bindNodeCallback returns incorrect result if undefined success argument in callback #2254

stusherwin · 2017-01-06T11:46:14Z

RxJS version:
5.0.0-beta.6 but bug is present in master as of f8ba77d

Code to reproduce:

let nodeFunction = function(param1: string, param2: string, callback: any) {
  // Bug only manifests when success parameter is implicitly undefined
  callback(null /*error*/); // no success parameter
}

Observable.bindNodeCallback(nodeFunction)('a', 'b')
  .subscribe(succ => console.log(succ));

Expected behavior:
undefined

Actual behavior:
[]

Additional information:
This is a bug IMO because it does not preserve the behaviour of the wrapped method. There are actual libraries in production that have this behaviour, e.g. node-sqlite3 (which is how I found it):

Database#get(sql, [param, ...], [callback])

Runs the SQL query with the specified parameters and calls the callback with the first result row afterwards [...] The signature of the callback is function(err, row) {}. If the result set is empty, the second parameter is undefined, otherwise it is an object containing the values for the first row.

The problem appears to be in this line:
https://github.com/ReactiveX/rxjs/blob/master/src/observable/BoundNodeCallbackObservable.ts#L109

It could be fixed with something like this:

if(!innerArgs.length) {
  subject.next(undefined);
} else {
  subject.next(innerArgs.length === 1 ? innerArgs[0] : innerArgs);
}

But there's probably a more elegant way of doing it!

The text was updated successfully, but these errors were encountered:

trxcllnt · 2017-01-08T00:47:27Z

@stusherwin you're right, that's the correct fix. Happy to review if you want to submit a PR.

…guments Emit undefined insteady of empty array by resulting Observable, when callback function is called without success parameters. Closes ReactiveX#2254

* fix(timeout): Cancels scheduled timeout, if no longer needed fixes #2134 * fix(timeoutWith): Cancels scheduled timeout, if no longer needed * build(npm-scripts): update debug_mocha npm script for node 6 * fix(VirtualAction): Block rescheduled VirtualActions from executing their scheduled work. VirtualActions are immutable so they can be inspected by the TestScheduler. In order to mirror rescheduled stateful Actions, rescheduled VirtualActions shouldn't execute if they've been rescheduled before execution. * fix(timeout): Update timeout and timeoutWith to recycle their scheduled timeout actions. The timeout and timeoutWith operators should dispose their scheduled timeout actions on unsubscription. Also, given the new scheduling architecture, they can recycle their scheduled actions so just one action is allocated per subscription. * test(timeout): Add types to timeout and timeoutWith specs * Fix merge conflicts * Fix timeoutWith to work with new Subscriber leak fix. * fix(timeout-spec): fix merge conflicts * fix(Subscription): fold ChildSubscription logic into Subscriber to prevent operators from leaking ChildSubscriptions. (#2360) The addition of ChildSubscription to fix #2244 accidentally introduced a different memory leak. Most operators that add and remove inner Subscriptions store the inner Subscriber instance, not the value returned by Subscription#add. When they try to remove the inner Subscription manually, nothing is removed, because the ChildSubscription wrapper instance is the one added to the subscriptions list. Fixes #2355 * chore(publish): 5.1.1 * Ignore coverage It's 5.5mb that people installing this don't need :) * feat(AjaxObservable) : support 'PATCH' request type Add support of the 'PATCH' request type based on the already existing 'PUT' request. * fix(subscribeToResult): accept array-like as result Accept array-like as a result to subscribe, so that Observable.from and operators using subscribeToResult have identical behaviour. * chore(ajax.patch): Adds test for ajax.patch * fix(forkJoin): add type signature for single observable with selector Add type signature for using forkJoin with single observable as first parameter and selector function as second parameter, so that typings would not prevent usage which is permitted and properly handled by operator. Closes #2347 * feat(webSocket): Add binaryType to config object Add binaryType to config object, so that it is possible to set that parameter on underlying socket before any data emits happen. Closes #2353 * fix(merge): return Observable when called with single lowerCaseO Return Observable when merge is called with single lower case observable, so that merge would always return Observable instance. * fix(bindNodeCallback): emit undefined when callback has no success arguments Emit undefined insteady of empty array by resulting Observable, when callback function is called without success parameters. Closes #2254 * chore(danger): update dangerfile to validate commit message * chore(*): correctly scope disabled `max-line-length` tslint rule The max line length is set to 150 in 'tslint.json'. In specific regions, it is desirable to allow longer lines, so these regions should be wrapped in comments like the following: ```js // Max line length enforced here. /* tslint:disable:max-line-length */ // Max line length NOT enforced here. /* tslint:enable:max-line-length */ <-- CORRECT // Max line length enforced here. ``` In many cases, the re-enabling comment incorrectly included `disable` instead of `enable` (as shown below), which essentially keeps the `max-line-length` **disabled** for the rest of the file: ```js // Max line length enforced here. /* tslint:disable:max-line-length */ // Max line length NOT enforced here. /* tslint:disable:max-line-length */ <-- INCORRECT // Max line length NOT enforced here. ``` This commit fixes these comments, so the `max-line-length` rule is properly enforced in regions that don't need longer lines. * fix(bindCallback): emit undefined when callback is without arguments In resulting Observable emit undefined when callback is called without parameters, instead of emitting empty array. * fix(mergeAll): introduce variant support <T, R> for mergeMap - closes #2372 * feat(windowTime): maxWindowSize parameter in windowTime operator Adds new parameter in windowTime operator to control how much values given window can emit. Closes #1301 * docs(ObservableInput): add ObservableInput and SubscribableOrPromise descriptions Add ObservableInput and SubscribableOrPromise interface descriptions, as well as link these interfaces in type descriptions of operators, so that users always know what kind of parameters they can pass to used methods. * fix(timeoutWith): update timeoutWith to work with new Subscriber leak fix changes

lock · 2018-06-06T19:41:02Z

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.

This was referenced Feb 5, 2017

fix(bindCallback): emit undefined when callback is without arguments #2328

Merged

fix(bindNodeCallback): emit undefined when callback has no success ar… #2329

Merged

jayphelps closed this as completed in #2329 Feb 14, 2017

lock bot locked as resolved and limited conversation to collaborators Jun 6, 2018

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bindNodeCallback returns incorrect result if undefined success argument in callback #2254

bindNodeCallback returns incorrect result if undefined success argument in callback #2254

stusherwin commented Jan 6, 2017 •

edited

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trxcllnt commented Jan 8, 2017

lock bot commented Jun 6, 2018

bindNodeCallback returns incorrect result if undefined success argument in callback #2254

bindNodeCallback returns incorrect result if undefined success argument in callback #2254

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stusherwin commented Jan 6, 2017 • edited Loading

trxcllnt commented Jan 8, 2017

lock bot commented Jun 6, 2018

stusherwin commented Jan 6, 2017 •

edited

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