Improve error handling in proc-macros, handle DispatchError etc. (#123)

* Improve error handling.

* Fix build.

* Handle runtime errors.

* Add runtime trait for better type inference.

* Use runtime trait part 1.

* wip

* Add support for sudo.

* Finish error handling.

* Fix tests.

* Fix clippy warnings.

src/frame/balances.rs

@@ -110,36 +110,56 @@ pub struct TransferEvent<T: Balances> {
 mod tests {
     use super::*;
     use crate::{
-        system::{
-            AccountStore,
-            AccountStoreExt,
+        error::{
+            Error,
+            RuntimeError,
         },
-        tests::test_client,
+        signer::{
+            PairSigner,
+            Signer,
+        },
+        system::AccountStoreExt,
+        tests::{
+            test_client,
+            TestRuntime,
+        },
+    };
+    use sp_core::{
+        sr25519::Pair,
+        Pair as _,
     };
     use sp_keyring::AccountKeyring;
 
-    subxt_test!({
-        name: test_transfer,
-        step: {
-            state: {
-                alice: AccountStore { account_id: &alice },
-                bob: AccountStore { account_id: &bob },
-            },
-            call: TransferCall {
-                to: &bob.clone().into(),
-                amount: 10_000,
-            },
-            event: TransferEvent {
-                from: alice.clone(),
-                to: bob.clone(),
-                amount: 10_000,
-            },
-            assert: {
-                assert!(pre.alice.data.free - 10_000 >= post.alice.data.free);
-                assert_eq!(pre.bob.data.free + 10_000, post.bob.data.free);
-            },
-        },
-    });
+    #[async_std::test]
+    async fn test_transfer() {
+        env_logger::try_init().ok();
+        let alice = PairSigner::<TestRuntime, _>::new(AccountKeyring::Alice.pair());
+        let bob = PairSigner::<TestRuntime, _>::new(AccountKeyring::Bob.pair());
+        let (client, _) = test_client().await;
+
+        let alice_pre = client.account(alice.account_id(), None).await.unwrap();
+        let bob_pre = client.account(bob.account_id(), None).await.unwrap();
+
+        let event = client
+            .transfer_and_watch(&alice, &bob.account_id(), 10_000)
+            .await
+            .unwrap()
+            .transfer()
+            .unwrap()
+            .unwrap();
+        let expected_event = TransferEvent {
+            from: alice.account_id().clone(),
+            to: bob.account_id().clone(),
+            amount: 10_000,
+        };
+        assert_eq!(event, expected_event);
+
+        let alice_post = client.account(alice.account_id(), None).await.unwrap();
+        let bob_post = client.account(bob.account_id(), None).await.unwrap();
+
+        assert!(alice_pre.data.free - 10_000 >= alice_post.data.free);
+        assert_eq!(bob_pre.data.free + 10_000, bob_post.data.free);
+    }
 
     #[async_std::test]
     async fn test_state_total_issuance() {
@@ -157,4 +177,28 @@ mod tests {
         let info = client.account(&account, None).await.unwrap();
         assert_ne!(info.data.free, 0);
     }
+
+    #[async_std::test]
+    async fn test_transfer_error() {
+        env_logger::try_init().ok();
+        let alice = PairSigner::new(AccountKeyring::Alice.pair());
+        let hans = PairSigner::new(Pair::generate().0);
+        let (client, _) = test_client().await;
+        client
+            .transfer_and_watch(&alice, hans.account_id(), 100_000_000_000)
+            .await
+            .unwrap();
+        let res = client
+            .transfer_and_watch(&hans, alice.account_id(), 100_000_000_000)
+            .await;
+        if let Err(Error::Runtime(error)) = res {
+            let error2 = RuntimeError {
+                module: "Balances".into(),
+                error: "InsufficientBalance".into(),
+            };
+            assert_eq!(error, error2);
+        } else {
+            panic!("expected an error");
+        }
+    }
 }

src/frame/mod.rs

@@ -31,6 +31,7 @@ use sp_core::storage::StorageKey;
 
 pub mod balances;
 pub mod contracts;
+pub mod sudo;
 pub mod system;
 
