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Diffstat (limited to 'node_modules/thenify/index.js')
| -rw-r--r-- | node_modules/thenify/index.js | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/node_modules/thenify/index.js b/node_modules/thenify/index.js new file mode 100644 index 0000000..d633174 --- /dev/null +++ b/node_modules/thenify/index.js @@ -0,0 +1,77 @@ + +var Promise = require('any-promise') +var assert = require('assert') + +module.exports = thenify + +/** + * Turn async functions into promises + * + * @param {Function} fn + * @return {Function} + * @api public + */ + +function thenify(fn, options) { + assert(typeof fn === 'function') + return createWrapper(fn, options) +} + +/** + * Turn async functions into promises and backward compatible with callback + * + * @param {Function} fn + * @return {Function} + * @api public + */ + +thenify.withCallback = function (fn, options) { + assert(typeof fn === 'function') + options = options || {} + options.withCallback = true + return createWrapper(fn, options) +} + +function createCallback(resolve, reject, multiArgs) { + // default to true + if (multiArgs === undefined) multiArgs = true + return function(err, value) { + if (err) return reject(err) + var length = arguments.length + + if (length <= 2 || !multiArgs) return resolve(value) + + if (Array.isArray(multiArgs)) { + var values = {} + for (var i = 1; i < length; i++) values[multiArgs[i - 1]] = arguments[i] + return resolve(values) + } + + var values = new Array(length - 1) + for (var i = 1; i < length; ++i) values[i - 1] = arguments[i] + resolve(values) + } +} + +function createWrapper(fn, options) { + options = options || {} + var name = fn.name; + name = (name || '').replace(/\s|bound(?!$)/g, '') + var newFn = function () { + var self = this + var len = arguments.length + if (options.withCallback) { + var lastType = typeof arguments[len - 1] + if (lastType === 'function') return fn.apply(self, arguments) + } + var args = new Array(len + 1) + for (var i = 0; i < len; ++i) args[i] = arguments[i] + var lastIndex = i + return new Promise(function (resolve, reject) { + args[lastIndex] = createCallback(resolve, reject, options.multiArgs) + fn.apply(self, args) + }) + } + Object.defineProperty(newFn, 'name', { value: name }) + return newFn +} |