Add invalid regular expression literal error #3432

src/compiler/diagnosticInformationMap.generated.ts

@@ -616,5 +616,6 @@ namespace ts {
         JSX_attribute_expected: { code: 17003, category: DiagnosticCategory.Error, key: "JSX attribute expected." },
         Cannot_use_JSX_unless_the_jsx_flag_is_provided: { code: 17004, category: DiagnosticCategory.Error, key: "Cannot use JSX unless the '--jsx' flag is provided." },
         A_constructor_cannot_contain_a_super_call_when_its_class_extends_null: { code: 17005, category: DiagnosticCategory.Error, key: "A constructor cannot contain a 'super' call when its class extends 'null'" },
+        Invalid_regular_expression_literal: { code: 17006, category: DiagnosticCategory.Error, key: "Invalid regular expression literal." },
     };
 }

src/compiler/diagnosticMessages.json

@@ -2457,5 +2457,9 @@
     "A constructor cannot contain a 'super' call when its class extends 'null'": {
       "category": "Error",
       "code": 17005
+    },
+    "Invalid regular expression literal.": {
+      "category": "Error",
+      "code": 17006
     }
 }

src/compiler/scanner.ts

@@ -347,6 +347,15 @@ namespace ts {
 
     let hasOwnProperty = Object.prototype.hasOwnProperty;
 
+    function isValidRegex(r : string): boolean {
+        try {
+            RegExp(r);
+        } catch (e) {
+            return false;
+        }
+        return true;
+    }
+
     export function isWhiteSpace(ch: number): boolean {
         // Note: nextLine is in the Zs space, and should be considered to be a whitespace.
         // It is explicitly not a line-break as it isn't in the exact set specified by EcmaScript.
@@ -1536,6 +1545,11 @@ namespace ts {
                 }
                 pos = p;
                 tokenValue = text.substring(tokenPos, pos);
+
+                if (inCharacterClass || !isValidRegex(tokenValue)) {
+                    error(Diagnostics.Invalid_regular_expression_literal);
+                }
+
                 token = SyntaxKind.RegularExpressionLiteral;
             }
             return token;

tests/baselines/reference/parser579071.errors.txt

@@ -0,0 +1,7 @@
+tests/cases/conformance/parser/ecmascript5/RegressionTests/parser579071.ts(1,15): error TS17006: Invalid regular expression literal.
+
+
+==== tests/cases/conformance/parser/ecmascript5/RegressionTests/parser579071.ts (1 errors) ====
+    var x = /fo(o/;
+
+!!! error TS17006: Invalid regular expression literal.

tests/baselines/reference/parserRegularExpressionDivideAmbiguity4.errors.txt

@@ -1,6 +1,6 @@
 tests/cases/conformance/parser/ecmascript5/RegularExpressions/parserRegularExpressionDivideAmbiguity4.ts(1,1): error TS2304: Cannot find name 'foo'.
 tests/cases/conformance/parser/ecmascript5/RegularExpressions/parserRegularExpressionDivideAmbiguity4.ts(1,6): error TS1161: Unterminated regular expression literal.
-tests/cases/conformance/parser/ecmascript5/RegularExpressions/parserRegularExpressionDivideAmbiguity4.ts(1,17): error TS1005: ')' expected.
+tests/cases/conformance/parser/ecmascript5/RegularExpressions/parserRegularExpressionDivideAmbiguity4.ts(1,17): error TS17006: Invalid regular expression literal.
 
 
 ==== tests/cases/conformance/parser/ecmascript5/RegularExpressions/parserRegularExpressionDivideAmbiguity4.ts (3 errors) ====
@@ -10,4 +10,4 @@ tests/cases/conformance/parser/ecmascript5/RegularExpressions/parserRegularExpre
 
 !!! error TS1161: Unterminated regular expression literal.
 
-!!! error TS1005: ')' expected.
+!!! error TS17006: Invalid regular expression literal.