Fixes#2388
Previously `#[tokio::test]` would error on functions that took
arguments. That meant other attribute macros couldn't do further
transformations on them. This changes that so arguments are forwarded as
is.
Whatever else might be included on the function is forwarded as well.
For example return type, generics, etc.
Worth noting that this is only for compatibility with other macros.
`#[test]`s that take arguments will still fail to compile.
A bit odd that [trybuild] tests don't fail `#[test]` functions with
arguments which is why the new tests are run with `t.pass(...)`. They do
actually fail if part of a real crate.
[trybuild]: https://crates.io/crates/trybuild
Improves a few of the error messages for `#[tokio::main]` and `#[tokio::test]`.
Also adds a note to the docs about `start_paused` requiring the `test-util` feature which wasn't mentioned previously.
The time driver stores an Instant internally used as a "base" for future
time calculations. Since this is generated as the Runtime is being
constructed, it previously always happened before the user had a chance
to pause time. The fractional-millisecond variations in the timing
around the runtime construction and time pause cause tests running
entirely in paused time to be very slightly deterministic, with the time
driver advancing time by 1 millisecond more or less depending on how the
sub-millisecond components of the `Instant`s involved compared.
To avoid this, there is now a new option on `runtime::Builder` which
will create a `Runtime` with time "instantly" paused. This, along with a
small change to have the time driver use the provided clock as the
source for its start time allow totally deterministic tests with paused
time.
## Motivation
Looks like the Rust 1.48.0 version of `rustfmt` changed some formatting
rules (fixed some bugs?), and some of the code in `tokio-macros` is no
longer correctly formatted. This is breaking CI.
## Solution
This commit runs rustfmt on Rust 1.48.0. This fixes CI.
Closes#3158
`tokio::test` and related macros now use the absolute path
`::core::prelude::v1::test` to refer to the built-in `test` macro.
This absolute path was introduced in rust-lang/rust#62086.
This is a workaround for the fact that the doc(cfg) from outer cfg_*
macros doesn't get applied correctly. Its included in the rt-threaded
branch only, which is what is used for doc.rs via all-features.
When using #[tokio::main] on a function with generics, the generics are
skipped. Simply using #vis #sig instead of #vis fn #name(#inputs) #ret
fixes the problem.
Fixes#2176
Provides a `select!` macro for concurrently waiting on multiple async
expressions. The macro has similar goals and syntax as the one provided
by the `futures` crate, but differs significantly in implementation.
First, this implementation does not require special traits to be
implemented on futures or streams (i.e., no `FuseFuture`). A design goal
is to be able to pass a "plain" async fn result into the select! macro.
Even without `FuseFuture`, this `select!` implementation is able to
handle all cases the `futures::select!` macro can handle. It does this
by supporting pre-poll conditions on branches and result pattern
matching. For pre-conditions, each branch is able to include a condition
that disables the branch if it evaluates to false. This allows the user
to guard futures that have already been polled, preventing double
polling. Pattern matching can be used to disable streams that complete.
A second big difference is the macro is implemented almost entirely as a
declarative macro. The biggest advantage to using this strategy is that
the user will not need to alter the rustc recursion limit except in the
most extreme cases.
The resulting future also tends to be smaller in many cases.
