# All files / src/encoding unicode.ts

82% Statements 41/50
77.78% Branches 35/45
81.82% Functions 9/11
81.63% Lines 40/49

Press n or j to go to the next uncovered block, b, p or k for the previous block.

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96
    97
    98
    99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    6x

    6x

    1x

    34x

    34x

    1x

    33x

    6x

    1x

    34x

    34x

    1x

    1x

    33x

    68x
    68x
    68x
    68x
    68x
    68x

    68x

    68x

    68x
    30744x

    30744x
    29384x

    1360x

    68x

    68x

    68x
    2x
    66x

    66x

    68x

    6x

    1x

    15406x

    6x

    1x

    15406x

     import { Context, Recogniser } from '.';
    const match = require('../match').default;

    /**
     * This class matches UTF-16 and UTF-32, both big- and little-endian. The
     * BOM will be used if it is present.
     */
    export class UTF_16BE implements Recogniser {
      name() {
        return 'UTF-16BE';
      }

      match(det: Context) {
        var input = det.fRawInput;

        if (
          input.length >= 2 &&
          (input[0] & 0xff) == 0xfe &&
          (input[1] & 0xff) == 0xff
        ) {
          return match(det, this, 100); // confidence = 100
        }

        // TODO: Do some statistics to check for unsigned UTF-16BE
        return null;
      }
    }

    export class UTF_16LE implements Recogniser {
      name() {
        return 'UTF-16LE';
      }
      match(det: Context) {
        var input = det.fRawInput;

        if (
          input.length >= 2 &&
          (input[0] & 0xff) == 0xff &&
          (input[1] & 0xff) == 0xfe
        ) {
          // LE BOM is present.
          Iif (input.length >= 4 && input[2] == 0x00 && input[3] == 0x00) {
            // It is probably UTF-32 LE, not UTF-16
            return null;
          }
          return match(det, this, 100); // confidence = 100
        }

        // TODO: Do some statistics to check for unsigned UTF-16LE
        return null;
      }
    }

    interface WithGetChar {
      getChar(input: Uint8Array, index: number): number;
    }

    class UTF_32 implements Recogniser, WithGetChar {
      name() {
        return 'UTF-32';
      }

      getChar(input: Uint8Array, index: number): number {
        return -1;
      }

      match(det: Context) {
        var input = det.fRawInput,
          limit = (det.fRawLength / 4) * 4,
          numValid = 0,
          numInvalid = 0,
          hasBOM = false,
          confidence = 0;

        Iif (limit == 0) {
          return null;
        }

        Iif (this.getChar(input, 0) == 0x0000feff) {
          hasBOM = true;
        }

        for (var i = 0; i < limit; i += 4) {
          var ch = this.getChar(input, i);

          if (ch < 0 || ch >= 0x10ffff || (ch >= 0xd800 && ch <= 0xdfff)) {
            numInvalid += 1;
          } else {
            numValid += 1;
          }
        }

        // Cook up some sort of confidence score, based on presence of a BOM
        //    and the existence of valid and/or invalid multi-byte sequences.
        Iif (hasBOM && numInvalid == 0) {
          confidence = 100;
        } else Iif (hasBOM && numValid > numInvalid * 10) {
          confidence = 80;
        } else if (numValid > 3 && numInvalid == 0) {
          confidence = 100;
        } else Iif (numValid > 0 && numInvalid == 0) {
          confidence = 80;
        } else Iif (numValid > numInvalid * 10) {
          // Probably corrupt UTF-32BE data.  Valid sequences aren't likely by chance.
          confidence = 25;
        }

        // return confidence == 0 ? null : new CharsetMatch(det, this, confidence);
        return confidence == 0 ? null : match(det, this, confidence);
      }
    }

    export class UTF_32BE extends UTF_32 {
      name() {
        return 'UTF-32BE';
      }
      getChar(input: Uint8Array, index: number) {
        return (
          ((input[index + 0] & 0xff) << 24) |
          ((input[index + 1] & 0xff) << 16) |
          ((input[index + 2] & 0xff) << 8) |
          (input[index + 3] & 0xff)
        );
      }
    }

    export class UTF_32LE extends UTF_32 {
      name() {
        return 'UTF-32LE';
      }

      getChar(input: Uint8Array, index: number) {
        return (
          ((input[index + 3] & 0xff) << 24) |
          ((input[index + 2] & 0xff) << 16) |
          ((input[index + 1] & 0xff) << 8) |
          (input[index + 0] & 0xff)
        );
      }
    }