Offchain Workers: Example Pallet (#4989)

* Example of offchain worker pallet. * Fix compilation issues. * Use serde_json to parse JSON. * Add some basic tests. * Working on docs. * Fix compilation * Finish docs for signed. * Work on unsigned send. * Add some tests and missing docs. * Add example of StorageValueRef * Add weight. * Extra \n * Fix im-online test. * Bump runtime. * Fix tests. * Apply suggestions from code review Co-Authored-By: Joshy Orndorff <JoshOrndorff@users.noreply.github.com> Co-Authored-By: Gavin Wood <gavin@parity.io> * Address review comments. Co-authored-by: Joshy Orndorff <JoshOrndorff@users.noreply.github.com> Co-authored-by: Gavin Wood <github@gavwood.com>
2026-04-28 07:27:55 +00:00 · 2020-02-20 15:21:34 +01:00
parent 5bf644b768
commit 9a0b8b5be5
11 changed files with 832 additions and 17 deletions
@@ -0,0 +1,210 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate 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.
+
+// Substrate 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.  If not, see <http://www.gnu.org/licenses/>.
+
+use crate::*;
+
+use codec::Decode;
+use frame_support::{
+	assert_ok, impl_outer_origin, parameter_types,
+	weights::{GetDispatchInfo, Weight},
+};
+use sp_core::{
+	H256,
+	offchain::{OffchainExt, TransactionPoolExt, testing},
+	testing::KeyStore,
+	traits::KeystoreExt,
+};
+use sp_runtime::{
+	Perbill, RuntimeAppPublic,
+	testing::{Header, TestXt},
+	traits::{BlakeTwo256, IdentityLookup, Extrinsic as ExtrinsicsT},
+};
+
+impl_outer_origin! {
+	pub enum Origin for Test  where system = frame_system {}
+}
+
+// For testing the module, we construct most of a mock runtime. This means
+// first constructing a configuration type (`Test`) which `impl`s each of the
+// configuration traits of modules we want to use.
+#[derive(Clone, Eq, PartialEq)]
+pub struct Test;
+parameter_types! {
+	pub const BlockHashCount: u64 = 250;
+	pub const MaximumBlockWeight: Weight = 1024;
+	pub const MaximumBlockLength: u32 = 2 * 1024;
+	pub const AvailableBlockRatio: Perbill = Perbill::one();
+}
+impl frame_system::Trait for Test {
+	type Origin = Origin;
+	type Index = u64;
+	type BlockNumber = u64;
+	type Hash = H256;
+	type Call = ();
+	type Hashing = BlakeTwo256;
+	type AccountId = sp_core::sr25519::Public;
+	type Lookup = IdentityLookup<Self::AccountId>;
+	type Header = Header;
+	type Event = ();
+	type BlockHashCount = BlockHashCount;
+	type MaximumBlockWeight = MaximumBlockWeight;
+	type MaximumBlockLength = MaximumBlockLength;
+	type AvailableBlockRatio = AvailableBlockRatio;
+	type Version = ();
+	type ModuleToIndex = ();
+	type OnReapAccount = ();
+	type OnNewAccount = ();
+	type AccountData = ();
+}
+
+type Extrinsic = TestXt<Call<Test>, ()>;
+type SubmitTransaction = frame_system::offchain::TransactionSubmitter<
+	crypto::Public,
+	Test,
+	Extrinsic
+>;
+
+impl frame_system::offchain::CreateTransaction<Test, Extrinsic> for Test {
+	type Public = sp_core::sr25519::Public;
+	type Signature = sp_core::sr25519::Signature;
+
+	fn create_transaction<F: frame_system::offchain::Signer<Self::Public, Self::Signature>>(
+		call: <Extrinsic as ExtrinsicsT>::Call,
+		_public: Self::Public,
+		_account: <Test as frame_system::Trait>::AccountId,
+		nonce: <Test as frame_system::Trait>::Index,
+	) -> Option<(<Extrinsic as ExtrinsicsT>::Call, <Extrinsic as ExtrinsicsT>::SignaturePayload)> {
+		Some((call, (nonce, ())))
+	}
+}
+
+parameter_types! {
+	pub const GracePeriod: u64 = 5;
+	pub const UnsignedInterval: u64 = 128;
+}
+
+impl Trait for Test {
+	type Event = ();
