Moved pipeline/sequence to lib/promise

refs #9178

- continue with killing our global utils folder
- i haven't found any better naming for lib/promise
- so, require single files for now
- instead of doing `promiseLib = require('../lib/promise')`
- we can optimise the requires later
This commit is contained in:
kirrg001 2017-12-13 22:20:02 +01:00
commit 137016ab94
2 changed files with 48 additions and 0 deletions

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/**
* # Pipeline Utility
*
* Based on pipeline.js from when.js:
* https://github.com/cujojs/when/blob/3.7.4/pipeline.js
*/
var Promise = require('bluebird');
function pipeline(tasks /* initial arguments */) {
var args = Array.prototype.slice.call(arguments, 1),
runTask = function (task, args) {
// Self-optimizing function to run first task with multiple
// args using apply, but subsequent tasks via direct invocation
runTask = function (task, arg) {
return task(arg);
};
return task.apply(null, args);
};
// Resolve any promises for the arguments passed in first
return Promise.all(args).then(function (args) {
// Iterate through the tasks passing args from one into the next
return Promise.reduce(tasks, function (arg, task) {
return runTask(task, arg);
}, args);
});
}
module.exports = pipeline;

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var Promise = require('bluebird');
/**
* expects an array of functions returning a promise
*/
function sequence(tasks /* Any Arguments */) {
var args = Array.prototype.slice.call(arguments, 1);
return Promise.reduce(tasks, function (results, task) {
return task.apply(this, args).then(function (result) {
results.push(result);
return results;
});
}, []);
}
module.exports = sequence;