feat: add allowRegexCharacters to no-useless-escape (#19705)

sethamus · web-flow · commit 07c1a7e839ec · 2025-05-13T15:07:43.000+02:00
* feat: add allowedCharacters to no-useless-escape

* rename option

* fix examples
diff --git a/docs/src/rules/no-useless-escape.md b/docs/src/rules/no-useless-escape.md
@@ -67,6 +67,42 @@ Examples of **correct** code for this rule:
 
 :::
 
+## Options
+
+This rule has an object option:
+
+* `allowRegexCharacters` - An array of characters that should be allowed to have unnecessary escapes in regular expressions. This is useful for characters like `-` where escaping can prevent accidental character ranges. For example, in `/[0\-]/`, the escape is technically unnecessary but helps prevent the pattern from becoming a range if another character is added later (e.g., `/[0\-9]/` vs `/[0-9]/`).
+
+### allowRegexCharacters
+
+Examples of **incorrect** code for the `{ "allowRegexCharacters": ["-"] }` option:
+
+::: incorrect
+
+```js
+/*eslint no-useless-escape: ["error", { "allowRegexCharacters": ["-"] }]*/
+
+/\!/;
+/\@/;
+/[a-z\^]/;
+```
+
+:::
+
+Examples of **correct** code for the `{ "allowRegexCharacters": ["-"] }` option:
+
+::: correct
+
+```js
+/*eslint no-useless-escape: ["error", { "allowRegexCharacters": ["-"] }]*/
+
+/[0\-]/;
+/[\-9]/;
+/a\-b/;
+```
+
+:::
+
 ## When Not To Use It
 
 If you don't want to be notified about unnecessary escapes, you can safely disable this rule.
diff --git a/lib/rules/no-useless-escape.js b/lib/rules/no-useless-escape.js
@@ -60,6 +60,12 @@ module.exports = {
 	meta: {
 		type: "suggestion",
 
+		defaultOptions: [
+			{
+				allowRegexCharacters: [],
+			},
+		],
+
 		docs: {
 			description: "Disallow unnecessary escape characters",
 			recommended: true,
@@ -78,11 +84,26 @@ module.exports = {
 				"Replace the `\\` with `\\\\` to include the actual backslash character.",
 		},
 
-		schema: [],
+		schema: [
+			{
+				type: "object",
+				properties: {
+					allowRegexCharacters: {
+						type: "array",
+						items: {
+							type: "string",
+						},
+						uniqueItems: true,
+					},
+				},
+				additionalProperties: false,
+			},
+		],
 	},
 
 	create(context) {
 		const sourceCode = context.sourceCode;
+		const [{ allowRegexCharacters }] = context.options;
 		const parser = new RegExpParser();
 
 		/**
@@ -217,7 +238,8 @@ module.exports = {
 
 					if (
 						escapedChar !==
-						String.fromCodePoint(characterNode.value)
+							String.fromCodePoint(characterNode.value) ||
+						allowRegexCharacters.includes(escapedChar)
 					) {
 						// It's a valid escape.
 						return;
diff --git a/lib/types/rules.d.ts b/lib/types/rules.d.ts
@@ -4141,7 +4141,13 @@ export interface ESLintRules extends Linter.RulesRecord {
 	 * @since 2.5.0
 	 * @see https://eslint.org/docs/latest/rules/no-useless-escape
 	 */
-	"no-useless-escape": Linter.RuleEntry<[]>;
+	"no-useless-escape": Linter.RuleEntry<
+		[
+			Partial<{
+				allowRegexCharacters: string[];
+			}>,
+		]
+	>;
 
 	/**
 	 * Rule to disallow renaming import, export, and destructured assignments to the same name.
diff --git a/tests/lib/rules/no-useless-escape.js b/tests/lib/rules/no-useless-escape.js
