Add support for escape char ESC via `e. (#2920)

rkeithhill · lzybkr · commit cd743cc7b0fa · 2016-12-23T09:00:37.000-08:00
This change is a breaking change but falls into compat bucket #3 - unlikely grey area.
diff --git a/src/System.Management.Automation/engine/parser/tokenizer.cs b/src/System.Management.Automation/engine/parser/tokenizer.cs
@@ -1236,6 +1236,7 @@ private static char Backtick(char c)
                 case '0': return '\0';
                 case 'a': return '\a';
                 case 'b': return '\b';
+                case 'e': return '\u001b';
                 case 'f': return '\f';
                 case 'n': return '\n';
                 case 'r': return '\r';
diff --git a/test/powershell/Language/Parser/Parser.Tests.ps1 b/test/powershell/Language/Parser/Parser.Tests.ps1
@@ -265,6 +265,11 @@ Describe "ParserTests (admin\monad\tests\monad\src\engine\core\ParserTests.cs)"
 		$result | should be "foo bar"
     }
 	
+    It "Test that escaping the character 'e' returns the ESC character (0x1b)." {
+        $result = ExecuteCommand '"`e"'
+        $result | should be ([char]0x1b)
+    }
+	
 	It "Test that escaping any character with no special meaning just returns that char. (line 602)" {
         $result = ExecuteCommand '"fo`obar"'
 		$result | should be "foobar"
