polkadot_test_client/
block_builder.rs

1// Copyright (C) Parity Technologies (UK) Ltd.
2// This file is part of Polkadot.
3
4// Polkadot is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8
9// Polkadot is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12// GNU General Public License for more details.
13
14// You should have received a copy of the GNU General Public License
15// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
16
17use crate::Client;
18use codec::{Decode, Encode};
19use polkadot_primitives::{Block, InherentData as ParachainsInherentData};
20use polkadot_test_runtime::UncheckedExtrinsic;
21use polkadot_test_service::GetLastTimestamp;
22use sc_block_builder::{BlockBuilder, BlockBuilderBuilder};
23use sp_api::ProvideRuntimeApi;
24use sp_consensus_babe::{
25	digests::{PreDigest, SecondaryPlainPreDigest},
26	BABE_ENGINE_ID,
27};
28use sp_runtime::{traits::Block as BlockT, Digest, DigestItem};
29use sp_state_machine::BasicExternalities;
30
31/// An extension for the test client to initialize a Polkadot specific block builder.
32pub trait InitPolkadotBlockBuilder {
33	/// Init a Polkadot specific block builder that works for the test runtime.
34	///
35	/// This will automatically create and push the inherents for you to make the block valid for
36	/// the test runtime.
37	fn init_polkadot_block_builder(&self) -> sc_block_builder::BlockBuilder<Block, Client>;
38
39	/// Init a Polkadot specific block builder at a specific block that works for the test runtime.
40	///
41	/// Same as [`InitPolkadotBlockBuilder::init_polkadot_block_builder`] besides that it takes a
42	/// `Hash` to say which should be the parent block of the block that is being build.
43	fn init_polkadot_block_builder_at(
44		&self,
45		hash: <Block as BlockT>::Hash,
46	) -> sc_block_builder::BlockBuilder<Block, Client>;
47}
48
49impl InitPolkadotBlockBuilder for Client {
50	fn init_polkadot_block_builder(&self) -> BlockBuilder<Block, Client> {
51		let chain_info = self.chain_info();
52		self.init_polkadot_block_builder_at(chain_info.best_hash)
53	}
54
55	fn init_polkadot_block_builder_at(
56		&self,
57		hash: <Block as BlockT>::Hash,
58	) -> BlockBuilder<Block, Client> {
59		let last_timestamp =
60			self.runtime_api().get_last_timestamp(hash).expect("Get last timestamp");
61
62		// `MinimumPeriod` is a storage parameter type that requires externalities to access the
63		// value.
64		let minimum_period = BasicExternalities::new_empty()
65			.execute_with(|| polkadot_test_runtime::MinimumPeriod::get());
66
67		let timestamp = if last_timestamp == 0 {
68			std::time::SystemTime::now()
69				.duration_since(std::time::SystemTime::UNIX_EPOCH)
70				.expect("Time is always after UNIX_EPOCH; qed")
71				.as_millis() as u64
72		} else {
73			last_timestamp + minimum_period
74		};
75
76		// `SlotDuration` is a storage parameter type that requires externalities to access the
77		// value.
78		let slot_duration = BasicExternalities::new_empty()
79			.execute_with(|| polkadot_test_runtime::SlotDuration::get());
80
81		let slot = (timestamp / slot_duration).into();
82
83		let digest = Digest {
84			logs: vec![DigestItem::PreRuntime(
85				BABE_ENGINE_ID,
86				PreDigest::SecondaryPlain(SecondaryPlainPreDigest { slot, authority_index: 42 })
87					.encode(),
88			)],
89		};
90
91		let mut block_builder = BlockBuilderBuilder::new(self)
92			.on_parent_block(hash)
93			.fetch_parent_block_number(&self)
94			.expect("Fetches parent block number")
95			.with_inherent_digests(digest)
96			.build()
97			.expect("Creates new block builder for test runtime");
98
99		let mut inherent_data = sp_inherents::InherentData::new();
100
101		inherent_data
102			.put_data(sp_timestamp::INHERENT_IDENTIFIER, &timestamp)
103			.expect("Put timestamp inherent data");
104
105		let parent_header = self
106			.header(hash)
107			.expect("Get the parent block header")
108			.expect("The target block header must exist");
109
110		let parachains_inherent_data = ParachainsInherentData {
111			bitfields: Vec::new(),
112			backed_candidates: Vec::new(),
113			disputes: Vec::new(),
114			parent_header,
115		};
116
117		inherent_data
118			.put_data(
119				polkadot_primitives::PARACHAINS_INHERENT_IDENTIFIER,
120				&parachains_inherent_data,
121			)
122			.expect("Put parachains inherent data");
123
124		let inherents = block_builder.create_inherents(inherent_data).expect("Creates inherents");
125
126		inherents
127			.into_iter()
128			.for_each(|ext| block_builder.push(ext).expect("Pushes inherent"));
129
130		block_builder
131	}
132}
133
134/// Polkadot specific extensions for the [`BlockBuilder`].
135pub trait BlockBuilderExt {
136	/// Push a Polkadot test runtime specific extrinsic to the block.
137	///
138	/// This will internally use the [`BlockBuilder::push`] method, but this method expects a opaque
139	/// extrinsic. So, we provide this wrapper which converts a test runtime specific extrinsic to a
140	/// opaque extrinsic and pushes it to the block.
141	///
142	/// Returns the result of the application of the extrinsic.
143	fn push_polkadot_extrinsic(
144		&mut self,
145		ext: UncheckedExtrinsic,
146	) -> Result<(), sp_blockchain::Error>;
147}
148
149impl BlockBuilderExt for BlockBuilder<'_, Block, Client> {
150	fn push_polkadot_extrinsic(
151		&mut self,
152		ext: UncheckedExtrinsic,
153	) -> Result<(), sp_blockchain::Error> {
154		let encoded = ext.encode();
155		self.push(
156			Decode::decode(&mut &encoded[..]).expect(
157				"The runtime specific extrinsic always decodes to an opaque extrinsic; qed",
158			),
159		)
160	}
161}
polkadot_test_client/block_builder.rs

polkadot_test_client/
block_builder.rs
