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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
/// Utilities for launching a ganache-cli testnet instance
#[cfg(not(target_arch = "wasm32"))]
mod ganache;
#[cfg(not(target_arch = "wasm32"))]
pub use ganache::{Ganache, GanacheInstance};

/// Utilities for launching a go-ethereum dev-mode instance
#[cfg(not(target_arch = "wasm32"))]
mod geth;
#[cfg(not(target_arch = "wasm32"))]
pub use geth::{Geth, GethInstance};

/// Utilities for launching an anvil instance
#[cfg(not(target_arch = "wasm32"))]
mod anvil;
#[cfg(not(target_arch = "wasm32"))]
pub use anvil::{Anvil, AnvilInstance};

/// Moonbeam utils
pub mod moonbeam;

mod hash;
pub use hash::{hash_message, id, keccak256, serialize};

mod units;
pub use units::Units;

/// Re-export RLP
pub use rlp;

/// Re-export hex
pub use hex;

use crate::types::{Address, Bytes, I256, U256};
use elliptic_curve::sec1::ToEncodedPoint;
use ethabi::ethereum_types::FromDecStrErr;
use k256::{ecdsa::SigningKey, PublicKey as K256PublicKey};
use std::convert::{TryFrom, TryInto};
use thiserror::Error;

#[derive(Error, Debug)]
pub enum ConversionError {
    #[error("Unknown units: {0}")]
    UnrecognizedUnits(String),
    #[error("bytes32 strings must not exceed 32 bytes in length")]
    TextTooLong,
    #[error(transparent)]
    Utf8Error(#[from] std::str::Utf8Error),
    #[error(transparent)]
    InvalidFloat(#[from] std::num::ParseFloatError),
    #[error(transparent)]
    FromDecStrError(#[from] FromDecStrErr),
}

/// 1 Ether = 1e18 Wei == 0x0de0b6b3a7640000 Wei
pub const WEI_IN_ETHER: U256 = U256([0x0de0b6b3a7640000, 0x0, 0x0, 0x0]);

/// The number of blocks from the past for which the fee rewards are fetched for fee estimation.
pub const EIP1559_FEE_ESTIMATION_PAST_BLOCKS: u64 = 10;
/// The default percentile of gas premiums that are fetched for fee estimation.
pub const EIP1559_FEE_ESTIMATION_REWARD_PERCENTILE: f64 = 5.0;
/// The default max priority fee per gas, used in case the base fee is within a threshold.
pub const EIP1559_FEE_ESTIMATION_DEFAULT_PRIORITY_FEE: u64 = 3_000_000_000;
/// The threshold for base fee below which we use the default priority fee, and beyond which we
/// estimate an appropriate value for priority fee.
pub const EIP1559_FEE_ESTIMATION_PRIORITY_FEE_TRIGGER: u64 = 100_000_000_000;
/// The threshold max change/difference (in %) at which we will ignore the fee history values
/// under it.
pub const EIP1559_FEE_ESTIMATION_THRESHOLD_MAX_CHANGE: i64 = 200;

/// Format the output for the user which prefer to see values
/// in ether (instead of wei)
///
/// Divides the input by 1e18
pub fn format_ether<T: Into<U256>>(amount: T) -> U256 {
    amount.into() / WEI_IN_ETHER
}

/// Divides the provided amount with 10^{units} provided.
///
/// ```
/// use ethers_core::{types::U256, utils::format_units};
///
/// let eth = format_units(1395633240123456000_u128, "ether").unwrap();
/// assert_eq!(eth.parse::<f64>().unwrap(), 1.395633240123456);
///
/// let eth = format_units(U256::from_dec_str("1395633240123456000").unwrap(), "ether").unwrap();
/// assert_eq!(eth.parse::<f64>().unwrap(), 1.395633240123456);
///
/// let eth = format_units(U256::from_dec_str("1395633240123456789").unwrap(), "ether").unwrap();
/// assert_eq!(eth, "1.395633240123456789");
/// ```
pub fn format_units<T, K>(amount: T, units: K) -> Result<String, ConversionError>
where
    T: Into<U256>,
    K: TryInto<Units, Error = ConversionError>,
{
    let units = units.try_into()?;
    let amount = amount.into();
    let amount_decimals = amount % U256::from(10_u128.pow(units.as_num()));
    let amount_integer = amount / U256::from(10_u128.pow(units.as_num()));
    Ok(format!(
        "{}.{:0width$}",
        amount_integer,
        amount_decimals.as_u128(),
        width = units.as_num() as usize
    ))
}

