PowerShell cmdlet ready to be unit tested

using System;
using System.Management.Automation;
using System.Collections.Generic;
// ReSharper disable UnusedAutoPropertyAccessor.Global - for PowerShell purposes
// ReSharper disable MemberCanBePrivate.Global - for PowerShell purposes

namespace CoreView.Management.PowerShell.Commands {
    [Cmdlet(VerbsLifecycle.Invoke, "CVApi")]
    public class InvokeCVApiCommand : PSCmdlet {
        [Parameter(Mandatory = false, HelpMessage = "Output folder. If empty, cmdlet folder will be used")]
        public string OutputFolder { get; set; }

        [Parameter(Mandatory = true, HelpMessage = "JSON file containing functions with parameters.", ParameterSetName = "FileToProcess")]
        public string FunctionFilePath { get; set; }

        private readonly ISimpleLogger _logger;
        private readonly IInvocationFileManager _fileManager;
        private readonly ApiInvoker _apiInvoker;
        private readonly IParameterParser<InvokeCvApiInputParameters, InvokeCvApiParsedParameters> _parameterParser;
        private readonly IContextProvider _contextProvider;

        // ReSharper disable once UnusedMember.Global - used automatically
        public InvokeCVApiCommand() {
            _logger = new SimpleLogger(new CmdletLogger(this));
            var fileInteractor = new FileInteractor();
            _fileManager = new InvocationFileManager(_logger, fileInteractor);
            _parameterParser = new InvokeCvApiParameterParser(fileInteractor, _fileManager, _logger);
            _apiInvoker = new ApiInvoker(_logger);
        }

        public InvokeCVApiCommand(IContextProvider contextProvider,
            IInvocationFileManager fileManager,
            ISimpleLogger logger,
            IParameterParser<InvokeCvApiInputParameters, InvokeCvApiParsedParameters> parser) {
            _fileManager = fileManager;
            _logger = logger;
            _parameterParser = parser;
            _apiInvoker = new ApiInvoker(_logger);
            _contextProvider = contextProvider;
        }

        protected override void ProcessRecord() {
            Environment.CurrentDirectory = _contextProvider.GetCurrentDirectory(this);
            base.ProcessRecord();
            var commandParams = new InvokeCvApiInputParameters(
                OutputFolder,
                FunctionFilePath,
                _contextProvider.GetCurrentDirectory(this));

            try {
                var parsedParameters = _parameterParser.Parse(commandParams);
                var invocationResults = InvokeAllApiMethods(parsedParameters);
                _fileManager.WriteLogToFile(_logger, parsedParameters.LogFilePath);
                WriteObject(invocationResults);
            } catch (Exception ex) {
                _logger.Exception("Unexpected exception occurred. Program terminates.", ex);
            }
        }

        internal void ProcessInternal() {
            BeginProcessing();
            ProcessRecord();
            EndProcessing();
        }


        private List<Tuple<FunctionInvocationData, FunctionInvocationResult>> InvokeAllApiMethods(InvokeCvApiParsedParameters parsedParameters) {
            var invocationResults = new List<Tuple<FunctionInvocationData, FunctionInvocationResult>>();
            foreach (var invocationData in parsedParameters.AllRequiredInvocations)
            {
                var invocationResult = _apiInvoker.InvokeApiCommand(invocationData, parsedParameters,
                    _contextProvider.GetLegacyContext());
                invocationResults.Add(new Tuple<FunctionInvocationData, FunctionInvocationResult>(invocationData, invocationResult));
            }

            _logger.Info($"All {parsedParameters.AllRequiredInvocations.Count} invocations completed.");

            return invocationResults;
        }
    }
}