Run integrity_test in Externalities (#14546)

* Run integrity_test in RO externalities

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* frame-support: Export RO externalities

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Fix bench tests

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update docs

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Rename to __private

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Run in TestExternalities

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Fix other pallets

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update docs

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Fixes

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update frame/support/src/dispatch.rs

Co-authored-by: Muharem Ismailov <ismailov.m.h@gmail.com>

* Fixup merge

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: parity-processbot <>
Co-authored-by: Muharem Ismailov <ismailov.m.h@gmail.com>

substrate/frame/support/src/traits/hooks.rs

@@ -401,8 +401,8 @@ pub trait Hooks<BlockNumber> {
 	/// `type Bar: Get<u32>` where `Foo::get()` must always be greater than `Bar::get()`, such
 	/// checks can be asserted upon here.
 	///
-	/// Note that this hook is not executed in an externality environment, so if access to state is
-	/// needed, the code should be wrapped in `sp_io::TestExternalities`.
+	/// Note that this hook is executed in an externality environment, provided by
+	/// `sp_io::TestExternalities`. This makes it possible to access the storage.
 	fn integrity_test() {}
 }