Re: Re: Proposal to add keyword "nowait"

[Александр Ефремов]

It doesn't decide the whole problem. Because what to do with built-in api which 
returns promises (like `fetch`)? 
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Re: Re: Proposal to add keyword "nowait"

[Алексей]

I think it should not be hard to implement at least for explicitely async
functions. Of course it will miss non-async that return promises. But you
can mark them as async. For example we are doing on each function that
could return promise even if it doesn't use await. But even without it that
should hit most of missed await errors

2018-02-12 13:34 GMT+02:00 Александр Ефремов :

> I’m not sure that it will be simply to implement. Because not all possible
> to analyze without execution. I offer to use `nowait` there where calls
> will return promise, but it i’m not sure that promises always can detect
> just via parsing of source code.
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Re: Re: Proposal to add keyword "nowait"

[Александр Ефремов]

I’m not sure that it will be simply to implement. Because not all possible to 
analyze without execution. I offer to use `nowait` there where calls will 
return promise, but it i’m not sure that promises always can detect just via 
parsing of source code.
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Re: Proposal to add keyword "nowait"

[Michał Wadas]

I would solve such issue by having transpile step that inserts assertions
everywhere in dev enviroment (and don't add them in production env).

On Mon, Feb 12, 2018 at 6:41 AM, Александр Ефремов 
wrote:

> Sometimes when create the async functions forget to add await and later
> such mistake difficult to find.
> Maybe would be better always demand to add keyword nowait to calls
> returning promises which we don't plan to wait. But if this keyword and
> await keyword no exists then throw the error.
>
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Re: Re: Proposal to add keyword "nowait"

[Александр Ефремов]

Hm, yes, you are right.
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Re: Re: Proposal to add keyword "nowait"

[T.J. Crowder]

On Mon, Feb 12, 2018 at 10:28 AM, Александр Ефремов 
wrote:

> Hm, yes, you are right.
> That’s https://eslint.org/docs/rules/require-await
> Thank you very much.
> In the next I will be more dig.
>

That just warns you if you've made a function `async` pointlessly (which
may or may not be because you forgot an `await`). It won't help you if you
have at least one `await` but have forgotten *others*.

Static analysis (such as done by ESLint) cannot perfectly solve the problem
you and Steven Mascaro are trying to solve: Forgetting `await`s in all
necessary locations in an `async` function.

-- T.J. Crowder
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Re: Re: Proposal to add keyword "nowait"

[Александр Ефремов]

Hm, yes, you are right.
That’s https://eslint.org/docs/rules/require-await 

Thank you very much.
In the next I will be more dig.___
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Re: Proposal to add keyword "nowait"

[Alan Plum]

You could have a rule that could enforce always using `return await` in 
try/catch blocks in async functions. The `nowait` equivalent would be disabling 
that rule for that line.

For the `nobreak` example I gave this actually exists (the rule is called 
`no-fallthrough` and could be disabled per case individually to allow omitting 
the `break` keyword).

On Mon, Feb 12, 2018, at 10:52 AM, Александр Ефремов wrote:
> I don’t understand how you offer to decide it via eslint. Because 
> without additional keyword (`nowait`) it’s impossible to controlling. 
> But if doesn’t add `nowait` keyword to spec then anyone should to remove 
> it (i.e. babel transpiling for example). I wanted that it was part spec. 
> And `nobreak` also is good proposes.
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Re: Re: Proposal to add keyword "nowait"

[Александр Ефремов]

Sorry, I didn’t read it yet. But will be later of course. And I understood 
about actual proposal. Thanks.
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Re: Re: Proposal to add keyword "nowait"

[T.J. Crowder]

@Александр Ефремов -

Have you read through the previous discussion I linked?
https://esdiscuss.org/topic/async-await-await-async-a-simpler-less-error-prone-async-syntax

It seems to me it's exactly what you're describing (other than the keywords
involved). Not sure there's much to gain from re-discussing it (as opposed
to moving forward with an actual proposal).

-- T.J. Crowder
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Re: Re: Proposal to add keyword "nowait"

[Александр Ефремов]

Maybe it should be separate safely mode (similar to `use strict;` for example). 
Where should includes such proposes and maybe more.
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Re: Re: Proposal to add keyword "nowait"

[Александр Ефремов]

I don’t understand how you offer to decide it via eslint. Because without 
additional keyword (`nowait`) it’s impossible to controlling. But if doesn’t 
add `nowait` keyword to spec then anyone should to remove it (i.e. babel 
transpiling for example). I wanted that it was part spec. And `nobreak` also is 
good proposes.
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Re: Proposal to add keyword "nowait"

[Alan Plum]

It sounds like what you want is basically a built-in syntax requirement that 
replaces what should be an eslint rule. For consistency this would mean JS 
should also have the keyword `nobreak` to prevent accidental switch/case 
fallthrough. Or you could just write an eslint rule for this (if one doesn't 
already exist).

