Add configuration.Debug.ShowStartMarkers support (fixes #2583). (#2612)

Allow displaying an indication when each test starts:
[|] Test name...

src/csharp/Pester/DebugConfiguration.cs

@@ -34,6 +34,7 @@ public static DebugConfiguration ShallowClone(DebugConfiguration configuration)
             WriteDebugMessages = new BoolOption("Write Debug messages to screen.", false);
             WriteDebugMessagesFrom = new StringArrayOption("Write Debug messages from a given source, WriteDebugMessages must be set to true for this to work. You can use like wildcards to get messages from multiple sources, as well as * to get everything.", new string[] { "Discovery", "Skip", "Mock", "CodeCoverage" });
             ShowNavigationMarkers = new BoolOption("Write paths after every block and test, for easy navigation in VSCode.", false);
+            ShowStartMarkers = new BoolOption("Write an indication when each test starts.", false);
             ReturnRawResultObject = new BoolOption("Returns unfiltered result object, this is for development only. Do not rely on this object for additional properties, non-public properties will be renamed without previous notice.", false);
         }
 
@@ -45,6 +46,7 @@ public DebugConfiguration(IDictionary configuration) : this()
                 configuration.AssignValueIfNotNull<bool>(nameof(WriteDebugMessages), v => WriteDebugMessages = v);
                 configuration.AssignArrayIfNotNull<string>(nameof(WriteDebugMessagesFrom), v => WriteDebugMessagesFrom = v);
                 configuration.AssignValueIfNotNull<bool>(nameof(ShowNavigationMarkers), v => ShowNavigationMarkers = v);
+                configuration.AssignValueIfNotNull<bool>(nameof(ShowStartMarkers), v => ShowStartMarkers = v);
                 configuration.AssignValueIfNotNull<bool>(nameof(ReturnRawResultObject), v => ReturnRawResultObject = v);
             }
         }
@@ -53,6 +55,7 @@ public DebugConfiguration(IDictionary configuration) : this()
         private BoolOption _writeDebugMessages;
         private StringArrayOption _writeDebugMessagesFrom;
         private BoolOption _showNavigationMarkers;
+        private BoolOption _showStartMarkers;
         private BoolOption _returnRawResultObject;
 
         public BoolOption ShowFullErrors
@@ -119,6 +122,22 @@ public BoolOption ShowNavigationMarkers
             }
         }
 
+        public BoolOption ShowStartMarkers
+        {
+            get { return _showStartMarkers; }
+            set
+            {
+                if (_showStartMarkers == null)
+                {
+                    _showStartMarkers = value;
+                }
+                else
+                {
+                    _showStartMarkers = new BoolOption(_showStartMarkers, value.Value);
+                }
+            }
+        }
+
         public BoolOption ReturnRawResultObject
         {
             get { return _returnRawResultObject; }

src/en-US/about_PesterConfiguration.help.txt

@@ -182,6 +182,10 @@ SECTIONS AND OPTIONS
         Type: bool
         Default value: $false
 
+        ShowStartMarkers: Write an indication when each test starts.
+        Type: bool
+        Default value: $false
+
         ReturnRawResultObject: Returns unfiltered result object, this is for development only. Do not rely on this object for additional properties, non-public properties will be renamed without previous notice.
         Type: bool
         Default value: $false

src/functions/Output.ps1

@@ -607,10 +607,20 @@ function Get-WriteScreenPlugin ($Verbosity) {
     if ($PesterPreference.Output.Verbosity.Value -in 'Detailed', 'Diagnostic') {
         $p.EachTestSetupStart = {
             param ($Context)
+
+            # we are currently in scope of describe so $Test is hardtyped and conflicts
+            $_test = $Context.Test
+
             # we postponed writing the Describe / Context to grab the Expanded name, because that is done
             # during execution to get all the variables in scope, if we are the first test then write it
-            if ($Context.Test.First) {
-                Write-BlockToScreen $Context.Test.Block
+            if ($_test.First) {
+                Write-BlockToScreen $_test.Block
+            }
+
+            if ($PesterPreference.Debug.ShowStartMarkers.Value) {
+                $level = $_test.Path.Count
+                $margin = $ReportStrings.Margin * ($level)
+                Write-PesterHostMessage -ForegroundColor $ReportTheme.Information "$margin[|] $($_test.ExpandedName)..."
             }
         }
     }

tst/Pester.RSpec.Configuration.ts.ps1

@@ -160,6 +160,10 @@ i -PassThru:$PassThru {
             [PesterConfiguration]::Default.Debug.ShowNavigationMarkers.Value | Verify-False
         }
 
+        t "Debug.ShowStartMarkers is `$false" {
+            [PesterConfiguration]::Default.Debug.ShowStartMarkers.Value | Verify-False
+        }
+
         t "TestDrive.Enabled is `$true" {
             [PesterConfiguration]::Default.TestDrive.Enabled.Value | Verify-True
         }

tst/Pester.RSpec.Output.ts.ps1

@@ -141,6 +141,49 @@ i -PassThru:$PassThru {
             @($describeFailing).Count | Verify-Equal 1
             @($contextFailing).Count | Verify-Equal 1
         }
+
+        t 'All start markers are output when ShowStartMarkers is enabled' {
+            $sb = {
+                $PesterPreference = [PesterConfiguration]::Default
+                $PesterPreference.Output.Verbosity = 'Detailed'
+                $PesterPreference.Debug.ShowStartMarkers = $true
+                $PesterPreference.Output.CIFormat = 'None'
+                $PesterPreference.Output.RenderMode = 'ConsoleColor'
+
+                $container = New-PesterContainer -ScriptBlock {
+                    Describe 'd1' {
+                        Context 'c1' {
+                            It 'i1' {
+                                1 | Should -Be 1
+                            }
+
+                            It 'i2' {
+                                1 | Should -Be 1
+                            }
+                        }
+
+                        Context 'c2' {
+                            It 'i3' {
+                                1 | Should -Be 1
+                            }
+                        }
+                    }
+                }
+                Invoke-Pester -Container $container
+            }
+
+            $output = Invoke-InNewProcess $sb
+            # only print the relevant part of output
+            $null, $run = $output -join "`n" -split 'Running tests.'
+            $run | Write-Host
+
+            $i1Start = $output | Select-String -Pattern '\[\|\] i1\.\.\.$'
+            @($i1Start).Count | Verify-Equal 1
+            $i2Start = $output | Select-String -Pattern '\[\|\] i2\.\.\.$'
+            @($i2Start).Count | Verify-Equal 1
+            $i3Start = $output | Select-String -Pattern '\[\|\] i3\.\.\.$'
+            @($i3Start).Count | Verify-Equal 1
+        }
     }
 
     b 'Output for data-driven blocks' {