Adds emphasis to Select-String default formatter (PowerShell#8963)

Author: derek-xia

src/Microsoft.PowerShell.Commands.Utility/commands/utility/MatchString.cs

@@ -256,7 +256,7 @@ public string ToString(string directory)
         }
 
         /// <summary>
-        /// Returns the string representation of the match object with the matched line passed
+        /// Returns the string representation of the match object with the matched line passed 
         /// in as <paramref name="line"/> and trims the path to be relative to
         /// the<paramref name="directory"/> argument.
         /// </summary>
@@ -315,10 +315,10 @@ public string ToEmphasizedString(string directory)
         /// <returns>The matched line with matched text inverted.</returns>
         private string EmphasizeLine()
         {
-            string invertColorsVT100 = VTUtility.GetEscapeSequence(VTUtility.VT.Inverse);
-            string resetVT100 = VTUtility.GetEscapeSequence(VTUtility.VT.Reset);
+            const string InvertColorsVT100 = "\u001b[7m";
+            const string ResetVT100 = "\u001b[0m";
 
-            char[] chars = new char[(_matchIndexes.Count * (invertColorsVT100.Length + resetVT100.Length)) + Line.Length];
+            char[] chars = new char[(_matchIndexes.Count * (InvertColorsVT100.Length + ResetVT100.Length)) + Line.Length];
             int lineIndex = 0;
             int charsIndex = 0;
             for (int i = 0; i < _matchIndexes.Count; i++)
@@ -329,17 +329,17 @@ private string EmphasizeLine()
                 lineIndex = _matchIndexes[i];
 
                 // Adds opening vt sequence
-                invertColorsVT100.CopyTo(0, chars, charsIndex, invertColorsVT100.Length);
-                charsIndex += invertColorsVT100.Length;
+                InvertColorsVT100.CopyTo(0, chars, charsIndex, InvertColorsVT100.Length);
+                charsIndex += InvertColorsVT100.Length;
 
                 // Adds characters being emphasized
                 Line.CopyTo(lineIndex, chars, charsIndex, _matchLengths[i]);
                 lineIndex += _matchLengths[i];
                 charsIndex += _matchLengths[i];
 
                 // Adds closing vt sequence
-                resetVT100.CopyTo(0, chars, charsIndex, resetVT100.Length);
-                charsIndex += resetVT100.Length;
+                ResetVT100.CopyTo(0, chars, charsIndex, ResetVT100.Length);
+                charsIndex += ResetVT100.Length;
             }
 
             // Adds remaining characters in line

test/powershell/Modules/Microsoft.PowerShell.Utility/Select-String.Tests.ps1

@@ -7,10 +7,6 @@ Describe "Select-String" -Tags "CI" {
         $currentDirectory = $pwd.Path
     }
 
-    AfterAll {
-        Push-Location $currentDirectory
-    }
-
     Context "String actions" {
         $testinputone = "hello","Hello","goodbye"
         $testinputtwo = "hello","Hello"
@@ -80,47 +76,47 @@ Describe "Select-String" -Tags "CI" {
         }
 
         it "Should output a string with the first match highlighted" {
-            if ($Host.UI.SupportsVirtualTerminal -and !(Test-Path env:__SuppressAnsiEscapeSequences))
+            if ($Host.UI.SupportsVirtualTerminal)
             {
                 $result = $testinputone | Select-String -Pattern "l" | Out-String
-                $result | Should -Be "${nl}he`e[7ml`e[0mlo${nl}He`e[7ml`e[0mlo${nl}${nl}"
+                $result | Should -Be "`nhe`e[7ml`e[0mlo`nHe`e[7ml`e[0mlo`n`n"
             }
             else
             {
                 $result = $testinputone | Select-String -Pattern "l" | Out-String
-                $result | Should -Be "${nl}hello${nl}Hello${nl}${nl}"
+                $result | Should -Be "`nhello`nHello`n`n"
             }
         }
 
         it "Should output a string with all matches highlighted when AllMatch is used" {
-            if ($Host.UI.SupportsVirtualTerminal -and !(Test-Path env:__SuppressAnsiEscapeSequences))
+            if ($Host.UI.SupportsVirtualTerminal)
             {
                 $result = $testinputone | Select-String -Pattern "l" -AllMatch | Out-String
-                $result | Should -Be "${nl}he`e[7ml`e[0m`e[7ml`e[0mo${nl}He`e[7ml`e[0m`e[7ml`e[0mo${nl}${nl}"
+                $result | Should -Be "`nhe`e[7ml`e[0m`e[7ml`e[0mo`nHe`e[7ml`e[0m`e[7ml`e[0mo`n`n"
             }
             else
             {
                 $result = $testinputone | Select-String -Pattern "l" -AllMatch | Out-String
-                $result | Should -Be "${nl}hello${nl}Hello${nl}${nl}"
+                $result | Should -Be "`nhello`nHello`n`n"
             }
         }
 
         it "Should output a string with the first match highlighted when SimpleMatch is used" {
-            if ($Host.UI.SupportsVirtualTerminal -and !(Test-Path env:__SuppressAnsiEscapeSequences))
+            if ($Host.UI.SupportsVirtualTerminal)
             {
                 $result = $testinputone | Select-String -Pattern "l" -SimpleMatch | Out-String
-                $result | Should -Be "${nl}he`e[7ml`e[0mlo${nl}He`e[7ml`e[0mlo${nl}${nl}"
+                $result | Should -Be "`nhe`e[7ml`e[0mlo`nHe`e[7ml`e[0mlo`n`n"
             }
             else
             {
                 $result = $testinputone | Select-String -Pattern "l" -SimpleMatch | Out-String
-                $result | Should -Be "${nl}hello${nl}Hello${nl}${nl}"
+                $result | Should -Be "`nhello`nHello`n`n"
             }
         }
 
         it "Should output a string without highlighting when NoEmphasis is used" {
             $result = $testinputone | Select-String -Pattern "l" -NoEmphasis | Out-String
-            $result | Should -Be "${nl}hello${nl}Hello${nl}${nl}"
+            $result | Should -Be "`nhello`nHello`n`n"
         }
 
         it "Should return an array of matching strings without virtual terminal sequences" {
@@ -251,4 +247,8 @@ Describe "Select-String" -Tags "CI" {
             Select-String second $testInputFile -Raw -Context 2,2 | Should -BeExactly $expected
         }
     }
+
+    AfterAll {
+        Push-Location $currentDirectory
+    }
 }