Suggested changes to #2026 (Implement RegExp literal syntax checking)

internal/regexpchecker/tables.go

@@ -550,10 +550,10 @@ func isValidNonBinaryUnicodePropertyName(name string) bool {
 
 func isValidUnicodeProperty(name, value string) bool {
 	canonicalName := nonBinaryUnicodePropertyNames[name]
-	if canonicalName == "General_Category" {
+	switch canonicalName {
+	case "General_Category":
 		return generalCategoryValues.Has(value)
-	}
-	if canonicalName == "Script" || canonicalName == "Script_Extensions" {
+	case "Script", "Script_Extensions":
 		return scriptValues.Has(value)
 	}
 	return false

internal/regexpchecker/utf16.go

@@ -106,10 +106,18 @@ func utf16Length(s string) int {
 		return 1
 	}
 
-	// Otherwise, count UTF-16 code units from UTF-8 runes
+	// Otherwise, count UTF-16 code units from UTF-8 string
+	sLength := len(s)
 	length := 0
-	for _, r := range s {
-		length += charSize(r)
+	// ASCII fast path similar to stdlib utf8.RuneCount
+	for ; length < sLength; length++ {
+		if ch := s[length]; ch == 0 || ch >= utf8.RuneSelf {
+			// non-ASCII slow path, count from runes
+			for _, r := range s[length:] {
+				length += charSize(r)
+			}
+			return length
+		}
 	}
 	return length
 }

internal/scanner/scanner.go

@@ -1401,7 +1401,7 @@ func (s *Scanner) scanIdentifier(prefixLength int) bool {
 		for {
 			s.pos++
 			ch = s.char()
-			if !(isWordCharacter(ch) || ch == '$') {
+			if !(IsWordCharacter(ch) || ch == '$') {
 				break
 			}
 		}
@@ -2007,7 +2007,7 @@ func IsValidIdentifier(s string) bool {
 }
 
 // Section 6.1.4
-func isWordCharacter(ch rune) bool {
+func IsWordCharacter(ch rune) bool {
 	return stringutil.IsASCIILetter(ch) || stringutil.IsDigit(ch) || ch == '_'
 }
 
@@ -2020,7 +2020,7 @@ func IsIdentifierPart(ch rune) bool {
 }
 
 func IsIdentifierPartEx(ch rune, languageVariant core.LanguageVariant) bool {
-	return isWordCharacter(ch) || ch == '$' ||
+	return IsWordCharacter(ch) || ch == '$' ||
 		ch >= utf8.RuneSelf && isUnicodeIdentifierPart(ch) ||
 		languageVariant == core.LanguageVariantJSX && (ch == '-' || ch == ':') // "-" and ":" are valid in JSX Identifiers
 }

testdata/baselines/reference/compiler/regularExpressionDuplicateCapturingGroupName.errors.txt