 /// Store trait.

src/frame/sudo.rs

@@ -0,0 +1,78 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Implements support for the frame_sudo module.
+
+use crate::{
+    frame::system::{
+        System,
+        SystemEventsDecoder,
+    },
+    Encoded,
+};
+use codec::Encode;
+use core::marker::PhantomData;
+
+/// The subset of the `frame_sudo::Trait` that a client must implement.
+#[module]
+pub trait Sudo: System {}
+
+/// Execute a transaction with sudo permissions.
+#[derive(Clone, Debug, Eq, PartialEq, Call, Encode)]
+pub struct SudoCall<'a, T: Sudo> {
+    /// Runtime marker.
+    pub _runtime: PhantomData<T>,
+    /// Encoded transaction.
+    pub call: &'a Encoded,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{
+        error::Error,
+        frame::balances::TransferCall,
+        signer::PairSigner,
+        tests::{
+            test_client,
+            TestRuntime,
+        },
+    };
+    use sp_keyring::AccountKeyring;
+
+    #[async_std::test]
+    async fn test_sudo() {
+        env_logger::try_init().ok();
+        let alice = PairSigner::<TestRuntime, _>::new(AccountKeyring::Alice.pair());
+        let (client, _) = test_client().await;
+
+        let call = client
+            .encode(TransferCall {
+                to: &AccountKeyring::Bob.to_account_id(),
+                amount: 10_000,
+            })
+            .unwrap();
+
+        let res = client.sudo_and_watch(&alice, &call).await;
+        assert!(
+            if let Err(Error::BadOrigin) = res {
+                true
+            } else {
+                false
+            }
+        );
+    }
+}

src/frame/system.rs

@@ -155,21 +155,6 @@ pub struct SetCodeCall<'a, T: System> {
     pub code: &'a [u8],
 }
 
-/// Event for the System module.
-#[derive(Clone, Debug, Eq, PartialEq, Decode)]
-pub enum SystemEvent<T: System> {
-    /// An extrinsic completed successfully.
-    ExtrinsicSuccess(DispatchInfo),
-    /// An extrinsic failed.
-    ExtrinsicFailed(DispatchError, DispatchInfo),
-    /// `:code` was updated.
-    CodeUpdated,
-    /// A new account was created.
-    NewAccount(T::AccountId),
-    /// An account was reaped.
-    KilledAccount(T::AccountId),
-}
-
 /// A phase of a block's execution.
 #[derive(Clone, Debug, Eq, PartialEq, Decode)]
 pub enum Phase {
@@ -178,3 +163,44 @@ pub enum Phase {
     /// The end.
     Finalization,
 }
+
+/// An extrinsic completed successfully.
+#[derive(Clone, Debug, Eq, PartialEq, Event, Decode)]
+pub struct ExtrinsicSuccessEvent<T: System> {
+    /// Runtime marker.
+    pub _runtime: PhantomData<T>,
+    /// The dispatch info.
+    pub info: DispatchInfo,
+}
+
+/// An extrinsic failed.
+#[derive(Clone, Debug, Eq, PartialEq, Event, Decode)]
+pub struct ExtrinsicFailedEvent<T: System> {
+    /// Runtime marker.
+    pub _runtime: PhantomData<T>,
+    /// The dispatch error.
+    pub error: DispatchError,
+    /// The dispatch info.
+    pub info: DispatchInfo,
+}
+
+/// `:code` was updated.
+#[derive(Clone, Debug, Eq, PartialEq, Event, Decode)]
+pub struct CodeUpdatedEvent<T: System> {
+    /// Runtime marker.
+    pub _runtime: PhantomData<T>,
+}
+
+/// A new account was created.
+#[derive(Clone, Debug, Eq, PartialEq, Event, Decode)]
+pub struct NewAccountEvent<T: System> {
+    /// Created account id.
+    pub account: T::AccountId,
+}
+
+/// An account was reaped.
+#[derive(Clone, Debug, Eq, PartialEq, Event, Decode)]
+pub struct KilledAccountEvent<T: System> {
+    /// Killed account id.
+    pub account: T::AccountId,
+}