AliasPlugin.js 2.9 KB

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  1. /*
  2. MIT License http://www.opensource.org/licenses/mit-license.php
  3. Author Tobias Koppers @sokra
  4. */
  5. "use strict";
  6. const forEachBail = require("./forEachBail");
  7. /** @typedef {import("./Resolver")} Resolver */
  8. /** @typedef {import("./Resolver").ResolveStepHook} ResolveStepHook */
  9. /** @typedef {{alias: string|Array<string>|false, name: string, onlyModule?: boolean}} AliasOption */
  10. module.exports = class AliasPlugin {
  11. /**
  12. * @param {string | ResolveStepHook} source source
  13. * @param {AliasOption | Array<AliasOption>} options options
  14. * @param {string | ResolveStepHook} target target
  15. */
  16. constructor(source, options, target) {
  17. this.source = source;
  18. this.options = Array.isArray(options) ? options : [options];
  19. this.target = target;
  20. }
  21. /**
  22. * @param {Resolver} resolver the resolver
  23. * @returns {void}
  24. */
  25. apply(resolver) {
  26. const target = resolver.ensureHook(this.target);
  27. resolver
  28. .getHook(this.source)
  29. .tapAsync("AliasPlugin", (request, resolveContext, callback) => {
  30. const innerRequest = request.request || request.path;
  31. if (!innerRequest) return callback();
  32. forEachBail(
  33. this.options,
  34. (item, callback) => {
  35. let shouldStop = false;
  36. if (
  37. innerRequest === item.name ||
  38. (!item.onlyModule && innerRequest.startsWith(item.name + "/"))
  39. ) {
  40. const remainingRequest = innerRequest.substr(item.name.length);
  41. const resolveWithAlias = (alias, callback) => {
  42. if (alias === false) {
  43. const ignoreObj = {
  44. ...request,
  45. path: false
  46. };
  47. return callback(null, ignoreObj);
  48. }
  49. if (
  50. innerRequest !== alias &&
  51. !innerRequest.startsWith(alias + "/")
  52. ) {
  53. shouldStop = true;
  54. const newRequestStr = alias + remainingRequest;
  55. const obj = {
  56. ...request,
  57. request: newRequestStr,
  58. fullySpecified: false
  59. };
  60. return resolver.doResolve(
  61. target,
  62. obj,
  63. "aliased with mapping '" +
  64. item.name +
  65. "': '" +
  66. alias +
  67. "' to '" +
  68. newRequestStr +
  69. "'",
  70. resolveContext,
  71. (err, result) => {
  72. if (err) return callback(err);
  73. if (result) return callback(null, result);
  74. return callback();
  75. }
  76. );
  77. }
  78. return callback();
  79. };
  80. const stoppingCallback = (err, result) => {
  81. if (err) return callback(err);
  82. if (result) return callback(null, result);
  83. // Don't allow other aliasing or raw request
  84. if (shouldStop) return callback(null, null);
  85. return callback();
  86. };
  87. if (Array.isArray(item.alias)) {
  88. return forEachBail(
  89. item.alias,
  90. resolveWithAlias,
  91. stoppingCallback
  92. );
  93. } else {
  94. return resolveWithAlias(item.alias, stoppingCallback);
  95. }
  96. }
  97. return callback();
  98. },
  99. callback
  100. );
  101. });
  102. }
  103. };