diff --git a/boa/src/builtins/string/mod.rs b/boa/src/builtins/string/mod.rs index aa9b8d70f8..063b285e27 100644 --- a/boa/src/builtins/string/mod.rs +++ b/boa/src/builtins/string/mod.rs @@ -108,6 +108,7 @@ impl BuiltIn for String { .name(Self::NAME) .length(Self::LENGTH) .property("length", 0, attribute) + .static_method(Self::raw, "raw", 1) .static_method(Self::from_char_code, "fromCharCode", 1) .method(Self::char_at, "charAt", 1) .method(Self::char_code_at, "charCodeAt", 1) @@ -231,6 +232,78 @@ impl String { .ok_or_else(|| context.construct_type_error("'this' is not a string")) } + /// `String.prototype.raw( template, ...substitutions )` + /// + /// More information: + /// - [ECMAScript reference][spec] + /// - [MDN documentation][mdn] + /// + /// [spec]: https://tc39.es/ecma262/#sec-string.raw + /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/raw + pub(crate) fn raw(_: &JsValue, args: &[JsValue], context: &mut Context) -> JsResult { + let substitutions = args.get(1..).unwrap_or_default(); + + // 1. Let numberOfSubstitutions be the number of elements in substitutions. + let number_of_substitutions = substitutions.len(); + + // 2. Let cooked be ? ToObject(template). + let cooked = args.get_or_undefined(0).to_object(context)?; + + // 3. Let raw be ? ToObject(? Get(cooked, "raw")). + let raw = cooked.get("raw", context)?.to_object(context)?; + + // 4. Let literalSegments be ? LengthOfArrayLike(raw). + let literal_segments = raw.length_of_array_like(context)?; + + // 5. If literalSegments ≤ 0, return the empty String. + // This is not <= because a `usize` is always positive. + if literal_segments == 0 { + return Ok(JsString::empty().into()); + } + + // 6. Let stringElements be a new empty List. + let mut string_elements = vec![]; + + // 7. Let nextIndex be 0. + let mut next_index = 0; + // 8. Repeat, + loop { + // a. Let nextKey be ! ToString(𝔽(nextIndex)). + let next_key = next_index; + + // b. Let nextSeg be ? ToString(? Get(raw, nextKey)). + let next_seg = raw.get(next_key, context)?.to_string(context)?; + + // c. Append the code unit elements of nextSeg to the end of stringElements. + string_elements.extend(next_seg.encode_utf16()); + + // d. If nextIndex + 1 = literalSegments, then + if next_index + 1 == literal_segments { + // i. Return the String value whose code units are the elements in the List stringElements. + // If stringElements has no elements, the empty String is returned. + return Ok(StdString::from_utf16_lossy(&string_elements).into()); + } + + // e. If nextIndex < numberOfSubstitutions, let next be substitutions[nextIndex]. + let next = if next_index < number_of_substitutions { + substitutions.get_or_undefined(next_index).clone() + + // f. Else, let next be the empty String. + } else { + JsString::empty().into() + }; + + // g. Let nextSub be ? ToString(next). + let next_sub = next.to_string(context)?; + + // h. Append the code unit elements of nextSub to the end of stringElements. + string_elements.extend(next_sub.encode_utf16()); + + // i. Set nextIndex to nextIndex + 1. + next_index += 1; + } + } + /// `String.fromCharCode(...codePoints)` /// /// Construct a `String` from one or more code points (as numbers).