Add async test helper to timeout and provide a task_executor automatically (#6651)

* Initial commit

Forked at: 74655edebc
Parent branch: origin/master

* Add async test helper to timeout and provide a task_executor automatically

* simplify error message to avoid difference between CI and locally

* forgot env var

* Use runtime env var instead of build env var

* Rename variable to SUBSTRATE_TEST_TIMEOUT

* CLEANUP

Forked at: 74655edebc
Parent branch: origin/master

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Re-export from test-utils

* Default value to 120

* fix wrong crate in ci

* Revert "Default value to 120"

This reverts commit 8e458717078b242ffce7d3c4f66241d76f075125.

* Fix version

* WIP

Forked at: 74655edebc
Parent branch: origin/master

* WIP

Forked at: 74655edebc
Parent branch: origin/master

* WIP

Forked at: 74655edebc
Parent branch: origin/master

* remove feature flag

* fix missing dependency

* CLEANUP

Forked at: 74655edebc
Parent branch: origin/master

* fix test

* Removed autotests=false

* Some doc...

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* WIP

Forked at: 74655edebc
Parent branch: origin/master

* WIP

Forked at: 74655edebc
Parent branch: origin/master

* Update test-utils/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/test-utils/src/lib.rs

@@ -17,6 +17,29 @@
 
 //! Test utils
 
+#[doc(hidden)]
+pub use futures;
+/// Marks async function to be executed by an async runtime and provide a `TaskExecutor`, suitable
+/// to test environment.
+///
+/// # Requirements
+///
+///	You must have tokio in the `[dev-dependencies]` of your crate to use this macro.
+///
+/// # Example
+///
+/// ```
+/// #[substrate_test_utils::test]
+/// async fn basic_test(task_executor: TaskExecutor) {
+///     assert!(true);
+///     // create your node in here and use task_executor
+///     // then don't forget to gracefully shutdown your node before exit
+/// }
+/// ```
+pub use substrate_test_utils_derive::test;
+#[doc(hidden)]
+pub use tokio;
+
 /// Panic when the vectors are different, without taking the order into account.
 ///
 /// # Examples