Fix adapting Regex for C# (#172)

* add failing adaptable regex test * fix adapting regex
sebastienros · Jul 11, 2021 · 029c0f8 · 029c0f8
1 parent d9dabfa
commit 029c0f8
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Showing 2 changed files with 32 additions and 11 deletions.
diff --git a/src/Esprima/Scanner.cs b/src/Esprima/Scanner.cs
@@ -1574,22 +1574,31 @@ public Token ScanTemplate()
             try
             {
                 // Do we need to convert the expression to its .NET equivalent?
-                if (_adaptRegexp && options.HasFlag(RegexOptions.Multiline))
+                if (_adaptRegexp)
                 {
-                    // Replace all non-escaped $ occurences by \r?$
-                    // c.f. http://programmaticallyspeaking.com/regular-expression-multiline-mode-whats-a-newline.html
-
-                    int index = 0;
                     var newPattern = pattern;
-                    while ((index = newPattern.IndexOf("$", index, StringComparison.Ordinal)) != -1)
+
+                    if (options.HasFlag(RegexOptions.Multiline))
                     {
-                        if (index > 0 && newPattern[index - 1] != '\\')
+                        // Replace all non-escaped $ occurences by \r?$
+                        // c.f. http://programmaticallyspeaking.com/regular-expression-multiline-mode-whats-a-newline.html
+
+                        int index = 0;
+                        while ((index = newPattern.IndexOf("$", index, StringComparison.Ordinal)) != -1)
                         {
-                            newPattern = newPattern.Substring(0, index) + @"\r?" + newPattern.Substring(index);
-                            index += 4;
+                            if (index > 0 && newPattern[index - 1] != '\\')
+                            {
+                                newPattern = newPattern.Substring(0, index) + @"\r?" + newPattern.Substring(index);
+                                index += 4;
+                            }
                         }
                     }
 
+                    if (newPattern.Contains("[^]"))
+                    {
+                        newPattern = newPattern.Replace("[^]", "[^.]");
+                    }
+
                     pattern = newPattern;
                 }
 

diff --git a/test/Esprima.Tests/RegExpTests.cs b/test/Esprima.Tests/RegExpTests.cs
@@ -20,8 +20,8 @@ private static Regex CreateRegex(string code)
             };
             var token = new Scanner(code, options).ScanRegExp();
             return (Regex) token.Value;
-        }
-
+        }
+
         [Theory]
         [InlineData(@"/[^]*? (:[rp] [el] a[\w -]+)[^]*/")]
         [InlineData(@"/[^]/")]
@@ -32,6 +32,18 @@ public void ShouldParseRegularExpression(string regexp)
             var program = parser.ParseScript();
 
             Assert.NotNull(program);
+        }
+
+        [Theory]
+        [InlineData(@"/[^]*? (:[rp] [el] a[\w -]+)[^]*/")]
+        [InlineData(@"/[^]/")]
+        [InlineData(@"/[^ ]/")]
+        public void ShouldGetNonNullRegexFromScanner(string regexp)
+        {
+            var scanner = new Scanner("", new ParserOptions { AdaptRegexp = true });
+            var regex = scanner.TestRegExp(regexp, "");
+
+            Assert.NotNull(regex);
         }
     }
 }