Use tokio instead of async-std (#495)

* examples: Use tokio instead of std async

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* test-runtime: Use tokio instead of std async

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* subxt: Use tokio instead of std async

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* examples: Use only necessary tokio features

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

subxt/tests/integration/frame/balances.rs

@@ -36,7 +36,7 @@ use sp_runtime::{
 };
 use subxt::Error;
 
-#[async_std::test]
+#[tokio::test]
 async fn tx_basic_transfer() -> Result<(), subxt::Error<DispatchError>> {
     let alice = pair_signer(AccountKeyring::Alice.pair());
     let bob = pair_signer(AccountKeyring::Bob.pair());
@@ -95,7 +95,7 @@ async fn tx_basic_transfer() -> Result<(), subxt::Error<DispatchError>> {
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn multiple_transfers_work_nonce_incremented(
 ) -> Result<(), subxt::Error<DispatchError>> {
     let alice = pair_signer(AccountKeyring::Alice.pair());
@@ -133,7 +133,7 @@ async fn multiple_transfers_work_nonce_incremented(
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn storage_total_issuance() {
     let cxt = test_context().await;
     let total_issuance = cxt
@@ -146,7 +146,7 @@ async fn storage_total_issuance() {
     assert_ne!(total_issuance, 0);
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn storage_balance_lock() -> Result<(), subxt::Error<DispatchError>> {
     let bob = pair_signer(AccountKeyring::Bob.pair());
     let charlie = AccountKeyring::Charlie.to_account_id();
@@ -187,7 +187,7 @@ async fn storage_balance_lock() -> Result<(), subxt::Error<DispatchError>> {
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn transfer_error() {
     env_logger::try_init().ok();
     let alice = pair_signer(AccountKeyring::Alice.pair());
@@ -226,7 +226,7 @@ async fn transfer_error() {
     }
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn transfer_implicit_subscription() {
     env_logger::try_init().ok();
     let alice = pair_signer(AccountKeyring::Alice.pair());
@@ -259,7 +259,7 @@ async fn transfer_implicit_subscription() {
     );
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn constant_existential_deposit() {
     let cxt = test_context().await;
     let balances_metadata = cxt.client().metadata().pallet("Balances").unwrap();

subxt/tests/integration/frame/contracts.rs

@@ -170,7 +170,7 @@ impl ContractsTestContext {
     }
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn tx_instantiate_with_code() {
     let ctx = ContractsTestContext::init().await;
     let result = ctx.instantiate_with_code().await;
@@ -182,7 +182,7 @@ async fn tx_instantiate_with_code() {
     );
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn tx_instantiate() {
     let ctx = ContractsTestContext::init().await;
     let (code_hash, _) = ctx.instantiate_with_code().await.unwrap();
@@ -196,7 +196,7 @@ async fn tx_instantiate() {
     );
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn tx_call() {
     let cxt = ContractsTestContext::init().await;
     let (_, contract) = cxt.instantiate_with_code().await.unwrap();

subxt/tests/integration/frame/staking.rs

@@ -47,7 +47,7 @@ fn default_validator_prefs() -> ValidatorPrefs {
     }
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn validate_with_controller_account() {
     let alice = pair_signer(AccountKeyring::Alice.pair());
     let ctx = test_context().await;
@@ -63,7 +63,7 @@ async fn validate_with_controller_account() {
         .expect("should be successful");
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn validate_not_possible_for_stash_account() -> Result<(), Error<DispatchError>> {
     let alice_stash = pair_signer(get_from_seed("Alice//stash"));
     let ctx = test_context().await;
@@ -83,7 +83,7 @@ async fn validate_not_possible_for_stash_account() -> Result<(), Error<DispatchE
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn nominate_with_controller_account() {
     let alice = pair_signer(AccountKeyring::Alice.pair());
     let bob = pair_signer(AccountKeyring::Bob.pair());
@@ -101,7 +101,7 @@ async fn nominate_with_controller_account() {
         .expect("should be successful");
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn nominate_not_possible_for_stash_account() -> Result<(), Error<DispatchError>> {
     let alice_stash = pair_signer(get_from_seed("Alice//stash"));
     let bob = pair_signer(AccountKeyring::Bob.pair());
@@ -124,7 +124,7 @@ async fn nominate_not_possible_for_stash_account() -> Result<(), Error<DispatchE
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn chill_works_for_controller_only() -> Result<(), Error<DispatchError>> {
     let alice_stash = pair_signer(get_from_seed("Alice//stash"));
     let bob_stash = pair_signer(get_from_seed("Bob//stash"));
@@ -180,7 +180,7 @@ async fn chill_works_for_controller_only() -> Result<(), Error<DispatchError>> {
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn tx_bond() -> Result<(), Error<DispatchError>> {
     let alice = pair_signer(AccountKeyring::Alice.pair());
     let ctx = test_context().await;
@@ -222,7 +222,7 @@ async fn tx_bond() -> Result<(), Error<DispatchError>> {
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn storage_history_depth() -> Result<(), Error<DispatchError>> {
     let ctx = test_context().await;
     let history_depth = ctx.api.storage().staking().history_depth(None).await?;
@@ -230,7 +230,7 @@ async fn storage_history_depth() -> Result<(), Error<DispatchError>> {
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn storage_current_era() -> Result<(), Error<DispatchError>> {
     let ctx = test_context().await;
     let _current_era = ctx
@@ -243,7 +243,7 @@ async fn storage_current_era() -> Result<(), Error<DispatchError>> {
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn storage_era_reward_points() -> Result<(), Error<DispatchError>> {
     let cxt = test_context().await;
     let current_era_result = cxt

subxt/tests/integration/frame/sudo.rs

@@ -28,7 +28,7 @@ use sp_keyring::AccountKeyring;
 type Call = runtime_types::node_runtime::Call;
 type BalancesCall = runtime_types::pallet_balances::pallet::Call;
 
-#[async_std::test]
+#[tokio::test]
 async fn test_sudo() -> Result<(), subxt::Error<DispatchError>> {
     let alice = pair_signer(AccountKeyring::Alice.pair());
     let bob = AccountKeyring::Bob.to_account_id().into();
@@ -54,7 +54,7 @@ async fn test_sudo() -> Result<(), subxt::Error<DispatchError>> {
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn test_sudo_unchecked_weight() -> Result<(), subxt::Error<DispatchError>> {
     let alice = pair_signer(AccountKeyring::Alice.pair());
     let bob = AccountKeyring::Bob.to_account_id().into();

subxt/tests/integration/frame/system.rs

@@ -25,7 +25,7 @@ use crate::{
 use assert_matches::assert_matches;
 use sp_keyring::AccountKeyring;
 
-#[async_std::test]
+#[tokio::test]
 async fn storage_account() -> Result<(), subxt::Error<DispatchError>> {
     let alice = pair_signer(AccountKeyring::Alice.pair());
 
@@ -41,7 +41,7 @@ async fn storage_account() -> Result<(), subxt::Error<DispatchError>> {
     Ok(())
 }
 
-#[async_std::test]
+#[tokio::test]
 async fn tx_remark_with_event() -> Result<(), subxt::Error<DispatchError>> {
     let alice = pair_signer(AccountKeyring::Alice.pair());
     let cxt = test_context().await;

subxt/tests/integration/frame/timestamp.rs

@@ -16,7 +16,7 @@
 
 use crate::test_context;
 
-#[async_std::test]
+#[tokio::test]
 async fn storage_get_current_timestamp() {
     let cxt = test_context().await;