index.js 3.6 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495
  1. /**
  2. * empower - Power Assert feature enhancer for assert function/object.
  3. *
  4. * https://github.com/power-assert-js/empower
  5. *
  6. * Copyright (c) 2013-2018 Takuto Wada
  7. * Licensed under the MIT license.
  8. * https://github.com/power-assert-js/empower/blob/master/MIT-LICENSE.txt
  9. */
  10. var empowerCore = require('empower-core');
  11. var defaultOptions = require('./lib/default-options');
  12. var capturable = require('./lib/capturable');
  13. var assign = require('core-js/library/fn/object/assign');
  14. var define = require('./lib/define-properties');
  15. /**
  16. * Enhance Power Assert feature to assert function/object.
  17. * @param assert target assert function or object to enhance
  18. * @param formatter power assert format function
  19. * @param options enhancement options
  20. * @return enhanced assert function/object
  21. */
  22. function empower (assert, formatter, options) {
  23. var config = assign(defaultOptions(), options);
  24. var eagerEvaluation = !(config.modifyMessageOnRethrow || config.saveContextOnRethrow);
  25. // see: https://github.com/power-assert-js/empower/pull/26
  26. var shouldRecreateAssertionError = (function isStackUnchanged () {
  27. if (typeof assert !== 'function') {
  28. return false;
  29. }
  30. if (typeof assert.AssertionError !== 'function') {
  31. return false;
  32. }
  33. var ae = new assert.AssertionError({
  34. actual: 123,
  35. expected: 456,
  36. operator: '==='
  37. });
  38. ae.message = '[REPLACED MESSAGE]';
  39. return !(/REPLACED MESSAGE/.test(ae.stack)) && /123 === 456/.test(ae.stack);
  40. })();
  41. var empowerCoreConfig = assign(config, {
  42. modifyMessageBeforeAssert: function (beforeAssertEvent) {
  43. var message = beforeAssertEvent.originalMessage;
  44. if (!eagerEvaluation) {
  45. return message;
  46. }
  47. return buildPowerAssertText(formatter, message, beforeAssertEvent.powerAssertContext);
  48. },
  49. onError: function onError (errorEvent) {
  50. var e = errorEvent.error;
  51. if (!/^AssertionError/.test(e.name)) {
  52. throw e;
  53. }
  54. if (!errorEvent.powerAssertContext) {
  55. throw e;
  56. }
  57. var poweredMessage;
  58. if (config.modifyMessageOnRethrow || config.saveContextOnRethrow) {
  59. poweredMessage = buildPowerAssertText(formatter, errorEvent.originalMessage, errorEvent.powerAssertContext);
  60. if (shouldRecreateAssertionError) {
  61. e = new assert.AssertionError({
  62. message: poweredMessage,
  63. actual: e.actual,
  64. expected: e.expected,
  65. operator: e.operator,
  66. stackStartFunction: e.stackStartFunction || onError
  67. });
  68. e.generatedMessage = false;
  69. }
  70. }
  71. if (config.modifyMessageOnRethrow && !shouldRecreateAssertionError) {
  72. e.message = poweredMessage;
  73. e.generatedMessage = false;
  74. }
  75. if (config.saveContextOnRethrow) {
  76. e.powerAssertContext = errorEvent.powerAssertContext;
  77. }
  78. throw e;
  79. }
  80. });
  81. var enhancedAssert = empowerCore(assert, empowerCoreConfig);
  82. define(enhancedAssert, capturable());
  83. return enhancedAssert;
  84. }
  85. function buildPowerAssertText (formatter, message, context) {
  86. // console.log(message);
  87. var powerAssertText = formatter(context);
  88. return message ? message + ' ' + powerAssertText : powerAssertText;
  89. };
  90. empower.defaultOptions = defaultOptions;
  91. module.exports = empower;