/// Converts the input to a U256 and converts from Ether to Wei.
///
/// ```
/// use ethers_core::{types::U256, utils::{parse_ether, WEI_IN_ETHER}};
///
/// let eth = U256::from(WEI_IN_ETHER);
/// assert_eq!(eth, parse_ether(1u8).unwrap());
/// assert_eq!(eth, parse_ether(1usize).unwrap());
/// assert_eq!(eth, parse_ether("1").unwrap());
/// ```
pub fn parse_ether<S>(eth: S) -> Result<U256, ConversionError>
where
    S: ToString,
{
    parse_units(eth, "ether")
}

/// Multiplies the provided amount with 10^{units} provided.
///
/// ```
/// use ethers_core::{types::U256, utils::parse_units};
/// let amount_in_eth = U256::from_dec_str("15230001000000000000").unwrap();
/// let amount_in_gwei = U256::from_dec_str("15230001000").unwrap();
/// let amount_in_wei = U256::from_dec_str("15230001000").unwrap();
/// assert_eq!(amount_in_eth, parse_units("15.230001000000000000", "ether").unwrap());
/// assert_eq!(amount_in_gwei, parse_units("15.230001000000000000", "gwei").unwrap());
/// assert_eq!(amount_in_wei, parse_units("15230001000", "wei").unwrap());
/// ```
/// Example of trying to parse decimal WEI, which should fail, as WEI is the smallest
/// ETH denominator. 1 ETH = 10^18 WEI.
/// ```should_panic
/// use ethers_core::{types::U256, utils::parse_units};
/// let amount_in_wei = U256::from_dec_str("15230001000").unwrap();
/// assert_eq!(amount_in_wei, parse_units("15.230001000000000000", "wei").unwrap());
/// ```
pub fn parse_units<K, S>(amount: S, units: K) -> Result<U256, ConversionError>
where
    S: ToString,
    K: TryInto<Units, Error = ConversionError> + Copy,
{
    let float_n: f64 =
        amount.to_string().parse::<f64>()? * 10u64.pow(units.try_into()?.as_num()) as f64;
    let u256_n: U256 = U256::from_dec_str(&float_n.round().to_string())?;
    Ok(u256_n)
}
/// The address for an Ethereum contract is deterministically computed from the
/// address of its creator (sender) and how many transactions the creator has
/// sent (nonce). The sender and nonce are RLP encoded and then hashed with Keccak-256.
pub fn get_contract_address(sender: impl Into<Address>, nonce: impl Into<U256>) -> Address {
    let mut stream = rlp::RlpStream::new();
    stream.begin_list(2);
    stream.append(&sender.into());
    stream.append(&nonce.into());

    let hash = keccak256(&stream.out());

    let mut bytes = [0u8; 20];
    bytes.copy_from_slice(&hash[12..]);
    Address::from(bytes)
}

/// Returns the CREATE2 address of a smart contract as specified in
/// [EIP1014](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1014.md)
///
/// keccak256( 0xff ++ senderAddress ++ salt ++ keccak256(init_code))[12..]
pub fn get_create2_address(
    from: impl Into<Address>,
    salt: impl Into<Bytes>,
    init_code: impl Into<Bytes>,
) -> Address {
    get_create2_address_from_hash(from, salt, keccak256(init_code.into().as_ref()).to_vec())
}

