25 lines
		
	
	
		
			673 B
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			25 lines
		
	
	
		
			673 B
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
"use strict";
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var ensurePlainFunction = require("type/plain-function/ensure")
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  , isThenable          = require("type/thenable/is")
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  , ensureThenable      = require("type/thenable/ensure");
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var resolveCallback = function (callback, next) {
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	var callbackResult = callback();
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	if (!isThenable(callbackResult)) return next();
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	return callbackResult.then(next);
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};
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module.exports = function (callback) {
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	ensureThenable(this);
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	ensurePlainFunction(callback);
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	return this.then(
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		function (result) {
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			return resolveCallback(callback, function () { return result; });
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		},
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		function (error) {
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			return resolveCallback(callback, function () { throw error; });
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		}
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	);
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};
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