1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
// This file is part of Frontier.
//
// Copyright (c) 2019-2022 Moonsong Labs.
// Copyright (c) 2023 Parity Technologies (UK) Ltd.
//
// This program 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.
//
// This program 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 this program. If not, see <https://www.gnu.org/licenses/>.

use crate::{
	solidity::codec::Writer,
	testing::{decode_revert_message, MockHandle},
};
use fp_evm::{Context, PrecompileFailure, PrecompileSet};
use sp_core::{H160, U256};

pub struct PrecompilesModifierTester<P> {
	precompiles: P,
	handle: MockHandle,
}

impl<P: PrecompileSet> PrecompilesModifierTester<P> {
	pub fn new(precompiles: P, from: impl Into<H160>, to: impl Into<H160>) -> Self {
		let to = to.into();
		let mut handle = MockHandle::new(
			to,
			Context {
				address: to,
				caller: from.into(),
				apparent_value: U256::zero(),
			},
		);

		handle.gas_limit = u64::MAX;

		Self {
			precompiles,
			handle,
		}
	}

	fn is_view(&mut self, selector: u32) -> bool {
		// View: calling with static should not revert with static-related message.
		let handle = &mut self.handle;
		handle.is_static = true;
		handle.context.apparent_value = U256::zero();
		handle.input = Writer::new_with_selector(selector).build();

		let res = self.precompiles.execute(handle);

		match res {
			Some(Err(PrecompileFailure::Revert { output, .. })) => {
				let decoded = decode_revert_message(&output);

				dbg!(decoded) != b"Can't call non-static function in static context"
			}
			Some(_) => true,
			None => panic!("tried to check view modifier on unknown precompile"),
		}
	}

	fn is_payable(&mut self, selector: u32) -> bool {
		// Payable: calling with value should not revert with payable-related message.
		let handle = &mut self.handle;
		handle.is_static = false;
		handle.context.apparent_value = U256::one();
		handle.input = Writer::new_with_selector(selector).build();

		let res = self.precompiles.execute(handle);

		match res {
			Some(Err(PrecompileFailure::Revert { output, .. })) => {
				let decoded = decode_revert_message(&output);

				decoded != b"Function is not payable"
			}
			Some(_) => true,
			None => panic!("tried to check payable modifier on unknown precompile"),
		}
	}

	pub fn test_view_modifier(&mut self, selectors: &[u32]) {
		for &s in selectors {
			assert!(
				self.is_view(s),
				"Function doesn't behave like a view function."
			);
			assert!(
				!self.is_payable(s),
				"Function doesn't behave like a non-payable function."
			)
		}
	}

	pub fn test_payable_modifier(&mut self, selectors: &[u32]) {
		for &s in selectors {
			assert!(
				!self.is_view(s),
				"Function doesn't behave like a non-view function."
			);
			assert!(
				self.is_payable(s),
				"Function doesn't behave like a payable function."
			);
		}
	}

	pub fn test_default_modifier(&mut self, selectors: &[u32]) {
		for &s in selectors {
			assert!(
				!self.is_view(s),
				"Function doesn't behave like a non-view function."
			);
			assert!(
				!self.is_payable(s),
				"Function doesn't behave like a non-payable function."
			);
		}
	}
}