/// Returns the CREATE2 address of a smart contract as specified in
/// [EIP1014](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1014.md),
/// taking the pre-computed hash of the init code as input.
///
/// keccak256( 0xff ++ senderAddress ++ salt ++ keccak256(init_code))[12..]
///
/// # Example
///
/// Calculate the address of a UniswapV3 pool.
///
/// ```
/// use ethers_core::{
///     abi,
///     abi::Token,
///     types::{Address, Bytes, U256},
///     utils::{get_create2_address_from_hash, keccak256},
/// };
///
/// let UNISWAP_V3_POOL_INIT_CODE_HASH = Bytes::from(
///     hex::decode("e34f199b19b2b4f47f68442619d555527d244f78a3297ea89325f843f87b8b54").unwrap(),
/// );
/// let factory: Address = "0x1F98431c8aD98523631AE4a59f267346ea31F984"
///     .parse()
///     .unwrap();
/// let token0: Address = "0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48"
///     .parse()
///     .unwrap();
/// let token1: Address = "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2"
///     .parse()
///     .unwrap();
/// let fee = 500;
///
/// // abi.encode(token0 as address, token1 as address, fee as uint256)
/// let input = abi::encode(&vec![
///     Token::Address(token0),
///     Token::Address(token1),
///     Token::Uint(U256::from(fee)),
/// ]);
///
/// // keccak256(abi.encode(token0, token1, fee))
/// let salt = keccak256(&input);
/// let pool_address =
///     get_create2_address_from_hash(factory, salt.to_vec(), UNISWAP_V3_POOL_INIT_CODE_HASH);
///
/// assert_eq!(
///     pool_address,
///     "0x88e6A0c2dDD26FEEb64F039a2c41296FcB3f5640" // USDC/ETH pool address
///         .parse()
///         .unwrap()
/// );
/// ```
pub fn get_create2_address_from_hash(
    from: impl Into<Address>,
    salt: impl Into<Bytes>,
    init_code_hash: impl Into<Bytes>,
) -> Address {
    let bytes =
        [&[0xff], from.into().as_bytes(), salt.into().as_ref(), init_code_hash.into().as_ref()]
            .concat();

    let hash = keccak256(&bytes);

    let mut bytes = [0u8; 20];
    bytes.copy_from_slice(&hash[12..]);
    Address::from(bytes)
}

/// Converts a K256 SigningKey to an Ethereum Address
pub fn secret_key_to_address(secret_key: &SigningKey) -> Address {
    let public_key = K256PublicKey::from(&secret_key.verifying_key());
    let public_key = public_key.to_encoded_point(/* compress = */ false);
    let public_key = public_key.as_bytes();
    debug_assert_eq!(public_key[0], 0x04);
    let hash = keccak256(&public_key[1..]);
    Address::from_slice(&hash[12..])
}

/// Converts an Ethereum address to the checksum encoding
/// Ref: <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-55.md>
pub fn to_checksum(addr: &Address, chain_id: Option<u8>) -> String {
    let prefixed_addr = match chain_id {
        Some(chain_id) => format!("{}0x{:x}", chain_id, addr),
        None => format!("{:x}", addr),
    };
    let hash = hex::encode(keccak256(&prefixed_addr));
    let hash = hash.as_bytes();

    let addr_hex = hex::encode(addr.as_bytes());
    let addr_hex = addr_hex.as_bytes();

    addr_hex.iter().zip(hash).fold("0x".to_owned(), |mut encoded, (addr, hash)| {
        encoded.push(if *hash >= 56 {
            addr.to_ascii_uppercase() as char
        } else {
            addr.to_ascii_lowercase() as char
        });
        encoded
    })
}

/// Returns a bytes32 string representation of text. If the length of text exceeds 32 bytes,
/// an error is returned.
pub fn format_bytes32_string(text: &str) -> Result<[u8; 32], ConversionError> {
    let str_bytes: &[u8] = text.as_bytes();
    if str_bytes.len() > 32 {
        return Err(ConversionError::TextTooLong)
    }

    let mut bytes32: [u8; 32] = [0u8; 32];
    bytes32[..str_bytes.len()].copy_from_slice(str_bytes);