@@ -0,0 +1,106 @@
+regularExpressionDuplicateCapturingGroupName.ts(2,13): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(3,14): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(4,15): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(5,16): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(6,16): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(7,18): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(8,16): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(9,18): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(11,19): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(12,21): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(14,20): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(15,20): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(16,20): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(19,12): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(20,13): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(23,50): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(23,57): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(23,64): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(24,35): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(24,42): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(24,66): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(24,74): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(24,81): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+regularExpressionDuplicateCapturingGroupName.ts(24,89): error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+
+
+==== regularExpressionDuplicateCapturingGroupName.ts (24 errors) ====
+    // Adjacent homonymous capturing groups
+    /(?<foo>)(?<foo>)/;
+                ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /(?<foo>)((?<foo>))/;
+                 ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /((?<foo>))(?<foo>)/;
+                  ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /((?<foo>))((?<foo>))/;
+                   ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /(?<foo>)(?=(?<foo>))/;
+                   ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /(?<=(?<foo>))(?<foo>)/;
+                     ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /(?<foo>)(?!(?<foo>))/;
+                   ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /(?<!(?<foo>))(?<foo>)/;
+                     ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+
+    /((?<foo>))((?=(?<foo>)))/;
+                      ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /((?<!(?<foo>)))((?<foo>))/;
+                        ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+
+    /(?=(?<foo>))(?=(?<foo>))/;
+                       ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /(?!(?<foo>))(?!(?<foo>))/;
+                       ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /(?=(?<foo>))(?!(?<foo>))/;
+                       ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+
+    // Nested homonymous capturing groups
+    /(?<foo>(?<foo>))/;
+               ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /(?<foo>((?<foo>)))/;
+                ~~~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+
+    // Complicated cases
+    /(?<a>)((?<b>)((?<c>)|(?<d>))|(?<b>)|((?<c>)))(?<c>)((?<b>)|(?<d>))/;
+                                                     ~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+                                                            ~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+                                                                   ~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+    /(?<a>)(((?<b>)|(?<c>))((?<d>)|(?<a>)|(?<b>))|(?<c>)|((?<d>)))(?<a>)(((?<b>)|(?<c>))|(?<d>))/;
+                                      ~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+                                             ~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+                                                                     ~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+                                                                             ~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+                                                                                    ~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+                                                                                            ~
+!!! error TS1515: Named capturing groups with the same name must be mutually exclusive to each other.
+
+    // Should not error
+    /(?<foo>)|(?<foo>)/;
+    /(?<foo>)|((?<foo>))/;
+    /((?<foo>))|(?<foo>)/;
+    /((?<foo>))|((?<foo>))/;
+

