Exclude duplicate files for Run.Path and CodeCoverage.Path (#2535)

* Return only unique files in Find-File

* Remove redundant loop in New-PesterContainer

* Refactor Get-CodeCoverageFilePaths and remove duplicates

* Improve perf in New-PesterContainer

src/Pester.RSpec.ps1

@@ -8,9 +8,7 @@
         [string] $Extension
     )
 
-
-    $files =
-    foreach ($p in $Path) {
+    $files = foreach ($p in $Path) {
         if ([String]::IsNullOrWhiteSpace($p)) {
             continue
         }
@@ -66,11 +64,13 @@
         }
     }
 
-    Filter-Excluded -Files $files -ExcludePath $ExcludePath | & $SafeCommands['Where-Object'] { $_ }
+    # Deduplicate files if overlapping -Path values
+    $uniquePaths = [System.Collections.Generic.HashSet[string]]::new(@($files).Count)
+    $uniqueFiles = foreach ($f in $files) { if ($uniquePaths.Add($f.FullName)) { $f } }
+    Filter-Excluded -Files $uniqueFiles -ExcludePath $ExcludePath | & $SafeCommands['Where-Object'] { $_ }
 }
 
 function Filter-Excluded ($Files, $ExcludePath) {
-
     if ($null -eq $ExcludePath -or @($ExcludePath).Length -eq 0) {
         return @($Files)
     }
@@ -81,12 +81,9 @@ function Filter-Excluded ($Files, $ExcludePath) {
         $excluded = $false
 
         foreach ($exclusion in (@($ExcludePath) -replace "/", "\")) {
-            if ($excluded) {
-                continue
-            }
-
             if ($p -like $exclusion) {
                 $excluded = $true
+                continue
             }
         }
 
@@ -571,15 +568,13 @@ function New-PesterContainer {
     }
 
     if ("Path" -eq $kind) {
-        # the @() is significant here, it will make it iterate even if there are no data
-        # which allows files without data to run
-        foreach ($d in @($dt)) {
-            foreach ($p in $Path) {
-                # resolve the path we are given in the same way we would resolve -Path on Invoke-Pester
-                $files = @(Find-File -Path $p -ExcludePath $PesterPreference.Run.ExcludePath.Value -Extension $PesterPreference.Run.TestExtension.Value)
-                foreach ($file in $files) {
-                    New-BlockContainerObject -File $file -Data $d
-                }
+        # resolve the path we are given in the same way we would resolve -Path on Invoke-Pester
+        $files = @(Find-File -Path $Path -ExcludePath $PesterPreference.Run.ExcludePath.Value -Extension $PesterPreference.Run.TestExtension.Value)
+        foreach ($file in $files) {
+            # the @() is significant here, it will make it iterate even if there are no data
+            # which allows files without data to run
+            foreach ($d in @($dt)) {
+                New-BlockContainerObject -File $file -Data $d
             }
         }
     }

src/functions/Coverage.ps1

@@ -211,54 +211,35 @@ function Resolve-CoverageInfo {
 
     $filePaths = Get-CodeCoverageFilePaths -Paths $resolvedPaths -IncludeTests $includeTests -RecursePaths $recursePaths
 
-    $params = @{
+    $commonParams = @{
         StartLine = $UnresolvedCoverageInfo.StartLine
         EndLine   = $UnresolvedCoverageInfo.EndLine
         Class     = $UnresolvedCoverageInfo.Class
         Function  = $UnresolvedCoverageInfo.Function
     }
 
     foreach ($filePath in $filePaths) {
-        $params['Path'] = $filePath
-        New-CoverageInfo @params
+        New-CoverageInfo @commonParams -Path $filePath
     }
 }
 
 function Get-CodeCoverageFilePaths {
     param (
-        [object]$Paths,
+        [string[]]$Paths,
         [bool]$IncludeTests,
         [bool]$RecursePaths
     )
 
     $testsPattern = "*$($PesterPreference.Run.TestExtension.Value)"
 
-    $filePaths = foreach ($path in $Paths) {
-        $item = & $SafeCommands['Get-Item'] -LiteralPath $path
-        if ($item -is [System.IO.FileInfo] -and ('.ps1', '.psm1') -contains $item.Extension -and ($IncludeTests -or $item.Name -notlike $testsPattern)) {
-            $item.FullName
-        }
-        elseif ($item -is [System.IO.DirectoryInfo]) {
-            $children = foreach ($i in & $SafeCommands['Get-ChildItem'] -LiteralPath $item) {
-                # if we recurse paths return both directories and files so they can be resolved in the
-                # recursive call to Get-CodeCoverageFilePaths, otherwise return just files
-                if ($RecursePaths) {
-                    $i.PSPath
-                }
-                elseif (-not $i.PSIsContainer) {
-                    $i.PSPath
-                }
-            }
-            Get-CodeCoverageFilePaths -Paths $children -IncludeTests $IncludeTests -RecursePaths $RecursePaths
-        }
-        elseif (-not $item.PsIsContainer) {
-            # todo: enable this warning for non wildcarded paths? otherwise it prints a ton of warnings for documentation and so on when using "folder/*" wildcard
-            # & $SafeCommands['Write-Warning'] "CodeCoverage path '$path' resolved to a non-PowerShell file '$($item.FullName)'; this path will not be part of the coverage report."
+    [string[]] $filteredFiles = @(foreach ($file in (& $SafeCommands['Get-ChildItem'] -LiteralPath $Paths -File -Recurse:$RecursePaths)) {
+        if (('.ps1', '.psm1') -contains $file.Extension -and ($IncludeTests -or $file.Name -notlike $testsPattern)) {
+            $file.FullName
         }
-    }
-
-    return $filePaths
+    })
 
+    $uniqueFiles = [System.Collections.Generic.HashSet[string]]::new($filteredFiles)
+    return $uniqueFiles
 }
 
 function Get-CoverageBreakpoints {

tst/Pester.Tests.ps1

@@ -244,6 +244,11 @@ InPesterModuleScope {
             ($paths -contains (Join-Path $testDrive "SomeOtherFile.Tests.ps1")) | Should -Be $true
         }
 
+        It 'Deduplicates filepaths when the provided paths overlaps' {
+            $result = @(Find-File 'TestDrive:\*.ps1','TestDrive:\*.ps1' -Extension '.Tests.ps1')
+            $result.Count | Should -Be 2
+        }
+
         # It 'Assigns empty array and hashtable to the Arguments and Parameters properties when none are specified by the caller' {
         #     $result = @(Find-File 'TestDrive:\SomeFile.ps1' -Extension ".Tests.ps1")