1 | "use strict";
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2 | module.exports = function(Promise, tryConvertToPromise, NEXT_FILTER) {
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3 | var util = require("./util");
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4 | var CancellationError = Promise.CancellationError;
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5 | var errorObj = util.errorObj;
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6 | var catchFilter = require("./catch_filter")(NEXT_FILTER);
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7 |
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8 | function PassThroughHandlerContext(promise, type, handler) {
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9 | this.promise = promise;
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10 | this.type = type;
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11 | this.handler = handler;
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12 | this.called = false;
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13 | this.cancelPromise = null;
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14 | }
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15 |
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16 | PassThroughHandlerContext.prototype.isFinallyHandler = function() {
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17 | return this.type === 0;
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18 | };
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19 |
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20 | function FinallyHandlerCancelReaction(finallyHandler) {
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21 | this.finallyHandler = finallyHandler;
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22 | }
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23 |
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24 | FinallyHandlerCancelReaction.prototype._resultCancelled = function() {
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25 | checkCancel(this.finallyHandler);
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26 | };
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27 |
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28 | function checkCancel(ctx, reason) {
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29 | if (ctx.cancelPromise != null) {
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30 | if (arguments.length > 1) {
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31 | ctx.cancelPromise._reject(reason);
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32 | } else {
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33 | ctx.cancelPromise._cancel();
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34 | }
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35 | ctx.cancelPromise = null;
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36 | return true;
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37 | }
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38 | return false;
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39 | }
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40 |
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41 | function succeed() {
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42 | return finallyHandler.call(this, this.promise._target()._settledValue());
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43 | }
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44 | function fail(reason) {
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45 | if (checkCancel(this, reason)) return;
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46 | errorObj.e = reason;
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47 | return errorObj;
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48 | }
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49 | function finallyHandler(reasonOrValue) {
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50 | var promise = this.promise;
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51 | var handler = this.handler;
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52 |
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53 | if (!this.called) {
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54 | this.called = true;
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55 | var ret = this.isFinallyHandler()
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56 | ? handler.call(promise._boundValue())
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57 | : handler.call(promise._boundValue(), reasonOrValue);
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58 | if (ret === NEXT_FILTER) {
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59 | return ret;
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60 | } else if (ret !== undefined) {
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61 | promise._setReturnedNonUndefined();
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62 | var maybePromise = tryConvertToPromise(ret, promise);
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63 | if (maybePromise instanceof Promise) {
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64 | if (this.cancelPromise != null) {
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65 | if (maybePromise._isCancelled()) {
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66 | var reason =
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67 | new CancellationError("late cancellation observer");
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68 | promise._attachExtraTrace(reason);
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69 | errorObj.e = reason;
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70 | return errorObj;
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71 | } else if (maybePromise.isPending()) {
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72 | maybePromise._attachCancellationCallback(
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73 | new FinallyHandlerCancelReaction(this));
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74 | }
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75 | }
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76 | return maybePromise._then(
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77 | succeed, fail, undefined, this, undefined);
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78 | }
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79 | }
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80 | }
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81 |
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82 | if (promise.isRejected()) {
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83 | checkCancel(this);
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84 | errorObj.e = reasonOrValue;
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85 | return errorObj;
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86 | } else {
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87 | checkCancel(this);
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88 | return reasonOrValue;
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89 | }
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90 | }
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91 |
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92 | Promise.prototype._passThrough = function(handler, type, success, fail) {
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93 | if (typeof handler !== "function") return this.then();
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94 | return this._then(success,
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95 | fail,
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96 | undefined,
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97 | new PassThroughHandlerContext(this, type, handler),
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98 | undefined);
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99 | };
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100 |
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101 | Promise.prototype.lastly =
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102 | Promise.prototype["finally"] = function (handler) {
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103 | return this._passThrough(handler,
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104 | 0,
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105 | finallyHandler,
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106 | finallyHandler);
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107 | };
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108 |
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109 |
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110 | Promise.prototype.tap = function (handler) {
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111 | return this._passThrough(handler, 1, finallyHandler);
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112 | };
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113 |
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114 | Promise.prototype.tapCatch = function (handlerOrPredicate) {
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115 | var len = arguments.length;
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116 | if(len === 1) {
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117 | return this._passThrough(handlerOrPredicate,
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118 | 1,
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119 | undefined,
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120 | finallyHandler);
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121 | } else {
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122 | var catchInstances = new Array(len - 1),
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123 | j = 0, i;
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124 | for (i = 0; i < len - 1; ++i) {
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125 | var item = arguments[i];
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126 | if (util.isObject(item)) {
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127 | catchInstances[j++] = item;
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128 | } else {
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129 | return Promise.reject(new TypeError(
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130 | "tapCatch statement predicate: "
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131 | + "expecting an object but got " + util.classString(item)
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132 | ));
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133 | }
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134 | }
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135 | catchInstances.length = j;
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136 | var handler = arguments[i];
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137 | return this._passThrough(catchFilter(catchInstances, handler, this),
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138 | 1,
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139 | undefined,
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140 | finallyHandler);
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141 | }
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142 |
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143 | };
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144 |
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145 | return PassThroughHandlerContext;
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146 | };
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