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-rw-r--r--app/scripts/lib/nodeify.js15
-rw-r--r--test/unit/app/nodeify-test.js49
2 files changed, 57 insertions, 7 deletions
diff --git a/app/scripts/lib/nodeify.js b/app/scripts/lib/nodeify.js
index 25be6537b..a813ae679 100644
--- a/app/scripts/lib/nodeify.js
+++ b/app/scripts/lib/nodeify.js
@@ -1,5 +1,5 @@
const promiseToCallback = require('promise-to-callback')
-const noop = function () {}
+const callbackNoop = function (err) { if (err) throw err }
/**
* A generator that returns a function which, when passed a promise, can treat that promise as a node style callback.
@@ -11,6 +11,7 @@ const noop = function () {}
*/
module.exports = function nodeify (fn, context) {
return function () {
+ // parse arguments
const args = [].slice.call(arguments)
const lastArg = args[args.length - 1]
const lastArgIsCallback = typeof lastArg === 'function'
@@ -19,8 +20,16 @@ module.exports = function nodeify (fn, context) {
callback = lastArg
args.pop()
} else {
- callback = noop
+ callback = callbackNoop
}
- promiseToCallback(fn.apply(context, args))(callback)
+ // call the provided function and ensure result is a promise
+ let result
+ try {
+ result = Promise.resolve(fn.apply(context, args))
+ } catch (err) {
+ result = Promise.reject(err)
+ }
+ // wire up promise resolution to callback
+ promiseToCallback(result)(callback)
}
}
diff --git a/test/unit/app/nodeify-test.js b/test/unit/app/nodeify-test.js
index 938b76c68..0dafc6653 100644
--- a/test/unit/app/nodeify-test.js
+++ b/test/unit/app/nodeify-test.js
@@ -2,16 +2,16 @@ const assert = require('assert')
const nodeify = require('../../../app/scripts/lib/nodeify')
describe('nodeify', function () {
- var obj = {
+ const obj = {
foo: 'bar',
promiseFunc: function (a) {
- var solution = this.foo + a
+ const solution = this.foo + a
return Promise.resolve(solution)
},
}
it('should retain original context', function (done) {
- var nodified = nodeify(obj.promiseFunc, obj)
+ const nodified = nodeify(obj.promiseFunc, obj)
nodified('baz', function (err, res) {
if (!err) {
assert.equal(res, 'barbaz')
@@ -22,7 +22,7 @@ describe('nodeify', function () {
})
})
- it('should allow the last argument to not be a function', function (done) {
+ it('no callback - should allow the last argument to not be a function', function (done) {
const nodified = nodeify(obj.promiseFunc, obj)
try {
nodified('baz')
@@ -31,4 +31,45 @@ describe('nodeify', function () {
done(new Error('should not have thrown if the last argument is not a function'))
}
})
+
+ it('no callback - should asyncly throw an error if underlying function does', function (done) {
+ const nodified = nodeify(async () => { throw new Error('boom!') }, obj)
+ process.prependOnceListener('uncaughtException', function (err) {
+ assert.ok(err, 'got expected error')
+ assert.ok(err.message.includes('boom!'), 'got expected error message')
+ done()
+ })
+ try {
+ nodified('baz')
+ } catch (err) {
+ done(new Error('should not have thrown an error synchronously'))
+ }
+ })
+
+ it('sync functions - returns value', function (done) {
+ const nodified = nodeify(() => 42)
+ try {
+ nodified((err, result) => {
+ if (err) return done(new Error(`should not have thrown any error: ${err.message}`))
+ assert.equal(42, result, 'got expected result')
+ })
+ done()
+ } catch (err) {
+ done(new Error(`should not have thrown any error: ${err.message}`))
+ }
+ })
+
+ it('sync functions - handles errors', function (done) {
+ const nodified = nodeify(() => { throw new Error('boom!') })
+ try {
+ nodified((err, result) => {
+ if (result) return done(new Error('should not have returned any result'))
+ assert.ok(err, 'got expected error')
+ assert.ok(err.message.includes('boom!'), 'got expected error message')
+ })
+ done()
+ } catch (err) {
+ done(new Error(`should not have thrown any error: ${err.message}`))
+ }
+ })
})