On Mon, Feb 12, 2018, at 6:51 AM, Александр Ефремов wrote:
> Yes, agree that it doesn't backwards compatible. But type checking 
> systems (like typescript and flow) it's overhead for fast development.
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Re: Proposal to add keyword "nowait"

[Александр Ефремов]

I just considered this proposal in a context of `node.js` environment. I write 
microservices which execute requests to database and other microservices. All 
such requests are asynchronous. Therefore I execute them in body of async 
function. And sometimes I forget to add `await` for such operations. I thought 
that possible to implement that only for `async await` and didn't know that it 
transpiling to promises queue. I right understand that general problem in that?


> 12 февр. 2018 г., в 11:16, Александр Ефремов  написал(а):
> 
> Yes, I was mistaken. That is possible only to do via type checking systems. 
> it's not work of javascript of the interpreter. Thanks for explanations.
> 
>> 12 февр. 2018 г., в 10:32, T.J. Crowder > > написал(а):
>> 
>> Previous discussion:
>> https://esdiscuss.org/topic/async-await-await-async-a-simpler-less-error-prone-async-syntax
>>  
>> 
>> 
>> -- T.J. Crowder
>> 
>> On Mon, Feb 12, 2018 at 6:29 AM, Александр Ефремов > > wrote:
>> Sorry, but I didn’t understand you sentence. And I have knowledge in the 
>> promises of course.
>> 
>>> 12 февр. 2018 г., в 9:59, Isiah Meadows >> > написал(а):
>>> 
>>> Yeah, and given it's the default, I'm not persuaded of the benefit to be 
>>> gained here.
>>> 
>>> (Most feature requests like these in my experience come from such users who 
>>> use `async`/`await` without learning promises first. Without that 
>>> knowledge, people typically don't get that it's merely syntax sugar for the 
>>> common case, and they rarely understand that `async`/`await` is not 
>>> obligatory to use async functions. When users realize that, this really 
>>> does begin to seem superfluous, since the absence of a keyword or 
>>> `.then`/`.catch` implies you're not awaiting.)
>>> 
>>> 
>>> On Mon, Feb 12, 2018, 00:44 Peter Jaszkowiak >> > wrote:
>>> This certainly doesn't sound backwards compatible. Also, this is something 
>>> that type checking systems (like typescript and flow) are very good at 
>>> catching. 
>>> 
>>> On Feb 11, 2018 22:41, "Александр Ефремов" >> > wrote:
>>> Sometimes when create the async functions forget to add await and later 
>>> such mistake difficult to find.
>>> Maybe would be better always demand to add keyword nowait to calls 
>>> returning promises which we don't plan to wait. But if this keyword and 
>>> await keyword no exists then throw the error.
>>> 
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>> 
>> 
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Re: Proposal to add keyword "nowait"

[Александр Ефремов]

Yes, I was mistaken. That is possible only to do via type checking systems. 
it's not work of javascript of the interpreter. Thanks for explanations.

> 12 февр. 2018 г., в 10:32, T.J. Crowder  
> написал(а):
> 
> Previous discussion:
> https://esdiscuss.org/topic/async-await-await-async-a-simpler-less-error-prone-async-syntax
>  
> 
> 
> -- T.J. Crowder
> 
> On Mon, Feb 12, 2018 at 6:29 AM, Александр Ефремов  > wrote:
> Sorry, but I didn’t understand you sentence. And I have knowledge in the 
> promises of course.
> 
>> 12 февр. 2018 г., в 9:59, Isiah Meadows > > написал(а):
>> 
>> Yeah, and given it's the default, I'm not persuaded of the benefit to be 
>> gained here.
>> 
>> (Most feature requests like these in my experience come from such users who 
>> use `async`/`await` without learning promises first. Without that knowledge, 
>> people typically don't get that it's merely syntax sugar for the common 
>> case, and they rarely understand that `async`/`await` is not obligatory to 
>> use async functions. When users realize that, this really does begin to seem 
>> superfluous, since the absence of a keyword or `.then`/`.catch` implies 
>> you're not awaiting.)
>> 
>> 
>> On Mon, Feb 12, 2018, 00:44 Peter Jaszkowiak > > wrote:
>> This certainly doesn't sound backwards compatible. Also, this is something 
>> that type checking systems (like typescript and flow) are very good at 
>> catching. 
>> 
>> On Feb 11, 2018 22:41, "Александр Ефремов" > > wrote:
>> Sometimes when create the async functions forget to add await and later such 
>> mistake difficult to find.
>> Maybe would be better always demand to add keyword nowait to calls returning 
>> promises which we don't plan to wait. But if this keyword and await keyword 
>> no exists then throw the error.
>> 
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Re: Proposal to add keyword "nowait"

