From 5b0e6af790ee70b27a2f0fbac0f133f81549ed2d Mon Sep 17 00:00:00 2001
From: David Craven <david@craven.ch>
Date: Tue, 26 May 2020 11:36:01 +0200
Subject: [PATCH] Add support for sudo.

---
 src/frame/mod.rs  |  1 +
 src/frame/sudo.rs | 61 +++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs        | 15 ++++++++----
 src/runtimes.rs   |  3 +++
 4 files changed, 75 insertions(+), 5 deletions(-)
 create mode 100644 src/frame/sudo.rs

diff --git a/src/frame/mod.rs b/src/frame/mod.rs
index 7244b8c35f..1c8e419e0f 100644
--- a/src/frame/mod.rs
+++ b/src/frame/mod.rs
@@ -34,6 +34,7 @@ use sp_core::storage::StorageKey;
 
 pub mod balances;
 pub mod contracts;
+pub mod sudo;
 pub mod system;
 
 /// Store trait.
diff --git a/src/frame/sudo.rs b/src/frame/sudo.rs
new file mode 100644
index 0000000000..cb06d1e05d
--- /dev/null
+++ b/src/frame/sudo.rs
@@ -0,0 +1,61 @@
+// 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::frame::balances::TransferCall;
+
+    subxt_test!({
+        name: test_sudo,
+        step: {
+            call: SudoCall {
+                _runtime: PhantomData,
+                call: &client.encode(
+                    TransferCall {
+                        to: &bob.clone().into(),
+                        amount: 10_000,
+                    }
+                ).unwrap(),
+            },
+        }
+    });
+}
diff --git a/src/lib.rs b/src/lib.rs
index 9d38535627..7a14259f73 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -300,6 +300,14 @@ where
     S: Encode + Send + Sync + 'static,
     E: SignedExtra<T> + SignedExtension + Send + Sync + 'static,
 {
+    /// Encodes a call.
+    pub fn encode<C: Call<T>>(&self, call: C) -> Result<Encoded, Error> {
+        Ok(self
+            .metadata()
+            .module_with_calls(C::MODULE)
+            .and_then(|module| module.call(C::FUNCTION, call))?)
+    }
+
     /// Creates an unsigned extrinsic.
     ///
     /// If `nonce` is `None` the nonce will be fetched from the chain.
@@ -317,10 +325,7 @@ where
         let spec_version = self.runtime_version.spec_version;
         let tx_version = self.runtime_version.transaction_version;
         let genesis_hash = self.genesis_hash;
-        let call = self
-            .metadata()
-            .module_with_calls(C::MODULE)
-            .and_then(|module| module.call(C::FUNCTION, call))?;
+        let call = self.encode(call)?;
         let extra: E = E::new(spec_version, tx_version, account_nonce, genesis_hash);
         let raw_payload = SignedPayload::new(call, extra.extra())?;
         Ok(raw_payload)
@@ -402,7 +407,7 @@ where
 
 /// Wraps an already encoded byte vector, prevents being encoded as a raw byte vector as part of
 /// the transaction payload
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct Encoded(pub Vec<u8>);
 
 impl codec::Encode for Encoded {
diff --git a/src/runtimes.rs b/src/runtimes.rs
index 3ced7ce0b5..2ca64ebe41 100644
--- a/src/runtimes.rs
+++ b/src/runtimes.rs
@@ -31,6 +31,7 @@ use crate::frame::{
         Balances,
     },
     contracts::Contracts,
+    sudo::Sudo,
     system::System,
 };
 
@@ -61,6 +62,8 @@ impl Balances for DefaultNodeRuntime {
 
 impl Contracts for DefaultNodeRuntime {}
 
+impl Sudo for DefaultNodeRuntime {}
+
 /// Concrete type definitions compatible with those for kusama, v0.7
 ///
 /// # Note