Add tests for version checker

[dlon]

Fix DES-870.

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This change is 

[linear]

DES-870 Write tests for version checks

[MarkusPettersson98]

Reviewed 2 of 2 files at r1, 2 of 2 files at r2, 1 of 1 files at r3, 1 of 1 files at r4, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @dlon)

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mullvad-daemon/src/version_check.rs line 622 at r2 (raw file):

    /// Test whether check immediately fetches version info if it's non-existent
    #[tokio::test(start_paused = true)]
    async fn test_version_check_run_immediate() {

If I run cargo test in the mullvad-daemon crate, I get the following error

$ cargo test
   Compiling mullvad-daemon v0.0.0 (/home/markus/projects/mullvad/app/mullvad-daemon)
error[E0599]: no method named `start_paused` found for struct `tokio::runtime::Builder` in the current scope
   --> mullvad-daemon/src/version_check.rs:620:5
    |
620 |     #[tokio::test(start_paused = true)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ private field, not a method
    |
    = note: this error originates in the attribute macro `tokio::test` (in Nightly builds, run with -Z macro-backtrace for more info)

It can be fixed by enabling the test-util feature for tokio

# mullvad-daemon/Cargo.toml
[dev-dependencies]
talpid-time = { path = "../talpid-time", features = ["test"] }
tokio = { workspace = true, features =  ["test-util"] }

Code quote:

    #[tokio::test(start_paused = true)]
    async fn test_version_check_run_immediate() {

[dlon]

Reviewable status: 3 of 4 files reviewed, 1 unresolved discussion (waiting on @MarkusPettersson98)

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mullvad-daemon/src/version_check.rs line 622 at r2 (raw file):

Previously, MarkusPettersson98 (Markus Pettersson) wrote…

If I run cargo test in the mullvad-daemon crate, I get the following error

$ cargo test
   Compiling mullvad-daemon v0.0.0 (/home/markus/projects/mullvad/app/mullvad-daemon)
error[E0599]: no method named `start_paused` found for struct `tokio::runtime::Builder` in the current scope
   --> mullvad-daemon/src/version_check.rs:620:5
    |
620 |     #[tokio::test(start_paused = true)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ private field, not a method
    |
    = note: this error originates in the attribute macro `tokio::test` (in Nightly builds, run with -Z macro-backtrace for more info)

It can be fixed by enabling the test-util feature for tokio

# mullvad-daemon/Cargo.toml
[dev-dependencies]
talpid-time = { path = "../talpid-time", features = ["test"] }
tokio = { workspace = true, features =  ["test-util"] }

Fixed! Thanks.

[MarkusPettersson98]

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

[MarkusPettersson98]

Reviewed 1 of 1 files at r6, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved

[hulthe]

Reviewed 1 of 2 files at r8, 1 of 1 files at r9, all commit messages.
Reviewable status: 3 of 4 files reviewed, 4 unresolved discussions (waiting on @dlon and @MarkusPettersson98)

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mullvad-daemon/src/version_check.rs line 221 at r9 (raw file):

    /// Also, if we are currently have a pending [GetVersionInfo][rvc] command, respond to it.
    ///
    /// [rvc]: VersionUpdaterCommand::GetVersionInfo

This docstr looks outdated

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mullvad-daemon/src/version_check.rs line 401 at r9 (raw file):

impl UpdateContext {
    /// Write [Self::last_app_version_info], if any, to the cache file ([VERSION_INFO_FILENAME]).
    /// Also notify listener

Broken doc link

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mullvad-daemon/src/version_check.rs line 418 at r9 (raw file):

            let _ = tokio::io::copy(&mut read_buf, &mut file)
                .await
                .map_err(Error::WriteVersionCache)?;

Nit: Would tokio::fs::write look nicer?

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mullvad-daemon/src/version_check.rs line 739 at r9 (raw file):

            latest_beta: "2024.1-beta1".to_owned(),
        }
    }

Very cool test setup. Didn't know tokio had these features.

[dlon]

Reviewable status: 3 of 4 files reviewed, 3 unresolved discussions (waiting on @hulthe and @MarkusPettersson98)

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mullvad-daemon/src/version_check.rs line 221 at r9 (raw file):

Previously, hulthe (Joakim Hulthe) wrote…

This docstr looks outdated

Done.

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mullvad-daemon/src/version_check.rs line 401 at r9 (raw file):

Previously, hulthe (Joakim Hulthe) wrote…

Broken doc link

Done.

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mullvad-daemon/src/version_check.rs line 418 at r9 (raw file):

Previously, hulthe (Joakim Hulthe) wrote…

Nit: Would tokio::fs::write look nicer?

It would! Done.

[hulthe]

Reviewed 1 of 1 files at r12, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved

The base branch was changed.

[MarkusPettersson98]

Reviewed 3 of 3 files at r13, 3 of 3 files at r14, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved