1851037 - Refactor `LoadUrlUseCase.invoke` to be an operator function

Status: RESOLVED FIXED

(Firefox for Android :: Browser Engine, task)

Description

[Lina Butler (ex-Mozilla)]

The LoadUrlUseCase.invoke method in the feature-session Android Component is declared as a regular fun, not an operator fun. That means we must invoke it explicitly, like this:

loadUrlUseCase.invoke(url)

If we declared invoke as an operator fun, we could invoke it using the more convenient function call syntax instead:

loadUrlUseCase(url)

For this bug, let's:

1. Change the declaration of invoke to use operator fun.
2. Ensure that all implementations of LoadUrlUseCase use override operator fun.
3. Refactor all callers in all components to use the more convenient function call syntax, instead of explicitly calling .invoke().

This is a great first bug for getting started with Android and Kotlin development!

Comment 1

[jackyzy823]

For the point 3:
It may not possible do something like usecase?() in kotlin 1 .

Alternative way

usecase?.let { it() }

IMHO, invoke() looks better .

Link: https://github.com/mozilla-mobile/firefox-android/blob/main/android-components/components/feature/app-links/src/main/java/mozilla/components/feature/app/links/AppLinksFeature.kt#L159

Ref: https://discuss.kotlinlang.org/t/cannot-use-the-invoke-operator-after-a-non-null-check/17830/4
Ref: https://youtrack.jetbrains.com/issue/KT-4113

Comment 2

[Lina Butler (ex-Mozilla)]

Thanks for noting that, and for the links; that's really good to know!

IMHO, invoke() looks better .

I think so, too 😊 Let's leave the nullable calls as usecase?.invoke(), but switch to usecase() for non-nullable calls—how does that sound?

Comment 3

[Andrei Popa]

Attachment: Bug 1851037 - changed fun to operator fun and refactored all callers to avoid explicitly call invoke

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/75c4613ada94
changed fun to operator fun and refactored all callers to avoid explicitly call invoke r=android-reviewers,avirvara

Comment 5

[Atila Butkovits]

Backed out for causing failures at TabsUseCasesTest.kt.

Backout link: https://hg.mozilla.org/integration/autoland/rev/70bdae77d7e8dc621fc05cbc470f2aa7b34e06e2

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=75c4613ada948145580151cea7e1ce0d027348fe&selectedTaskRun=c6h7y-n5S36v00McPqG7iA.0

Failure log: https://treeherder.mozilla.org/logviewer?job_id=481447258&repo=autoland&lineNumber=25380

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a5f9fda9fb3a
changed fun to operator fun and refactored all callers to avoid explicitly call invoke r=android-reviewers,avirvara

Comment 7

[amarc]

https://hg.mozilla.org/mozilla-central/rev/a5f9fda9fb3a