fix: not throw error when namedGroup is not enabled

README.md

@@ -103,7 +103,7 @@ Setting this option to `true` enables support for [named capture groups](https:/
 
 ```js
 rewritePattern('(?<name>.)\k<name>', '', {
-  'namedGroups': true
+  'namedGroup': true
 });
 // → '(.)\1'
 ```
@@ -115,7 +115,7 @@ the name of the group, and its index.
 
 ```js
 rewritePattern('(?<name>.)\k<name>', '', {
-  'namedGroups': true,
+  'namedGroup': true,
   onNamedGroup(name, index) {
     console.log(name, index);
     // → 'name', 1

demo.js

@@ -16,3 +16,11 @@ console.log(processedPattern);
 
 // throws
 new RegExp(processedPattern, 'u');
+
+console.log(rewritePattern('(?<name>.)\\k<name>', '', {
+	'namedGroup': true
+}))
+
+console.log(rewritePattern('(?<name>.)\\k<name>', '', {
+	'namedGroup': false
+}))

rewrite-pattern.js

@@ -174,8 +174,10 @@ const processCharacterClass = (characterClassItem, regenerateOptions) => {
 };
 
 const updateNamedReference = (item, index) => {
-	delete item.name;
-	item.matchIndex = index;
+	if (config.namedGroup) {
+		delete item.name;
+		item.matchIndex = index;
+	}
 };
 
 const assertNoUnmatchedReferences = (groups) => {
@@ -224,7 +226,7 @@ const processTerm = (item, regenerateOptions, groups) => {
 			if (item.behavior == 'normal') {
 				groups.lastIndex++;
 			}
-			if (item.name && config.namedGroup) {
+			if (item.name) {
 				const name = item.name.value;
 
 				if (groups.names[name]) {
@@ -234,7 +236,9 @@ const processTerm = (item, regenerateOptions, groups) => {
 				}
 
 				const index = groups.lastIndex;
-				delete item.name;
+				if (config.namedGroup) {
+					delete item.name;
+				}
 
 				groups.names[name] = index;
 				if (groups.onNamedGroup) {

tests/tests.js

@@ -869,6 +869,38 @@ describe('namedGroup', () => {
 		});
 		assert.strictEqual(expected, transpiled);
 	})
+
+	it('should not throw when namedGroup is not enabled', () => {
+		let transpiled;
+		const expected = '(?<name>.)\\k<name>';
+		assert.doesNotThrow(() => {
+			transpiled = rewritePattern('(?<name>.)\\k<name>', '');
+		});
+		assert.strictEqual(expected, transpiled);
+	})
+
+	it('should not throw when namedGroup is true', () => {
+		let transpiled;
+		const expected = '(.)\\1';
+		assert.doesNotThrow(() => {
+			transpiled = rewritePattern('(?<name>.)\\k<name>', '', {
+				namedGroup: true
+			});
+		});
+		assert.strictEqual(expected, transpiled);
+	})
+
+	it('should not throw when namedGroup is false', () => {
+		let transpiled;
+		const expected = '(?<name>.)\\k<name>';
+		assert.doesNotThrow(() => {
+			transpiled = rewritePattern('(?<name>.)\\k<name>', '', {
+				namedGroup: false
+			});
+		});
+		assert.strictEqual(expected, transpiled);
+	})
+
 });
 
 const lookbehindFixtures = [