New Event Subscription API (#442)

* Add reworked event types

* first pass implementing event subscriptions

* make clear that some methods are private

* comment tidy

* use Events in transaction stuff

* align transaction and event APIs

* remove __private_ prefixes; they are ugly

* fix examples and remove old events and subscription code

* better comments on hidden event functions

* re-add find_first_event; it's used a bunch in tests and examples

* cargo check --all-targets now passes

* Fix up existing event tests

* cargo fmt

* change todo to note

* clippy and doc niggles

* revert to find_first_event

* Add specific subscription related tests

* cargo fmt

* Update tests and add/fix examples

* cargo fmt

* add a little to subscribe_all_events example

* cargo fmt

* move an example comment

* easy access to root mod for more clarity

* add a couple of tests to ensure that events properly decoded until naff bytes

* Simplify EventSubscription Stream impl a little

* Address some PR feedback

subxt/tests/integration/frame/balances.rs

@@ -31,9 +31,7 @@ use sp_core::{
 };
 use sp_keyring::AccountKeyring;
 use subxt::{
-    DefaultConfig,
     Error,
-    EventSubscription,
     Signer,
 };
 
@@ -189,38 +187,6 @@ async fn transfer_error() {
     }
 }
 
-#[async_std::test]
-async fn transfer_subscription() {
-    env_logger::try_init().ok();
-    let alice = pair_signer(AccountKeyring::Alice.pair());
-    let bob = AccountKeyring::Bob.to_account_id();
-    let bob_addr = bob.clone().into();
-    let cxt = test_context().await;
-    let sub = cxt.client().rpc().subscribe_events().await.unwrap();
-    let decoder = cxt.client().events_decoder();
-    let mut sub = EventSubscription::<DefaultConfig>::new(sub, decoder);
-    sub.filter_event::<balances::events::Transfer>();
-
-    cxt.api
-        .tx()
-        .balances()
-        .transfer(bob_addr, 10_000)
-        .sign_and_submit_then_watch(&alice)
-        .await
-        .unwrap();
-
-    let raw = sub.next().await.unwrap().unwrap();
-    let event = balances::events::Transfer::decode(&mut &raw.data[..]).unwrap();
-    assert_eq!(
-        event,
-        balances::events::Transfer {
-            from: alice.account_id().clone(),
-            to: bob.clone(),
-            amount: 10_000
-        }
-    );
-}
-
 #[async_std::test]
 async fn transfer_implicit_subscription() {
     env_logger::try_init().ok();

subxt/tests/integration/frame/contracts.rs

@@ -18,6 +18,7 @@ use sp_keyring::AccountKeyring;
 
 use crate::{
     node_runtime::{
+        self,
         contracts::{
             calls::TransactionApi,
             events,
@@ -150,8 +151,10 @@ impl ContractsTestContext {
         &self,
         contract: AccountId,
         input_data: Vec<u8>,
-    ) -> Result<TransactionProgress<'_, DefaultConfig, DispatchError>, Error<DispatchError>>
-    {
+    ) -> Result<
+        TransactionProgress<'_, DefaultConfig, DispatchError, node_runtime::Event>,
+        Error<DispatchError>,
+    > {
         log::info!("call: {:?}", contract);
         let result = self
             .contracts_tx()

subxt/tests/integration/frame/staking.rs

@@ -180,7 +180,7 @@ async fn chill_works_for_controller_only() -> Result<(), Error<DispatchError>> {
         .await?
         .wait_for_finalized_success()
         .await?
-        .has_event::<staking::events::Chilled>()?;
+        .has::<staking::events::Chilled>()?;
     assert!(is_chilled);
 
     Ok(())

subxt/tests/integration/frame/sudo.rs

@@ -48,7 +48,7 @@ async fn test_sudo() -> Result<(), subxt::Error<DispatchError>> {
         .await?
         .wait_for_finalized_success()
         .await?
-        .has_event::<sudo::events::Sudid>()?;
+        .has::<sudo::events::Sudid>()?;
 
     assert!(found_event);
     Ok(())
@@ -74,7 +74,7 @@ async fn test_sudo_unchecked_weight() -> Result<(), subxt::Error<DispatchError>>
         .await?
         .wait_for_finalized_success()
         .await?
-        .has_event::<sudo::events::Sudid>()?;
+        .has::<sudo::events::Sudid>()?;
 
     assert!(found_event);
     Ok(())

subxt/tests/integration/frame/system.rs

@@ -56,7 +56,7 @@ async fn tx_remark_with_event() -> Result<(), subxt::Error<DispatchError>> {
         .await?
         .wait_for_finalized_success()
         .await?
-        .has_event::<system::events::Remarked>()?;
+        .has::<system::events::Remarked>()?;
 
     assert!(found_event);
     Ok(())