report invalid RegEx flags eagerly

sebastienros · May 28, 2019 · 715a6c9 · 715a6c9
1 parent dd5b4b9
commit 715a6c9
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Showing 2 changed files with 8 additions and 10 deletions.
diff --git a/src/Esprima/Scanner.cs b/src/Esprima/Scanner.cs
@@ -1474,17 +1474,8 @@ public Regex TestRegExp(string pattern, string flags)
                 tmp = Regex.Replace(tmp, "[\uD800-\uDBFF][\uDC00-\uDFFF]", astralSubstitute);
             }
 
-            RegexOptions options = RegexOptions.ECMAScript;
-
             // First, detect invalid regular expressions.
-            try
-            {
-                options = ParseRegexOptions(flags);
-            }
-            catch
-            {
-                return null;
-            }
+            var options = ParseRegexOptions(flags);
 
             try
             {

diff --git a/test/Esprima.Tests/ParserTests.cs b/test/Esprima.Tests/ParserTests.cs
@@ -173,5 +173,12 @@ public void CanParseDot(string script)
             var parser = new JavaScriptParser(script);
             Assert.Throws<ParserException>(() => parser.ParseProgram());
         }
+
+        [Fact]
+        public void ThrowsErrorForInvalidRegExFlags()
+        {
+            var parser = new JavaScriptParser("/'/o//'///C//ÿ");
+            Assert.Throws<ParserException>(() => parser.ParseProgram());
+        }
     }
 }