GetList.cs

using System.Management.Automation;
using Microsoft.SharePoint.Client;
using PnP.PowerShell.CmdletHelpAttributes;
using PnP.PowerShell.Commands.Base.PipeBinds;
using System.Linq.Expressions;
using System;
using Resources = PnP.PowerShell.Commands.Properties.Resources;

namespace PnP.PowerShell.Commands.Lists
{
    [Cmdlet(VerbsCommon.Get, "PnPList")]
    [CmdletHelp("Returns lists from SharePoint",
        Category = CmdletHelpCategory.Lists,
        OutputType = typeof(List),
        OutputTypeLink = "https://docs.microsoft.com/previous-versions/office/sharepoint-server/ee540626(v=office.15)")]
    [CmdletExample(
        Code = "PS:> Get-PnPList",
        Remarks = "Returns all lists in the current web",
        SortOrder = 1)]
    [CmdletExample(
        Code = "PS:> Get-PnPList -Identity 99a00f6e-fb81-4dc7-8eac-e09c6f9132fe",
        Remarks = "Returns a list with the given id",
        SortOrder = 2)]
    [CmdletExample(
        Code = "PS:> Get-PnPList -Identity Lists/Announcements",
        Remarks = "Returns a list with the given url",
        SortOrder = 3)]
    [CmdletExample(
        Code = @"PS:> Get-PnPList | Where-Object {$_.RootFolder.ServerRelativeUrl -like ""/lists/*""}",
        Remarks = @"This examples shows how to do wildcard searches on the list URL. It returns all lists whose URL starts with ""/lists/"" This could also be used to search for strings inside of the URL.",
        SortOrder = 4)]
    public class GetList : PnPWebRetrievalsCmdlet<List>
    {
        [Parameter(Mandatory = false, ValueFromPipeline = true, Position = 0, HelpMessage = "The ID, name or Url (Lists/MyList) of the list")]
        public ListPipeBind Identity;

        [Parameter(Mandatory = false, HelpMessage = "Switch parameter if an exception should be thrown if the requested list does not exist (true) or if omitted, nothing will be returned in case the list does not exist")]
        public SwitchParameter ThrowExceptionIfListNotFound;

        protected override void ExecuteCmdlet()
        {
            DefaultRetrievalExpressions = new Expression<Func<List, object>>[] { l => l.Id, l => l.BaseTemplate, l => l.OnQuickLaunch, l => l.DefaultViewUrl, l => l.Title, l => l.Hidden, l => l.RootFolder.ServerRelativeUrl };

            if (Identity != null)
            {
                var list = Identity.GetList(SelectedWeb);

                if (ThrowExceptionIfListNotFound && list == null)
                { 
                    throw new PSArgumentException(string.Format(Resources.ListNotFound, Identity), nameof(Identity));
                }
                list?.EnsureProperties(RetrievalExpressions);

                WriteObject(list);
            }
            else
            {
                var query = SelectedWeb.Lists.IncludeWithDefaultProperties(RetrievalExpressions);
                var lists = ClientContext.LoadQuery(query);
                ClientContext.ExecuteQueryRetry();
                WriteObject(lists, true);
            }
        }
    }
}