feat: Add async/await wrappers

[cbaker6]

New Pull Request Checklist

• I am not disclosing a vulnerability.
• I am creating this PR in reference to an issue.

Issue Description

Add all necessary async/await wrappers. Requires Xcode 13 beta and Swift 5.5.

Developers wanting to use async/await should point their SPM to this branch.

Related issue: #234

Approach

Add async/await using wrappers around async completion methods.

TODOs before merging

• add async/await for all ParseObject variants and other types
• add async/await for ParseAuthentication types
• bump CI to Xcode 13
• update documentation for async/await
• add test cases
• add change log entry
• wait for codecov.io to support Xcode 13 codecov Letting codecov slip for now since codecov.io can't read Xcode 13 xcrun llvm-cov properly. The codecov is really at 85%, will rerun when the website can read latest Xcode.

[codecov]

Codecov Report

Merging #212 (577c5d3) into main (97011ac) will decrease coverage by 7.14%.
The diff coverage is 23.86%.

@@            Coverage Diff             @@
##             main     #212      +/-   ##
==========================================
- Coverage   83.83%   76.68%   -7.15%     
==========================================
  Files          80       99      +19     
  Lines        7392    10351    +2959     
==========================================
+ Hits         6197     7938    +1741     
- Misses       1195     2413    +1218     

Impacted Files	Coverage Δ
...cation/3rd Party/ParseApple/ParseApple+async.swift	0.00% <0.00%> (ø)
...thentication/3rd Party/ParseApple/ParseApple.swift	82.50% <ø> (ø)
.../3rd Party/ParseFacebook/ParseFacebook+async.swift	0.00% <0.00%> (ø)
...cation/3rd Party/ParseFacebook/ParseFacebook.swift	100.00% <ø> (ø)
...tication/3rd Party/ParseLDAP/ParseLDAP+async.swift	0.00% <0.00%> (ø)
...Authentication/3rd Party/ParseLDAP/ParseLDAP.swift	100.00% <ø> (ø)
...on/3rd Party/ParseTwitter/ParseTwitter+async.swift	0.00% <0.00%> (ø)
...tication/3rd Party/ParseTwitter/ParseTwitter.swift	100.00% <ø> (ø)
...Authentication/Internal/ParseAnonymous+async.swift	0.00% <0.00%> (ø)
...Swift/Authentication/Internal/ParseAnonymous.swift	100.00% <ø> (ø)
... and 106 more

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[vdkdamian]

@cbaker6 Are SubscriptionCallback's supported? .handleEvent seems to look the same?

[cbaker6]

@cbaker6 Are SubscriptionCallback's supported? .handleEvent seems to look the same?

What would be the use case for using async/await with a subscription callback or with subscriptions for LiveQuery in general?

[vdkdamian]

@cbaker6 Are SubscriptionCallback's supported? .handleEvent seems to look the same?

What would be the use case for using async/await with a subscription callback or with subscriptions for LiveQuery in general?

I notice that I can't run my own async code this way. Is there an alternative approach I am missing?
I call the function like this

let query = NVMFile.query("project" == app.rawValue)
let subscription = query.subscribeCallback!
await handleSynchronisation(subscription: subscription)

[vdkdamian]

@cbaker6 Also another question, what is the correct/best way to compare errors when using async?

I used to check it like this:

let query = NVMFile.query()
query.first() { results in
    switch results {
    case .success(_):
        //Do stuff
    case .failure(let error):
        if error.code == ParseError.Code.objectNotFound {
            //Do stuff
        } else {
            //Do other stuff
        }
    }
}

i thought of something like this, but I doubt it will be good:

do {
    //Stuff
} catch let queryError {
    if let parseError = queryError as? ParseError, parseError.code == ParseError.Code.objectNotFound {
        //Do stuff
    }
    else {
        //Do other stuff
    }
}

[cbaker6]

I suggest reading https://www.avanderlee.com/swift/async-await/#async-methods-call-in-a-function-that-does-not-support-concurrency and https://www.andyibanez.com/posts/understanding-async-await-in-swift/

The rest of that article discusses when and how to use async/await and it's important to note it's not the solution for everything.

[vdkdamian]

@cbaker6 Also another question, what is the correct/best way to compare errors when using async?

I used to check it like this:

let query = NVMFile.query()

query.first() { results in

    switch results {

    case .success(_):

        //Do stuff

    case .failure(let error):

        if error.code == ParseError.Code.objectNotFound {

            //Do stuff

        } else {

            //Do other stuff

        }

    }

}

i thought of something like this, but I doubt it will be good:

do {

    //Stuff

} catch let queryError {

    if let parseError = queryError as? ParseError, parseError.code == ParseError.Code.objectNotFound {

        //Do stuff

    }

    else {

        //Do other stuff

    }

}

@cbaker6

Do you have an idea on how to cleanly compare Errors catched from a trycatch with ParseError?

You think my method is the best, or are there better options?

[cbaker6]

Your process is fine, though you can shrink the code some and handle errors with a switch:

do {

    //try Stuff

} catch {

   guard let parseError = error as? ParseError else {
        //Do stuff for different error
      return
    }

    // Handle ParseError.
   switch parseError.code {
                case .objectNotFound: 
                    // Handle object not found
                default:
                    // There was a different issue that we don't know how to handle
                }

}

You can see similar in my SDK, though it's currently not using async, https://github.com/netreconlab/ParseCareKit/blob/949393ea1e74eb01ef99c165e1966ff4490a0bae/Sources/ParseCareKit/Objects/Patient.swift#L114-L144

[vdkdamian]

@cbaker6 Question, would it be possible to merge 1.10.1 into this branch?

My SPM is set on your async branch, and this way I could test te changes in 1.10.1

If this isn't an option, no problem, but I think it's worth the question.

Thanks in advance!