    Ok(bytes32)
}

/// Returns the decoded string represented by the bytes32 encoded data.
pub fn parse_bytes32_string(bytes: &[u8; 32]) -> Result<&str, ConversionError> {
    let mut length = 0;
    while length < 32 && bytes[length] != 0 {
        length += 1;
    }

    Ok(std::str::from_utf8(&bytes[..length])?)
}

/// The default EIP-1559 fee estimator which is based on the work by [MyCrypto](https://github.com/MyCryptoHQ/MyCrypto/blob/master/src/services/ApiService/Gas/eip1559.ts)
pub fn eip1559_default_estimator(base_fee_per_gas: U256, rewards: Vec<Vec<U256>>) -> (U256, U256) {
    let max_priority_fee_per_gas =
        if base_fee_per_gas < U256::from(EIP1559_FEE_ESTIMATION_PRIORITY_FEE_TRIGGER) {
            U256::from(EIP1559_FEE_ESTIMATION_DEFAULT_PRIORITY_FEE)
        } else {
            std::cmp::max(
                estimate_priority_fee(rewards),
                U256::from(EIP1559_FEE_ESTIMATION_DEFAULT_PRIORITY_FEE),
            )
        };
    let potential_max_fee = base_fee_surged(base_fee_per_gas);
    let max_fee_per_gas = if max_priority_fee_per_gas > potential_max_fee {
        max_priority_fee_per_gas + potential_max_fee
    } else {
        potential_max_fee
    };
    (max_fee_per_gas, max_priority_fee_per_gas)
}

fn estimate_priority_fee(rewards: Vec<Vec<U256>>) -> U256 {
    let mut rewards: Vec<U256> =
        rewards.iter().map(|r| r[0]).filter(|r| *r > U256::zero()).collect();
    if rewards.is_empty() {
        return U256::zero()
    }
    if rewards.len() == 1 {
        return rewards[0]
    }
    // Sort the rewards as we will eventually take the median.
    rewards.sort();

    // A copy of the same vector is created for convenience to calculate percentage change
    // between subsequent fee values.
    let mut rewards_copy = rewards.clone();
    rewards_copy.rotate_left(1);

    let mut percentage_change: Vec<I256> = rewards
        .iter()
        .zip(rewards_copy.iter())
        .map(|(a, b)| {
            let a = I256::try_from(*a).expect("priority fee overflow");
            let b = I256::try_from(*b).expect("priority fee overflow");
            ((b - a) * 100.into()) / a
        })
        .collect();
    percentage_change.pop();

    // Fetch the max of the percentage change, and that element's index.
    let max_change = percentage_change.iter().max().unwrap();
    let max_change_index = percentage_change.iter().position(|&c| c == *max_change).unwrap();

    // If we encountered a big change in fees at a certain position, then consider only
    // the values >= it.
    let values = if *max_change >= EIP1559_FEE_ESTIMATION_THRESHOLD_MAX_CHANGE.into() &&
        (max_change_index >= (rewards.len() / 2))
    {
        rewards[max_change_index..].to_vec()
    } else {
        rewards
    };

    // Return the median.
    values[values.len() / 2]
}

fn base_fee_surged(base_fee_per_gas: U256) -> U256 {
    if base_fee_per_gas <= U256::from(40_000_000_000u64) {
        base_fee_per_gas * 2
    } else if base_fee_per_gas <= U256::from(100_000_000_000u64) {
        base_fee_per_gas * 16 / 10
    } else if base_fee_per_gas <= U256::from(200_000_000_000u64) {
        base_fee_per_gas * 14 / 10
    } else {
        base_fee_per_gas * 12 / 10
    }
}

/// A bit of hack to find an unused TCP port.
///
/// Does not guarantee that the given port is unused after the function exists, just that it was
/// unused before the function started (i.e., it does not reserve a port).
#[cfg(not(target_arch = "wasm32"))]
pub(crate) fn unused_port() -> u16 {
    let listener = std::net::TcpListener::bind("127.0.0.1:0")
        .expect("Failed to create TCP listener to find unused port");

    let local_addr =
        listener.local_addr().expect("Failed to read TCP listener local_addr to find unused port");
    local_addr.port()
}

