tokio_test::io::Mock does not read actions from handle when used as writer

[pbrenna]

Version

├── tokio v1.28.2
│   └── tokio-macros v2.1.0 (proc-macro)
└── tokio-test v0.4.2
    ├── tokio v1.28.2 (*)
    └── tokio-stream v0.1.14
        └── tokio v1.28.2 (*)

Platform
Linux lenovo-arch 6.3.8-arch1-1 #1 SMP PREEMPT_DYNAMIC Wed, 14 Jun 2023 20:10:31 +0000 x86_64 GNU/Linux

[dependencies]
tokio = {version = "1.28.2", features = ["macros", "rt-multi-thread", "io-util", "rt"]}
tokio-test = "0.4.2"

Description

use tokio_test::io::Builder;

use tokio::io::{AsyncReadExt, AsyncWriteExt};
#[tokio::main]
async fn main() {
    let mut wr = Builder::new().write(b"hello").build();
    println!("{:?}", AsyncWriteExt::write(&mut wr, b"hello").await);

    let (mut wr, mut wr_h) = Builder::new().build_with_handle();
    wr_h.write(b"hello");
    println!("{:?}", AsyncWriteExt::write(&mut wr, b"hello").await);

    let (mut wr, mut wr_h) = Builder::new().build_with_handle();
    wr_h.read(b"world");
    let mut buf = vec![0; 8];
    println!("{:?}", AsyncReadExt::read(&mut wr, &mut buf).await);
}

Expected output:

Ok(5)
Ok(5)
Ok(5)

Actual output:

Ok(5)
Err(Kind(BrokenPipe))
Ok(5)

Additional notes

tokio/tokio-test/src/io.rs

Lines 422 to 425 in 2e62374

	// TODO: Is this correct?
	if !self.inner.actions.is_empty() {
	return Poll::Pending;
	}

I suspect this is not correct
EDIT: I suspect instead that this is fine, but self.inner.poll_action should be called before self.inner.write. Working on PR.