Do not append template if parameter description exists (#783)

Author: adityapatwardhan

src/Common/MergeUtils.cs

@@ -246,12 +246,15 @@ internal static bool TryGetMergedParameters(List<Parameter>fromHelp, List<Parame
 
                     var description = helpParam.Description;
 
+                    var templateDescription = string.Format(Constants.FillInParameterDescriptionTemplate, helpParam.Name);
+
                     if (string.Equals(helpParam.Description, checkTemplate, StringComparison.OrdinalIgnoreCase))
                     {
                         diagnosticMessages.Add(new DiagnosticMessage(DiagnosticMessageSource.Merge, $"Parameter {pName} has no description in the help.", DiagnosticSeverity.Warning, "TryGetMergedParameters", -1));
                         description = cmdParam.Description;
                     }
-                    else if (!string.Equals(helpParam.Description, cmdParam.Description, StringComparison.OrdinalIgnoreCase))
+                    else if (!string.Equals(cmdParam.Description, templateDescription, StringComparison.OrdinalIgnoreCase)
+                     && !string.Equals(helpParam.Description, cmdParam.Description, StringComparison.OrdinalIgnoreCase))
                     {
                         diagnosticMessages.Add(new DiagnosticMessage(DiagnosticMessageSource.Merge, $"Parameter {pName} has the different description in the help and the command. Concatinating.", DiagnosticSeverity.Information, "TryGetMergedParameters", -1));
                         description = string.Join(Environment.NewLine, helpParam.Description, cmdParam.Description);

test/Pester/MeasurePlatyPSMarkdown.Tests.ps1

@@ -13,9 +13,9 @@ Describe "Export-MarkdownModuleFile" {
 
     It "Should identify all the '<fileType>' assets" -TestCases @(
         @{ fileType = "unknown"; expectedCount = 2 }
-        @{ fileType = "CommandHelp"; expectedCount = 41 }
+        @{ fileType = "CommandHelp"; expectedCount = 42 }
         @{ fileType = "ModuleFile"; expectedCount = 16 }
-        @{ fileType = "V1Schema"; expectedCount = 52 }
+        @{ fileType = "V1Schema"; expectedCount = 53 }
         @{ fileType = "V2Schema"; expectedCount = 5 }
     ) {
         param ($fileType, $expectedCount)

test/Pester/UpdateCommandHelp.Tests.ps1

@@ -89,6 +89,11 @@ Describe "Tests for Update-CommandHelp" {
         $ch.AliasHeaderFound | Should -Be $true
     }
 
+    It "Should not append parameter descriptions with boiler plate if description is not boilerplate" {
+        $ch = Update-CommandHelp -Path ([io.path]::Combine($PSScriptRoot, "assets", "Export-Csv.md"))
+        $ch.Parameters.Where({$_.Name -eq "LiteralPath"}).Description | Should -Not -BeLike "*{{ Fill LiteralPath Description }}*"
+    }
+
     Context "Parameter attribute updates" {
         BeforeAll {
                 function test-update {