#[cfg(test)]
mod tests {
    use super::*;
    use hex_literal::hex;

    #[test]
    fn wei_in_ether() {
        assert_eq!(WEI_IN_ETHER.as_u64(), 1e18 as u64);
    }

    #[test]
    fn test_format_units() {
        let gwei_in_ether = format_units(WEI_IN_ETHER, 9).unwrap();
        assert_eq!(gwei_in_ether.parse::<f64>().unwrap() as u64, 1e9 as u64);

        let eth = format_units(WEI_IN_ETHER, "ether").unwrap();
        assert_eq!(eth.parse::<f64>().unwrap() as u64, 1);

        let eth = format_units(1395633240123456000_u128, "ether").unwrap();
        assert_eq!(eth.parse::<f64>().unwrap(), 1.395633240123456);

        let eth =
            format_units(U256::from_dec_str("1395633240123456000").unwrap(), "ether").unwrap();
        assert_eq!(eth.parse::<f64>().unwrap(), 1.395633240123456);

        let eth =
            format_units(U256::from_dec_str("1395633240123456789").unwrap(), "ether").unwrap();
        assert_eq!(eth, "1.395633240123456789");

        let eth =
            format_units(U256::from_dec_str("1005633240123456789").unwrap(), "ether").unwrap();
        assert_eq!(eth, "1.005633240123456789");
    }

    #[test]
    fn test_parse_units() {
        let gwei = parse_units(1.5, 9).unwrap();
        assert_eq!(gwei.as_u64(), 15e8 as u64);

        let token = parse_units(1163.56926418, 8).unwrap();
        assert_eq!(token.as_u64(), 116356926418);

        let eth_dec_float = parse_units(1.39563324, "ether").unwrap();
        assert_eq!(eth_dec_float, U256::from_dec_str("1395633240000000000").unwrap());

        let eth_dec_string = parse_units("1.39563324", "ether").unwrap();
        assert_eq!(eth_dec_string, U256::from_dec_str("1395633240000000000").unwrap());

        let eth = parse_units(1, "ether").unwrap();
        assert_eq!(eth, WEI_IN_ETHER);
    }

    #[test]
    fn addr_checksum() {
        let addr_list = vec![
            // mainnet
            (
                None,
                "27b1fdb04752bbc536007a920d24acb045561c26",
                "0x27b1fdb04752bbc536007a920d24acb045561c26",
            ),
            (
                None,
                "3599689e6292b81b2d85451025146515070129bb",
                "0x3599689E6292b81B2d85451025146515070129Bb",
            ),
            (
                None,
                "42712d45473476b98452f434e72461577d686318",
                "0x42712D45473476b98452f434e72461577D686318",
            ),
            (
                None,
                "52908400098527886e0f7030069857d2e4169ee7",
                "0x52908400098527886E0F7030069857D2E4169EE7",
            ),
            (
                None,
                "5aaeb6053f3e94c9b9a09f33669435e7ef1beaed",
                "0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed",
            ),
            (
                None,
                "6549f4939460de12611948b3f82b88c3c8975323",
                "0x6549f4939460DE12611948b3f82b88C3C8975323",
            ),
            (
                None,
                "66f9664f97f2b50f62d13ea064982f936de76657",
                "0x66f9664f97F2b50F62D13eA064982f936dE76657",
            ),
            (
                None,
                "88021160c5c792225e4e5452585947470010289d",
                "0x88021160C5C792225E4E5452585947470010289D",
            ),
            // rsk mainnet
            (
                Some(30),
                "27b1fdb04752bbc536007a920d24acb045561c26",
                "0x27b1FdB04752BBc536007A920D24ACB045561c26",
            ),
            (
                Some(30),
                "3599689e6292b81b2d85451025146515070129bb",
                "0x3599689E6292B81B2D85451025146515070129Bb",
            ),
            (
                Some(30),
                "42712d45473476b98452f434e72461577d686318",
                "0x42712D45473476B98452f434E72461577d686318",
            ),
            (
                Some(30),
                "52908400098527886e0f7030069857d2e4169ee7",
                "0x52908400098527886E0F7030069857D2E4169ee7",
            ),
            (
                Some(30),
                "5aaeb6053f3e94c9b9a09f33669435e7ef1beaed",
                "0x5aaEB6053f3e94c9b9a09f33669435E7ef1bEAeD",
            ),
            (
                Some(30),
                "6549f4939460de12611948b3f82b88c3c8975323",
                "0x6549F4939460DE12611948B3F82B88C3C8975323",
            ),
            (
                Some(30),
                "66f9664f97f2b50f62d13ea064982f936de76657",
                "0x66F9664f97f2B50F62d13EA064982F936de76657",
            ),
        ];

