Function consumeQuotedText

packages/core/src/render3/styling/styling_parser.ts:295–319

(
  text: string,
  quoteCharCode: number,
  startIndex: number,
  endIndex: number,
)

 * @returns Index after quoted characters.
 */
export function consumeQuotedText(
  text: string,
  quoteCharCode: number,
  startIndex: number,
  endIndex: number,
): number {
  let ch1 = -1; // 1st previous character
  let index = startIndex;
  while (index < endIndex) {
    const ch = text.charCodeAt(index++);
    if (ch == quoteCharCode && ch1 !== CharCode.BACK_SLASH) {
      return index;
    }
    if (ch == CharCode.BACK_SLASH && ch1 === CharCode.BACK_SLASH) {
      // two back slashes cancel each other out. For example `"\\"` should properly end the
      // quotation. (It should not assume that the last `"` is escaped.)
      ch1 = 0;
    } else {
      ch1 = ch;
    }
  }
  throw ngDevMode
    ? malformedStyleError(text, String.fromCharCode(quoteCharCode), endIndex)
    : new Error();
}

function malformedStyleError(text: string, expecting: string, index: number): never {
  ngDevMode && assertEqual(typeof text === 'string', true, 'String expected here');