Replace retry with exponential backoff with arrow schedule

[Pururun]

Also clean up the code related to play purchase verification

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This change is 

[linear]

DROID-1014 Add schedulers from Arrow instead of using our own retry function

[albin-mullvad]

Reviewed 14 of 15 files at r1, all commit messages.
Reviewable status: 14 of 15 files reviewed, 2 unresolved discussions (waiting on @Pururun)

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android/app/src/main/kotlin/net/mullvad/mullvadvpn/usecase/PaymentUseCase.kt line 61 at r1 (raw file):

    }

    override suspend fun verifyPurchases() =

It's a bit difficult to interpret what this boolean means in respect to verifyPurchases. true could for example potentially mean that "everything has already been verified".

Also, I'm a bit curious to hear your thoughts on whether or not we could expose the result as an either 🤔

Code quote:

verifyPurchases

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android/lib/payment/build.gradle.kts line 44 at r1 (raw file):

    implementation(Dependencies.Kotlin.stdlib)
    implementation(Dependencies.KotlinX.coroutinesAndroid)
    implementation(Dependencies.Arrow.core)

nit: move to the top of the dependency list

Code quote:

implementation(Dependencies.Arrow.core)

[Pururun]

Reviewable status: 8 of 15 files reviewed, 1 unresolved discussion (waiting on @albin-mullvad)

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android/app/src/main/kotlin/net/mullvad/mullvadvpn/usecase/PaymentUseCase.kt line 61 at r1 (raw file):

Previously, albin-mullvad wrote…

It's a bit difficult to interpret what this boolean means in respect to verifyPurchases. true could for example potentially mean that "everything has already been verified".

Also, I'm a bit curious to hear your thoughts on whether or not we could expose the result as an either 🤔

I guess it depends if you want to add getOrNull() == VerificationResult.Success to all viewmodels or not.
Updated.

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android/lib/payment/build.gradle.kts line 44 at r1 (raw file):

Previously, albin-mullvad wrote…

nit: move to the top of the dependency list

Done

[albin-mullvad]

Reviewed 1 of 15 files at r1, 5 of 6 files at r2, 3 of 3 files at r3, all commit messages.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @Pururun)

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android/app/src/main/kotlin/net/mullvad/mullvadvpn/usecase/PaymentUseCase.kt line 61 at r1 (raw file):

Previously, Pururun (Jonatan Rhodin) wrote…

I guess it depends if you want to add getOrNull() == VerificationResult.Success to all viewmodels or not.
Updated.

Yeah, I think it's best to prioritze keeping the main API clear even though it might require the rest of the code to be a bit more verbose.

Maybe there's some arrow/either API that can be used to make the VMs prettier? Otherwise we can always consider using some extension function such as:

fun Either<VerificationError, VerificationResult>.isSuccess() =
        this.getOrNull() == VerificationResult.Success

Which would let the VMs use:

paymentUseCase.verifyPurchases().isSuccess()

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android/lib/billing/src/main/kotlin/net/mullvad/mullvadvpn/lib/billing/BillingPaymentRepository.kt line 136 at r3 (raw file):

    }

    override suspend fun verifyPurchases(): Either<VerificationError, VerificationResult> = either {

How will the lack of emitting FetchingUnfinishedPurchases and VerificationStarted here impact the code and app behavior? 🤔

[Pururun]

Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @albin-mullvad)

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android/app/src/main/kotlin/net/mullvad/mullvadvpn/usecase/PaymentUseCase.kt line 61 at r1 (raw file):

Previously, albin-mullvad wrote…

Yeah, I think it's best to prioritze keeping the main API clear even though it might require the rest of the code to be a bit more verbose.

Maybe there's some arrow/either API that can be used to make the VMs prettier? Otherwise we can always consider using some extension function such as:

fun Either<VerificationError, VerificationResult>.isSuccess() =
        this.getOrNull() == VerificationResult.Success

Which would let the VMs use:

paymentUseCase.verifyPurchases().isSuccess()

Yes that would look better.

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android/lib/billing/src/main/kotlin/net/mullvad/mullvadvpn/lib/billing/BillingPaymentRepository.kt line 136 at r3 (raw file):

Previously, albin-mullvad wrote…

How will the lack of emitting FetchingUnfinishedPurchases and VerificationStarted here impact the code and app behavior? 🤔

No impact at all. The fact that it was a flow that emitted states before was kind of redundant since we only checked for success state and error states.

[albin-mullvad]

Reviewable status: complete! all files reviewed, all discussions resolved

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android/app/src/main/kotlin/net/mullvad/mullvadvpn/usecase/PaymentUseCase.kt line 61 at r1 (raw file):

Previously, Pururun (Jonatan Rhodin) wrote…

Yes that would look better.

So that means you'll update the PR? I'm fine with either keeping as-is or updating 🙂

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android/lib/billing/src/main/kotlin/net/mullvad/mullvadvpn/lib/billing/BillingPaymentRepository.kt line 136 at r3 (raw file):

Previously, Pururun (Jonatan Rhodin) wrote…

No impact at all. The fact that it was a flow that emitted states before was kind of redundant since we only checked for success state and error states.

Alright 👍

[Pururun]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @albin-mullvad)

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android/app/src/main/kotlin/net/mullvad/mullvadvpn/usecase/PaymentUseCase.kt line 61 at r1 (raw file):

Previously, albin-mullvad wrote…

So that means you'll update the PR? I'm fine with either keeping as-is or updating 🙂

Yes sorry, will add it.

[Pururun]

Reviewable status: 10 of 16 files reviewed, all discussions resolved (waiting on @albin-mullvad)

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android/app/src/main/kotlin/net/mullvad/mullvadvpn/usecase/PaymentUseCase.kt line 61 at r1 (raw file):

Previously, Pururun (Jonatan Rhodin) wrote…

Yes sorry, will add it.

Done

[albin-mullvad]

Reviewed 6 of 6 files at r4, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved

[albin-mullvad]

Reviewed 1 of 1 files at r5, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved

[albin-mullvad]

Reviewed 2 of 2 files at r6, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved