LibJS: Add the global escape() & unescape() methods

Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h

@@ -99,6 +99,7 @@ namespace JS {
     P(entries)                               \
     P(enumerable)                            \
     P(error)                                 \
+    P(escape)                                \
     P(eval)                                  \
     P(every)                                 \
     P(exec)                                  \
@@ -263,6 +264,7 @@ namespace JS {
     P(trimStart)                             \
     P(trunc)                                 \
     P(undefined)                             \
+    P(unescape)                              \
     P(unicode)                               \
     P(unshift)                               \
     P(value)                                 \

Userland/Libraries/LibJS/Runtime/GlobalObject.cpp

@@ -112,6 +112,8 @@ void GlobalObject::initialize_global_object()
     define_native_function(vm.names.decodeURI, decode_uri, 1, attr);
     define_native_function(vm.names.encodeURIComponent, encode_uri_component, 1, attr);
     define_native_function(vm.names.decodeURIComponent, decode_uri_component, 1, attr);
+    define_native_function(vm.names.escape, escape, 1, attr);
+    define_native_function(vm.names.unescape, unescape, 1, attr);
 
     define_property(vm.names.NaN, js_nan(), 0);
     define_property(vm.names.Infinity, js_infinity(), 0);
@@ -433,4 +435,46 @@ JS_DEFINE_NATIVE_FUNCTION(GlobalObject::decode_uri_component)
     return js_string(vm, move(decoded));
 }
 
+JS_DEFINE_NATIVE_FUNCTION(GlobalObject::escape)
+{
+    auto string = vm.argument(0).to_string(global_object);
+    if (vm.exception())
+        return {};
+    StringBuilder escaped;
+    for (auto code_point : Utf8View(string)) {
+        if (code_point < 256) {
+            if ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789@*_+-./"sv.contains(code_point))
+                escaped.append(code_point);
+            else
+                escaped.appendff("%{:02X}", code_point);
+            continue;
+        }
+        escaped.appendff("%u{:04X}", code_point); // FIXME: Handle utf-16 surrogate pairs
+    }
+    return js_string(vm, escaped.build());
+}
+
+JS_DEFINE_NATIVE_FUNCTION(GlobalObject::unescape)
+{
+    auto string = vm.argument(0).to_string(global_object);
+    if (vm.exception())
+        return {};
+    ssize_t length = string.length();
+    StringBuilder unescaped(length);
+    for (auto k = 0; k < length; ++k) {
+        u32 code_point = string[k];
+        if (code_point == '%') {
+            if (k <= length - 6 && string[k + 1] == 'u' && is_ascii_hex_digit(string[k + 2]) && is_ascii_hex_digit(string[k + 3]) && is_ascii_hex_digit(string[k + 4]) && is_ascii_hex_digit(string[k + 5])) {
+                code_point = (parse_ascii_hex_digit(string[k + 2]) << 12) | (parse_ascii_hex_digit(string[k + 3]) << 8) | (parse_ascii_hex_digit(string[k + 4]) << 4) | parse_ascii_hex_digit(string[k + 5]);
+                k += 5;
+            } else if (k <= length - 3 && is_ascii_hex_digit(string[k + 1]) && is_ascii_hex_digit(string[k + 2])) {
+                code_point = (parse_ascii_hex_digit(string[k + 1]) << 4) | parse_ascii_hex_digit(string[k + 2]);
+                k += 2;
+            }
+        }
+        unescaped.append_code_point(code_point);
+    }
+    return js_string(vm, unescaped.build());
+}
+
 }

Userland/Libraries/LibJS/Runtime/GlobalObject.h

@@ -68,6 +68,8 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(decode_uri);
     JS_DECLARE_NATIVE_FUNCTION(encode_uri_component);
     JS_DECLARE_NATIVE_FUNCTION(decode_uri_component);
+    JS_DECLARE_NATIVE_FUNCTION(escape);
+    JS_DECLARE_NATIVE_FUNCTION(unescape);
 
     NonnullOwnPtr<Console> m_console;
 

Userland/Libraries/LibJS/Tests/builtins/functions/escapeUnescape.js

@@ -0,0 +1,21 @@
+test("escape", () => {
+    [
+        ["abc123", "abc123"],
+        ["äöü", "%E4%F6%FC"],
+        ["ć", "%u0107"],
+        ["@*_+-./", "@*_+-./"],
+    ].forEach(test => {
+        expect(escape(test[0])).toBe(test[1]);
+    });
+});
+
+test("unescape", () => {
+    [
+        ["abc123", "abc123"],
+        ["%E4%F6%FC", "äöü"],
+        ["%u0107", "ć"],
+        ["@*_+-./", "@*_+-./"],
+    ].forEach(test => {
+        expect(unescape(test[0])).toBe(test[1]);
+    });
+});