testdata/baselines/reference/compiler/regularExpressionDuplicateCapturingGroupName.js

@@ -0,0 +1,61 @@
+//// [tests/cases/compiler/regularExpressionDuplicateCapturingGroupName.ts] ////
+
+//// [regularExpressionDuplicateCapturingGroupName.ts]
+// Adjacent homonymous capturing groups
+/(?<foo>)(?<foo>)/;
+/(?<foo>)((?<foo>))/;
+/((?<foo>))(?<foo>)/;
+/((?<foo>))((?<foo>))/;
+/(?<foo>)(?=(?<foo>))/;
+/(?<=(?<foo>))(?<foo>)/;
+/(?<foo>)(?!(?<foo>))/;
+/(?<!(?<foo>))(?<foo>)/;
+
+/((?<foo>))((?=(?<foo>)))/;
+/((?<!(?<foo>)))((?<foo>))/;
+
+/(?=(?<foo>))(?=(?<foo>))/;
+/(?!(?<foo>))(?!(?<foo>))/;
+/(?=(?<foo>))(?!(?<foo>))/;
+
+// Nested homonymous capturing groups
+/(?<foo>(?<foo>))/;
+/(?<foo>((?<foo>)))/;
+
+// Complicated cases
+/(?<a>)((?<b>)((?<c>)|(?<d>))|(?<b>)|((?<c>)))(?<c>)((?<b>)|(?<d>))/;
+/(?<a>)(((?<b>)|(?<c>))((?<d>)|(?<a>)|(?<b>))|(?<c>)|((?<d>)))(?<a>)(((?<b>)|(?<c>))|(?<d>))/;
+
+// Should not error
+/(?<foo>)|(?<foo>)/;
+/(?<foo>)|((?<foo>))/;
+/((?<foo>))|(?<foo>)/;
+/((?<foo>))|((?<foo>))/;
+
+
+//// [regularExpressionDuplicateCapturingGroupName.js]
+// Adjacent homonymous capturing groups
+/(?<foo>)(?<foo>)/;
+/(?<foo>)((?<foo>))/;
+/((?<foo>))(?<foo>)/;
+/((?<foo>))((?<foo>))/;
+/(?<foo>)(?=(?<foo>))/;
+/(?<=(?<foo>))(?<foo>)/;
+/(?<foo>)(?!(?<foo>))/;
+/(?<!(?<foo>))(?<foo>)/;
+/((?<foo>))((?=(?<foo>)))/;
+/((?<!(?<foo>)))((?<foo>))/;
+/(?=(?<foo>))(?=(?<foo>))/;
+/(?!(?<foo>))(?!(?<foo>))/;
+/(?=(?<foo>))(?!(?<foo>))/;
+// Nested homonymous capturing groups
+/(?<foo>(?<foo>))/;
+/(?<foo>((?<foo>)))/;
+// Complicated cases
+/(?<a>)((?<b>)((?<c>)|(?<d>))|(?<b>)|((?<c>)))(?<c>)((?<b>)|(?<d>))/;
+/(?<a>)(((?<b>)|(?<c>))((?<d>)|(?<a>)|(?<b>))|(?<c>)|((?<d>)))(?<a>)(((?<b>)|(?<c>))|(?<d>))/;
+// Should not error
+/(?<foo>)|(?<foo>)/;
+/(?<foo>)|((?<foo>))/;
+/((?<foo>))|(?<foo>)/;
+/((?<foo>))|((?<foo>))/;

testdata/baselines/reference/compiler/regularExpressionDuplicateCapturingGroupName.symbols

@@ -0,0 +1,35 @@
+//// [tests/cases/compiler/regularExpressionDuplicateCapturingGroupName.ts] ////
+
+=== regularExpressionDuplicateCapturingGroupName.ts ===
+
+// Adjacent homonymous capturing groups
+/(?<foo>)(?<foo>)/;
+/(?<foo>)((?<foo>))/;
+/((?<foo>))(?<foo>)/;
+/((?<foo>))((?<foo>))/;
+/(?<foo>)(?=(?<foo>))/;
+/(?<=(?<foo>))(?<foo>)/;
+/(?<foo>)(?!(?<foo>))/;
+/(?<!(?<foo>))(?<foo>)/;
+
+/((?<foo>))((?=(?<foo>)))/;
+/((?<!(?<foo>)))((?<foo>))/;
+
+/(?=(?<foo>))(?=(?<foo>))/;
+/(?!(?<foo>))(?!(?<foo>))/;
+/(?=(?<foo>))(?!(?<foo>))/;
+
+// Nested homonymous capturing groups
+/(?<foo>(?<foo>))/;
+/(?<foo>((?<foo>)))/;
+
+// Complicated cases
+/(?<a>)((?<b>)((?<c>)|(?<d>))|(?<b>)|((?<c>)))(?<c>)((?<b>)|(?<d>))/;
+/(?<a>)(((?<b>)|(?<c>))((?<d>)|(?<a>)|(?<b>))|(?<c>)|((?<d>)))(?<a>)(((?<b>)|(?<c>))|(?<d>))/;
+
+// Should not error
+/(?<foo>)|(?<foo>)/;
+/(?<foo>)|((?<foo>))/;
+/((?<foo>))|(?<foo>)/;
+/((?<foo>))|((?<foo>))/;
+

testdata/baselines/reference/compiler/regularExpressionDuplicateCapturingGroupName.types

@@ -0,0 +1,70 @@
+//// [tests/cases/compiler/regularExpressionDuplicateCapturingGroupName.ts] ////
+
+=== regularExpressionDuplicateCapturingGroupName.ts ===
+// Adjacent homonymous capturing groups
+/(?<foo>)(?<foo>)/;
+>/(?<foo>)(?<foo>)/ : RegExp
+
+/(?<foo>)((?<foo>))/;
+>/(?<foo>)((?<foo>))/ : RegExp
+
+/((?<foo>))(?<foo>)/;
+>/((?<foo>))(?<foo>)/ : RegExp
+
+/((?<foo>))((?<foo>))/;
+>/((?<foo>))((?<foo>))/ : RegExp
+
+/(?<foo>)(?=(?<foo>))/;
+>/(?<foo>)(?=(?<foo>))/ : RegExp
+
+/(?<=(?<foo>))(?<foo>)/;
+>/(?<=(?<foo>))(?<foo>)/ : RegExp
+
+/(?<foo>)(?!(?<foo>))/;
+>/(?<foo>)(?!(?<foo>))/ : RegExp
+
+/(?<!(?<foo>))(?<foo>)/;
+>/(?<!(?<foo>))(?<foo>)/ : RegExp
+
+/((?<foo>))((?=(?<foo>)))/;
+>/((?<foo>))((?=(?<foo>)))/ : RegExp
+
+/((?<!(?<foo>)))((?<foo>))/;
+>/((?<!(?<foo>)))((?<foo>))/ : RegExp
+
+/(?=(?<foo>))(?=(?<foo>))/;
+>/(?=(?<foo>))(?=(?<foo>))/ : RegExp
+
+/(?!(?<foo>))(?!(?<foo>))/;
+>/(?!(?<foo>))(?!(?<foo>))/ : RegExp
+
+/(?=(?<foo>))(?!(?<foo>))/;
+>/(?=(?<foo>))(?!(?<foo>))/ : RegExp
+
+// Nested homonymous capturing groups
+/(?<foo>(?<foo>))/;
+>/(?<foo>(?<foo>))/ : RegExp
+
+/(?<foo>((?<foo>)))/;
+>/(?<foo>((?<foo>)))/ : RegExp
+
+// Complicated cases
+/(?<a>)((?<b>)((?<c>)|(?<d>))|(?<b>)|((?<c>)))(?<c>)((?<b>)|(?<d>))/;
+>/(?<a>)((?<b>)((?<c>)|(?<d>))|(?<b>)|((?<c>)))(?<c>)((?<b>)|(?<d>))/ : RegExp
+
+/(?<a>)(((?<b>)|(?<c>))((?<d>)|(?<a>)|(?<b>))|(?<c>)|((?<d>)))(?<a>)(((?<b>)|(?<c>))|(?<d>))/;
+>/(?<a>)(((?<b>)|(?<c>))((?<d>)|(?<a>)|(?<b>))|(?<c>)|((?<d>)))(?<a>)(((?<b>)|(?<c>))|(?<d>))/ : RegExp
+
+// Should not error
+/(?<foo>)|(?<foo>)/;
+>/(?<foo>)|(?<foo>)/ : RegExp
+
+/(?<foo>)|((?<foo>))/;
+>/(?<foo>)|((?<foo>))/ : RegExp
+
+/((?<foo>))|(?<foo>)/;
+>/((?<foo>))|(?<foo>)/ : RegExp
+
+/((?<foo>))|((?<foo>))/;
+>/((?<foo>))|((?<foo>))/ : RegExp
+