        for (chain_id, addr, checksummed_addr) in addr_list {
            let addr = addr.parse::<Address>().unwrap();
            assert_eq!(to_checksum(&addr, chain_id), String::from(checksummed_addr));
        }
    }

    #[test]
    fn contract_address() {
        // http://ethereum.stackexchange.com/questions/760/how-is-the-address-of-an-ethereum-contract-computed
        let from = "6ac7ea33f8831ea9dcc53393aaa88b25a785dbf0".parse::<Address>().unwrap();
        for (nonce, expected) in [
            "cd234a471b72ba2f1ccf0a70fcaba648a5eecd8d",
            "343c43a37d37dff08ae8c4a11544c718abb4fcf8",
            "f778b86fa74e846c4f0a1fbd1335fe81c00a0c91",
            "fffd933a0bc612844eaf0c6fe3e5b8e9b6c1d19c",
        ]
        .iter()
        .enumerate()
        {
            let address = get_contract_address(from, nonce);
            assert_eq!(address, expected.parse::<Address>().unwrap());
        }
    }

    #[test]
    // Test vectors from https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1014.md#examples
    fn create2_address() {
        for (from, salt, init_code, expected) in &[
            (
                "0000000000000000000000000000000000000000",
                "0000000000000000000000000000000000000000000000000000000000000000",
                "00",
                "4D1A2e2bB4F88F0250f26Ffff098B0b30B26BF38",
            ),
            (
                "deadbeef00000000000000000000000000000000",
                "0000000000000000000000000000000000000000000000000000000000000000",
                "00",
                "B928f69Bb1D91Cd65274e3c79d8986362984fDA3",
            ),
            (
                "deadbeef00000000000000000000000000000000",
                "000000000000000000000000feed000000000000000000000000000000000000",
                "00",
                "D04116cDd17beBE565EB2422F2497E06cC1C9833",
            ),
            (
                "0000000000000000000000000000000000000000",
                "0000000000000000000000000000000000000000000000000000000000000000",
                "deadbeef",
                "70f2b2914A2a4b783FaEFb75f459A580616Fcb5e",
            ),
            (
                "00000000000000000000000000000000deadbeef",
                "00000000000000000000000000000000000000000000000000000000cafebabe",
                "deadbeef",
                "60f3f640a8508fC6a86d45DF051962668E1e8AC7",
            ),
            (
                "00000000000000000000000000000000deadbeef",
                "00000000000000000000000000000000000000000000000000000000cafebabe",
                "deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef",
                "1d8bfDC5D46DC4f61D6b6115972536eBE6A8854C",
            ),
            (
                "0000000000000000000000000000000000000000",
                "0000000000000000000000000000000000000000000000000000000000000000",
                "",
                "E33C0C7F7df4809055C3ebA6c09CFe4BaF1BD9e0",
            ),
        ] {
            // get_create2_address()
            let from = from.parse::<Address>().unwrap();
            let salt = hex::decode(salt).unwrap();
            let init_code = hex::decode(init_code).unwrap();
            let expected = expected.parse::<Address>().unwrap();
            assert_eq!(expected, get_create2_address(from, salt.clone(), init_code.clone()));

