Sync eng/common directory with azure-sdk-tools for PR 1808 (#1828)

* Add FilterPoliCheckResult.ps1

* Add description to FilterPoliCheckResults.ps1

Co-authored-by: Chidozie Ononiwu <chononiw@microsoft.com>

eng/common/scripts/FilterPoliCheckResults.ps1

@@ -0,0 +1,103 @@
+<#
+.SYNOPSIS
+Filters PoliCheck Result.
+.DESCRIPTION
+This script will read data speciefied in one or more PoliCheckAllowList.yml files,
+It then reamoves all allwed entries from the PoliCheckResult 
+.PARAMETER PoliCheckResultFilePath
+The Path to the PoliCheck Result. Usually named PoliCheck.sarif
+.PARAMETER ServiceDirtectory
+If the PoliCheck scan is scoped to a particular service provide the ServiceDirectory
+.EXAMPLE
+PS> ./FilterPoliCheckResults.ps1 -PoliCheckResultFilePath .\PoliCheck.sarif
+#>
+[CmdletBinding()]
+param(
+  [Parameter(Mandatory=$true)]
+  [String] $PoliCheckResultFilePath,
+  [String] $ServiceDirtectory
+)
+
+. "${PSScriptRoot}\logging.ps1"
+
+$RepoRoot = Resolve-Path -Path "${PSScriptRoot}\..\..\..\"
+$PathToAllowListFiles = Join-Path $RepoRoot $ServiceDirtectory
+$PolicCheckAllowListFiles = Get-ChildItem -Path $PathToAllowListFiles -Recurse -File -Include "PoliCheckAllowList.yml"
+$allowListData = @{}
+
+# Combine all AllowLists Found
+foreach ($file in $PolicCheckAllowListFiles)
+{
+    $allowListDataInFile = ConvertFrom-Yaml (Get-Content $file.FullName -Raw)
+    $allowListData["PC1001"] += $allowListDataInFile["PC1001"]
+    $allowListData["PC1002"] += $allowListDataInFile["PC1002"]
+    $allowListData["PC1003"] += $allowListDataInFile["PC1003"]
+    $allowListData["PC1004"] += $allowListDataInFile["PC1004"]
+    $allowListData["PC1005"] += $allowListDataInFile["PC1005"]
+    $allowListData["PC1006"] += $allowListDataInFile["PC1006"]
+}
+
+$poliCheckData = Get-Content $PoliCheckResultFilePath | ConvertFrom-Json
+$poliCheckResultsCount = $poliCheckData.runs[0].results.Count
+$newCount
+
+$updatedRuns = @()
+
+foreach ($run in $poliCheckData.runs)
+{
+    $updatedResults = @()
+    foreach ($result in $run.results)
+    {
+        $ruleId = $result.ruleId
+        $allowedEntries = $allowListData[$ruleId]
+        if ($allowedEntries)
+        {
+            $updatedLocations = @()
+
+            foreach ($location in $result.locations)
+            {
+                $filePath = $location.physicalLocation.artifactLocation.uri
+                $text = $location.physicalLocation.region.snippet.text
+                $contextRegion = $location.physicalLocation.contextRegion.snippet.text
+
+                $allowedEntry = $allowedEntries[0] | Where-Object { $_.FilePath -eq $filePath }
+
+                if ($allowedEntry.Count -gt 0)
+                {
+                    $foundAllowedInstance = $false
+                    foreach ($instance in $allowedEntry.instances)
+                    {
+                        if (($instance.Text.Trim() -eq $text.Trim()) -and ($instance.ContextRegion.Trim() -eq $contextRegion.Trim()))
+                        {
+                            Write-Host "Found instance" -ForegroundColor Green
+                            $foundAllowedInstance = $true
+                        }
+                    }
+                    if ($foundAllowedInstance -eq $true)
+                    {
+                        continue
+                    }
+                }
+
+                $updatedLocations += $location
+            }
+
+            $result.locations = $updatedLocations
+        }
+
+        if ($result.locations.Count -gt 0)
+        {
+            $updatedResults += $result 
+        }
+    }
+    $run.results = $updatedResults
+    $newCount = $run.results.Count
+    $updatedRuns += $run
+}
+
+$poliCheckData.runs = $updatedRuns
+
+Set-Content -Path $PoliCheckResultFilePath -Value ($poliCheckData | ConvertTo-Json -Depth 100)
+
+LogDebug "Original Result Count: ${poliCheckResultsCount}"
+LogDebug "New Result Count: ${newCount}"