[T.J. Crowder]

Previous discussion:
https://esdiscuss.org/topic/async-await-await-async-a-simpler-less-error-prone-async-syntax

-- T.J. Crowder

On Mon, Feb 12, 2018 at 6:29 AM, Александр Ефремов 
wrote:

> Sorry, but I didn’t understand you sentence. And I have knowledge in the
> promises of course.
>
> 12 февр. 2018 г., в 9:59, Isiah Meadows 
> написал(а):
>
> Yeah, and given it's the default, I'm not persuaded of the benefit to be
> gained here.
>
> (Most feature requests like these in my experience come from such users
> who use `async`/`await` without learning promises first. Without that
> knowledge, people typically don't get that it's merely syntax sugar for the
> common case, and they rarely understand that `async`/`await` is not
> obligatory to use async functions. When users realize that, this really
> does begin to seem superfluous, since the absence of a keyword or
> `.then`/`.catch` implies you're not awaiting.)
>
> On Mon, Feb 12, 2018, 00:44 Peter Jaszkowiak  wrote:
>
>> This certainly doesn't sound backwards compatible. Also, this is
>> something that type checking systems (like typescript and flow) are very
>> good at catching.
>>
>> On Feb 11, 2018 22:41, "Александр Ефремов"  wrote:
>>
>>> Sometimes when create the async functions forget to add await and later
>>> such mistake difficult to find.
>>> Maybe would be better always demand to add keyword nowait to calls
>>> returning promises which we don't plan to wait. But if this keyword and
>>> await keyword no exists then throw the error.
>>>
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Re: Proposal to add keyword "nowait"

[Александр Ефремов]

Sorry, but I didn’t understand you sentence. And I have knowledge in the 
promises of course.

> 12 февр. 2018 г., в 9:59, Isiah Meadows  написал(а):
> 
> Yeah, and given it's the default, I'm not persuaded of the benefit to be 
> gained here.
> 
> (Most feature requests like these in my experience come from such users who 
> use `async`/`await` without learning promises first. Without that knowledge, 
> people typically don't get that it's merely syntax sugar for the common case, 
> and they rarely understand that `async`/`await` is not obligatory to use 
> async functions. When users realize that, this really does begin to seem 
> superfluous, since the absence of a keyword or `.then`/`.catch` implies 
> you're not awaiting.)
> 
> 
> On Mon, Feb 12, 2018, 00:44 Peter Jaszkowiak  > wrote:
> This certainly doesn't sound backwards compatible. Also, this is something 
> that type checking systems (like typescript and flow) are very good at 
> catching. 
> 
> On Feb 11, 2018 22:41, "Александр Ефремов"  > wrote:
> Sometimes when create the async functions forget to add await and later such 
> mistake difficult to find.
> Maybe would be better always demand to add keyword nowait to calls returning 
> promises which we don't plan to wait. But if this keyword and await keyword 
> no exists then throw the error.
> 
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Re: Proposal to add keyword "nowait"

[Isiah Meadows]

Yeah, and given it's the default, I'm not persuaded of the benefit to be
gained here.

(Most feature requests like these in my experience come from such users who
use `async`/`await` without learning promises first. Without that
knowledge, people typically don't get that it's merely syntax sugar for the
common case, and they rarely understand that `async`/`await` is not
obligatory to use async functions. When users realize that, this really
does begin to seem superfluous, since the absence of a keyword or
`.then`/`.catch` implies you're not awaiting.)

On Mon, Feb 12, 2018, 00:44 Peter Jaszkowiak  wrote:

> This certainly doesn't sound backwards compatible. Also, this is something
> that type checking systems (like typescript and flow) are very good at
> catching.
>
> On Feb 11, 2018 22:41, "Александр Ефремов"  wrote:
>
>> Sometimes when create the async functions forget to add await and later
>> such mistake difficult to find.
>> Maybe would be better always demand to add keyword nowait to calls
>> returning promises which we don't plan to wait. But if this keyword and
>> await keyword no exists then throw the error.
>>
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Re: Re: Proposal to add keyword "nowait"

[Александр Ефремов]

Yes, agree that it doesn't backwards compatible. But type checking systems 
(like typescript and flow) it's overhead for fast development.
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Re: Proposal to add keyword "nowait"

[Peter Jaszkowiak]

This certainly doesn't sound backwards compatible. Also, this is something
that type checking systems (like typescript and flow) are very good at
catching.

On Feb 11, 2018 22:41, "Александр Ефремов"  wrote:

> Sometimes when create the async functions forget to add await and later
> such mistake difficult to find.
> Maybe would be better always demand to add keyword nowait to calls
> returning promises which we don't plan to wait. But if this keyword and
> await keyword no exists then throw the error.
>
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