index.js 5.4 KB

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  1. "use strict";
  2. var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
  3. function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
  4. return new (P || (P = Promise))(function (resolve, reject) {
  5. function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
  6. function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
  7. function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
  8. step((generator = generator.apply(thisArg, _arguments || [])).next());
  9. });
  10. };
  11. Object.defineProperty(exports, "__esModule", { value: true });
  12. exports.isBinaryFileSync = exports.isBinaryFile = void 0;
  13. const fs = require("fs");
  14. const util_1 = require("util");
  15. const statAsync = util_1.promisify(fs.stat);
  16. const openAsync = util_1.promisify(fs.open);
  17. const closeAsync = util_1.promisify(fs.close);
  18. const MAX_BYTES = 512;
  19. function isBinaryFile(file, size) {
  20. return __awaiter(this, void 0, void 0, function* () {
  21. if (isString(file)) {
  22. const stat = yield statAsync(file);
  23. isStatFile(stat);
  24. const fileDescriptor = yield openAsync(file, 'r');
  25. const allocBuffer = Buffer.alloc(MAX_BYTES);
  26. // Read the file with no encoding for raw buffer access.
  27. // NB: something is severely wrong with promisify, had to construct my own Promise
  28. return new Promise((fulfill, reject) => {
  29. fs.read(fileDescriptor, allocBuffer, 0, MAX_BYTES, 0, (err, bytesRead, _) => {
  30. closeAsync(fileDescriptor);
  31. if (err) {
  32. reject(err);
  33. }
  34. else {
  35. fulfill(isBinaryCheck(allocBuffer, bytesRead));
  36. }
  37. });
  38. });
  39. }
  40. else {
  41. if (size === undefined) {
  42. size = file.length;
  43. }
  44. return isBinaryCheck(file, size);
  45. }
  46. });
  47. }
  48. exports.isBinaryFile = isBinaryFile;
  49. function isBinaryFileSync(file, size) {
  50. if (isString(file)) {
  51. const stat = fs.statSync(file);
  52. isStatFile(stat);
  53. const fileDescriptor = fs.openSync(file, 'r');
  54. const allocBuffer = Buffer.alloc(MAX_BYTES);
  55. const bytesRead = fs.readSync(fileDescriptor, allocBuffer, 0, MAX_BYTES, 0);
  56. fs.closeSync(fileDescriptor);
  57. return isBinaryCheck(allocBuffer, bytesRead);
  58. }
  59. else {
  60. if (size === undefined) {
  61. size = file.length;
  62. }
  63. return isBinaryCheck(file, size);
  64. }
  65. }
  66. exports.isBinaryFileSync = isBinaryFileSync;
  67. function isBinaryCheck(fileBuffer, bytesRead) {
  68. // empty file. no clue what it is.
  69. if (bytesRead === 0) {
  70. return false;
  71. }
  72. let suspiciousBytes = 0;
  73. const totalBytes = Math.min(bytesRead, MAX_BYTES);
  74. // UTF-8 BOM
  75. if (bytesRead >= 3 && fileBuffer[0] === 0xef && fileBuffer[1] === 0xbb && fileBuffer[2] === 0xbf) {
  76. return false;
  77. }
  78. // UTF-32 BOM
  79. if (bytesRead >= 4 &&
  80. fileBuffer[0] === 0x00 &&
  81. fileBuffer[1] === 0x00 &&
  82. fileBuffer[2] === 0xfe &&
  83. fileBuffer[3] === 0xff) {
  84. return false;
  85. }
  86. // UTF-32 LE BOM
  87. if (bytesRead >= 4 &&
  88. fileBuffer[0] === 0xff &&
  89. fileBuffer[1] === 0xfe &&
  90. fileBuffer[2] === 0x00 &&
  91. fileBuffer[3] === 0x00) {
  92. return false;
  93. }
  94. // GB BOM
  95. if (bytesRead >= 4 &&
  96. fileBuffer[0] === 0x84 &&
  97. fileBuffer[1] === 0x31 &&
  98. fileBuffer[2] === 0x95 &&
  99. fileBuffer[3] === 0x33) {
  100. return false;
  101. }
  102. if (totalBytes >= 5 && fileBuffer.slice(0, 5).toString() === '%PDF-') {
  103. /* PDF. This is binary. */
  104. return true;
  105. }
  106. // UTF-16 BE BOM
  107. if (bytesRead >= 2 && fileBuffer[0] === 0xfe && fileBuffer[1] === 0xff) {
  108. return false;
  109. }
  110. // UTF-16 LE BOM
  111. if (bytesRead >= 2 && fileBuffer[0] === 0xff && fileBuffer[1] === 0xfe) {
  112. return false;
  113. }
  114. for (let i = 0; i < totalBytes; i++) {
  115. if (fileBuffer[i] === 0) {
  116. // NULL byte--it's binary!
  117. return true;
  118. }
  119. else if ((fileBuffer[i] < 7 || fileBuffer[i] > 14) && (fileBuffer[i] < 32 || fileBuffer[i] > 127)) {
  120. // UTF-8 detection
  121. if (fileBuffer[i] > 193 && fileBuffer[i] < 224 && i + 1 < totalBytes) {
  122. i++;
  123. if (fileBuffer[i] > 127 && fileBuffer[i] < 192) {
  124. continue;
  125. }
  126. }
  127. else if (fileBuffer[i] > 223 && fileBuffer[i] < 240 && i + 2 < totalBytes) {
  128. i++;
  129. if (fileBuffer[i] > 127 && fileBuffer[i] < 192 && fileBuffer[i + 1] > 127 && fileBuffer[i + 1] < 192) {
  130. i++;
  131. continue;
  132. }
  133. }
  134. suspiciousBytes++;
  135. // Read at least 32 fileBuffer before making a decision
  136. if (i > 32 && (suspiciousBytes * 100) / totalBytes > 10) {
  137. return true;
  138. }
  139. }
  140. }
  141. if ((suspiciousBytes * 100) / totalBytes > 10) {
  142. return true;
  143. }
  144. return false;
  145. }
  146. function isString(x) {
  147. return typeof x === 'string';
  148. }
  149. function isStatFile(stat) {
  150. if (!stat.isFile()) {
  151. throw new Error(`Path provided was not a file!`);
  152. }
  153. }