Function process

ts/codediff/__tests__/addcharacterdiffs_test.ts:184–192

(codes: CharacterDiff[], txt: string)

    const [beforeCodes, afterCodes] = codes;

    const process = function (codes: CharacterDiff[], txt: string) {
      return codes
        .map(function (code) {
          let part = txt.substring(code[1], code[2]);
          if (code[0] != null) part = '[' + part + ']';
          return part;
        })
        .join('');
    };

    const beforeActual = process(beforeCodes, beforeText),
      afterActual = process(afterCodes, afterText);