+	type Call = Call<Test>;
+	type SubmitSignedTransaction = SubmitTransaction;
+	type SubmitUnsignedTransaction = SubmitTransaction;
+	type GracePeriod = GracePeriod;
+	type UnsignedInterval = UnsignedInterval;
+}
+
+type Example = Module<Test>;
+
+#[test]
+fn it_aggregates_the_price() {
+	sp_io::TestExternalities::default().execute_with(|| {
+		assert_eq!(Example::average_price(), None);
+
+		assert_ok!(Example::submit_price(Origin::signed(Default::default()), 27));
+		assert_eq!(Example::average_price(), Some(27));
+
+		assert_ok!(Example::submit_price(Origin::signed(Default::default()), 43));
+		assert_eq!(Example::average_price(), Some(35));
+	});
+}
+
+#[test]
+fn should_make_http_call_and_parse_result() {
+	let (offchain, state) = testing::TestOffchainExt::new();
+	let mut t = sp_io::TestExternalities::default();
+	t.register_extension(OffchainExt::new(offchain));
+
+	price_oracle_response(&mut state.write());
+
+	t.execute_with(|| {
+		// when
+		let price = Example::fetch_price().unwrap();
+		// then
+		assert_eq!(price, 15522);
+	});
+}
+
+#[test]
+fn should_submit_signed_transaction_on_chain() {
+	const PHRASE: &str = "news slush supreme milk chapter athlete soap sausage put clutch what kitten";
+
+	let (offchain, offchain_state) = testing::TestOffchainExt::new();
+	let (pool, pool_state) = testing::TestTransactionPoolExt::new();
+	let keystore = KeyStore::new();
+	keystore.write().sr25519_generate_new(
+		crate::crypto::Public::ID,
+		Some(&format!("{}/hunter1", PHRASE))
+	).unwrap();
+
+
+	let mut t = sp_io::TestExternalities::default();
+	t.register_extension(OffchainExt::new(offchain));
+	t.register_extension(TransactionPoolExt::new(pool));
+	t.register_extension(KeystoreExt(keystore));
+
+	price_oracle_response(&mut offchain_state.write());
+
+	t.execute_with(|| {
+		// when
+		Example::fetch_price_and_send_signed().unwrap();
+		// then
+		let tx = pool_state.write().transactions.pop().unwrap();
+		assert!(pool_state.read().transactions.is_empty());
+		let tx = Extrinsic::decode(&mut &*tx).unwrap();
+		assert_eq!(tx.signature.unwrap().0, 0);
+		assert_eq!(tx.call, Call::submit_price(15522));
+	});
+}
+
+#[test]
+fn should_submit_unsigned_transaction_on_chain() {
+	let (offchain, offchain_state) = testing::TestOffchainExt::new();
+	let (pool, pool_state) = testing::TestTransactionPoolExt::new();
+	let mut t = sp_io::TestExternalities::default();
+	t.register_extension(OffchainExt::new(offchain));
+	t.register_extension(TransactionPoolExt::new(pool));
+
+	price_oracle_response(&mut offchain_state.write());
+
+	t.execute_with(|| {
+		// when
+		Example::fetch_price_and_send_unsigned(1).unwrap();
+		// then
+		let tx = pool_state.write().transactions.pop().unwrap();
+		assert!(pool_state.read().transactions.is_empty());
+		let tx = Extrinsic::decode(&mut &*tx).unwrap();
+		assert_eq!(tx.signature, None);
+		assert_eq!(tx.call, Call::submit_price_unsigned(1, 15522));
+	});
+}
+
+#[test]
+fn weights_work() {
+	// must have a default weight.
+	let default_call = <Call<Test>>::submit_price(10);
+	let info = default_call.get_dispatch_info();
+	// aka. `let info = <Call<Test> as GetDispatchInfo>::get_dispatch_info(&default_call);`
+	assert_eq!(info.weight, 10_000);
+}
+
+fn price_oracle_response(state: &mut testing::OffchainState) {
+	state.expect_request(0, testing::PendingRequest {
+		method: "GET".into(),
+		uri: "https://min-api.cryptocompare.com/data/price?fsym=BTC&tsyms=USD".into(),
+		response: Some(br#"{"USD": 155.23}"#.to_vec()),
+		sent: true,
+		..Default::default()
+	});
+}