            // get_create2_address_from_hash()
            let init_code_hash = keccak256(init_code).to_vec();
            assert_eq!(expected, get_create2_address_from_hash(from, salt, init_code_hash))
        }
    }

    #[test]
    fn bytes32_string_parsing() {
        let text_bytes_list = vec![
            ("", hex!("0000000000000000000000000000000000000000000000000000000000000000")),
            ("A", hex!("4100000000000000000000000000000000000000000000000000000000000000")),
            (
                "ABCDEFGHIJKLMNOPQRSTUVWXYZ012345",
                hex!("4142434445464748494a4b4c4d4e4f505152535455565758595a303132333435"),
            ),
            (
                "!@#$%^&*(),./;'[]",
                hex!("21402324255e262a28292c2e2f3b275b5d000000000000000000000000000000"),
            ),
        ];

        for (text, bytes) in text_bytes_list {
            assert_eq!(text, parse_bytes32_string(&bytes).unwrap());
        }
    }

    #[test]
    fn bytes32_string_formatting() {
        let text_bytes_list = vec![
            ("", hex!("0000000000000000000000000000000000000000000000000000000000000000")),
            ("A", hex!("4100000000000000000000000000000000000000000000000000000000000000")),
            (
                "ABCDEFGHIJKLMNOPQRSTUVWXYZ012345",
                hex!("4142434445464748494a4b4c4d4e4f505152535455565758595a303132333435"),
            ),
            (
                "!@#$%^&*(),./;'[]",
                hex!("21402324255e262a28292c2e2f3b275b5d000000000000000000000000000000"),
            ),
        ];

        for (text, bytes) in text_bytes_list {
            assert_eq!(bytes, format_bytes32_string(text).unwrap());
        }
    }

    #[test]
    fn bytes32_string_formatting_too_long() {
        assert!(matches!(
            format_bytes32_string("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456").unwrap_err(),
            ConversionError::TextTooLong
        ));
    }

    #[test]
    fn test_eip1559_default_estimator() {
        // If the base fee is below the triggering base fee, we should get the default priority fee
        // with the base fee surged.
        let base_fee_per_gas = U256::from(EIP1559_FEE_ESTIMATION_PRIORITY_FEE_TRIGGER) - 1;
        let rewards: Vec<Vec<U256>> = vec![vec![]];
        let (base_fee, priority_fee) = eip1559_default_estimator(base_fee_per_gas, rewards);
        assert_eq!(priority_fee, U256::from(EIP1559_FEE_ESTIMATION_DEFAULT_PRIORITY_FEE));
        assert_eq!(base_fee, base_fee_surged(base_fee_per_gas));

        // If the base fee is above the triggering base fee, we calculate the priority fee using
        // the fee history (rewards).
        let base_fee_per_gas = U256::from(EIP1559_FEE_ESTIMATION_PRIORITY_FEE_TRIGGER) + 1;
        let rewards: Vec<Vec<U256>> = vec![
            vec![100_000_000_000u64.into()],
            vec![105_000_000_000u64.into()],
            vec![102_000_000_000u64.into()],
        ]; // say, last 3 blocks
        let (base_fee, priority_fee) = eip1559_default_estimator(base_fee_per_gas, rewards.clone());
        assert_eq!(base_fee, base_fee_surged(base_fee_per_gas));
        assert_eq!(priority_fee, estimate_priority_fee(rewards.clone()));

        // The median should be taken because none of the changes are big enough to ignore values.
        assert_eq!(estimate_priority_fee(rewards), 102_000_000_000u64.into());

        // Ensure fee estimation doesn't panic when overflowing a u32. This had been a divide by
        // zero.
        let overflow = U256::from(u32::MAX) + 1;
        let rewards_overflow: Vec<Vec<U256>> = vec![vec![overflow], vec![overflow]];
        assert_eq!(estimate_priority_fee(rewards_overflow), overflow);
    }
}