import { isHexDigit, isWhiteSpace, isValidEscape, consumeEscaped, decodeEscaped } from '../tokenizer/index.js'; const SPACE = 0x0020; // U+0020 SPACE const REVERSE_SOLIDUS = 0x005c; // U+005C REVERSE SOLIDUS (\) const QUOTATION_MARK = 0x0022; // " const APOSTROPHE = 0x0027; // ' const LEFTPARENTHESIS = 0x0028; // U+0028 LEFT PARENTHESIS (() const RIGHTPARENTHESIS = 0x0029; // U+0029 RIGHT PARENTHESIS ()) export function decode(str) { const len = str.length; let start = 4; // length of "url(" let end = str.charCodeAt(len - 1) === RIGHTPARENTHESIS ? len - 2 : len - 1; let decoded = ''; while (start < end && isWhiteSpace(str.charCodeAt(start))) { start++; } while (start < end && isWhiteSpace(str.charCodeAt(end))) { end--; } for (let i = start; i <= end; i++) { let code = str.charCodeAt(i); if (code === REVERSE_SOLIDUS) { // special case at the ending if (i === end) { // if the next input code point is EOF, do nothing // otherwise include last left parenthesis as escaped if (i !== len - 1) { decoded = str.substr(i + 1); } break; } code = str.charCodeAt(++i); // consume escaped if (isValidEscape(REVERSE_SOLIDUS, code)) { const escapeStart = i - 1; const escapeEnd = consumeEscaped(str, escapeStart); i = escapeEnd - 1; decoded += decodeEscaped(str.substring(escapeStart + 1, escapeEnd)); } else { // \r\n if (code === 0x000d && str.charCodeAt(i + 1) === 0x000a) { i++; } } } else { decoded += str[i]; } } return decoded; } export function encode(str) { let encoded = ''; let wsBeforeHexIsNeeded = false; for (let i = 0; i < str.length; i++) { const code = str.charCodeAt(i); // If the character is NULL (U+0000), then the REPLACEMENT CHARACTER (U+FFFD). if (code === 0x0000) { encoded += '\uFFFD'; continue; } // If the character is in the range [\1-\1f] (U+0001 to U+001F) or is U+007F, // the character escaped as code point. // Note: Do not compare with 0x0001 since 0x0000 is precessed before if (code <= 0x001f || code === 0x007F) { encoded += '\\' + code.toString(16); wsBeforeHexIsNeeded = true; continue; } if (code === SPACE || code === REVERSE_SOLIDUS || code === QUOTATION_MARK || code === APOSTROPHE || code === LEFTPARENTHESIS || code === RIGHTPARENTHESIS) { encoded += '\\' + str.charAt(i); wsBeforeHexIsNeeded = false; } else { if (wsBeforeHexIsNeeded && isHexDigit(code)) { encoded += ' '; } encoded += str.charAt(i); wsBeforeHexIsNeeded = false; } } return 'url(' + encoded + ')'; }