Handles + character in supported equality and function operators in filter expressions

[timayabi2020]



Fixes #2973

Changes proposed in this pull request

• This change handles scenarios where equality operator types like in and has contain + character enclosed within brackets in filter expressions.
• It also handles scenarios where function operator types like startsWith contain + characters).

[andrueastman]

Is it possible to capture these scenarios in a test to prevent a regression in the future?

[timayabi2020]

This will be tricky because the extension method a cmdlet derived from PSCmdlet class and cmdlets derived from the PSCmdlet class in PowerShell cannot be invoked directly because they are designed to be used within the context of a PowerShell runtime environment.

For example in a unit test we will need to have something like the code below calling a cmdlet implementation.

        var cmdlet = new CommandA();
        cmdlet.Value = "('Khalayi+mzuri')";
        cmdlet.Invoke();

The above won't work because we will not have a PowerShell run time which PSmdlet class depends on.

Below is the cmdlet implementation which we hope it can use the extension method.

using System.Management.Automation;

public class CommandA : PSCmdlet
{
    [Parameter(Position = 0, Mandatory = true)]
    public string Value { get; set; }

    protected override void ProcessRecord()
    {
       WriteObject(this.UnescapeString(Value));
    }
}

This is one of the limitations we currently having when it comes to writing unit testing some an extension method expecting a Cmdlet class.

For now we can only rely on manual tests after the cmldets have been generated. However, suggestions on how to go about this are much welcomed.