LibJS: Implement the RegExp.escape proposal

https://tc39.es/proposal-regex-escaping/
Author: https://github.com/trflynn89 Commit: db87f173fb Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2773 Reviewed-by: https://github.com/gmta
2025-08-21 09:49:21 +00:00 · 2024-12-04 17:12:42 -05:00 · 2024-12-04 17:12:42 -05:00 · db87f173fb · 2024-12-05 12:57:14 +00:00
commit db87f173fb
parent bd1009f3c1
3 changed files with 177 additions and 0 deletions
--- a/Libraries/LibJS/Tests/builtins/RegExp/RegExp.escape.js
+++ b/Libraries/LibJS/Tests/builtins/RegExp/RegExp.escape.js
@ -0,0 +1,68 @@
+describe("errors", () => {
+    test("invalid string", () => {
+        expect(() => {
+            RegExp.escape(Symbol.hasInstance);
+        }).toThrowWithMessage(TypeError, "Symbol(Symbol.hasInstance) is not a string");
+    });
+});
+
+describe("normal behavior", () => {
+    test("first character is alphanumeric", () => {
+        const alphanumeric = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+
+        for (const ch of alphanumeric) {
+            const string = `${ch}${ch}${ch}`;
+            const expected = `\\x${ch.codePointAt(0).toString(16)}${ch}${ch}`;
+
+            expect(RegExp.escape(string)).toBe(expected);
+        }
+    });
+
+    test("syntax characters", () => {
+        const syntaxCharacters = "^$\\.*+?()[]{}|/";
+
+        for (const ch of syntaxCharacters) {
+            const string = `_${ch}_`;
+            const expected = `_\\${ch}_`;
+
+            expect(RegExp.escape(string)).toBe(expected);
+        }
+    });
+
+    test("control characters", () => {
+        expect(RegExp.escape("_\t_")).toBe("_\\t_");
+        expect(RegExp.escape("_\n_")).toBe("_\\n_");
+        expect(RegExp.escape("_\v_")).toBe("_\\v_");
+        expect(RegExp.escape("_\f_")).toBe("_\\f_");
+        expect(RegExp.escape("_\r_")).toBe("_\\r_");
+    });
+
+    test("punctuators", () => {
+        const punctuators = ",-=<>#&!%:;@~'`\"";
+
+        for (const ch of punctuators) {
+            const string = `_${ch}_`;
+            const expected = `_\\x${ch.codePointAt(0).toString(16)}_`;
+
+            expect(RegExp.escape(string)).toBe(expected);
+        }
+    });
+
+    test("non-ASCII whitespace", () => {
+        const nbsp = "\u00A0";
+
+        expect(RegExp.escape("\u00A0")).toBe("\\xa0");
+        expect(RegExp.escape("\uFEFF")).toBe("\\ufeff");
+        expect(RegExp.escape("\u2028")).toBe("\\u2028");
+        expect(RegExp.escape("\u2029")).toBe("\\u2029");
+    });
+
+    test("Unicode surrogates", () => {
+        for (let ch = 0xd800; ch <= 0xdfff; ++ch) {
+            const string = String.fromCodePoint(ch);
+            const expected = `\\u${ch.toString(16)}`;
+
+            expect(RegExp.escape(string)).toBe(expected);
+        }
+    });
+});