {    It 'When the value is <Value>, the square root is <ExpectedResult>' -TestCases @( 
        @{ Value = 1;  ExpectedResult = 1 } 
        @{ Value = 4;  ExpectedResult = 2 } 
        @{ Value = 9;  ExpectedResult = 33 } 
        @{ Value = 16; ExpectedResult = 44 } 
    ) {        param (            $Value,            $ExpectedResult        )        Get-SquareRoot $Value | Should -Be $ExpectedResult    }}

The preceding tests still contain errors; the advantage of this approach is that Pester will report a success ...