foundry_evm_traces/decoder/
mod.rs

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
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
use crate::{
    debug::DebugTraceIdentifier,
    identifier::{
        AddressIdentity, LocalTraceIdentifier, SingleSignaturesIdentifier, TraceIdentifier,
    },
    CallTrace, CallTraceArena, CallTraceNode, DecodedCallData,
};
use alloy_dyn_abi::{DecodedEvent, DynSolValue, EventExt, FunctionExt, JsonAbiExt};
use alloy_json_abi::{Error, Event, Function, JsonAbi};
use alloy_primitives::{
    map::{hash_map::Entry, HashMap},
    Address, LogData, Selector, B256,
};
use foundry_common::{
    abi::get_indexed_event, fmt::format_token, get_contract_name, ContractsByArtifact, SELECTOR_LEN,
};
use foundry_evm_core::{
    abi::{Console, HardhatConsole, Vm, HARDHAT_CONSOLE_SELECTOR_PATCHES},
    constants::{
        CALLER, CHEATCODE_ADDRESS, DEFAULT_CREATE2_DEPLOYER, HARDHAT_CONSOLE_ADDRESS,
        TEST_CONTRACT_ADDRESS,
    },
    decode::RevertDecoder,
    precompiles::{
        BLAKE_2F, EC_ADD, EC_MUL, EC_PAIRING, EC_RECOVER, IDENTITY, MOD_EXP, POINT_EVALUATION,
        RIPEMD_160, SHA_256,
    },
};
use itertools::Itertools;
use revm_inspectors::tracing::types::{DecodedCallLog, DecodedCallTrace};
use std::{collections::BTreeMap, sync::OnceLock};

mod precompiles;

/// Build a new [CallTraceDecoder].
#[derive(Default)]
#[must_use = "builders do nothing unless you call `build` on them"]
pub struct CallTraceDecoderBuilder {
    decoder: CallTraceDecoder,
}

impl CallTraceDecoderBuilder {
    /// Create a new builder.
    #[inline]
    pub fn new() -> Self {
        Self { decoder: CallTraceDecoder::new().clone() }
    }

    /// Add known labels to the decoder.
    #[inline]
    pub fn with_labels(mut self, labels: impl IntoIterator<Item = (Address, String)>) -> Self {
        self.decoder.labels.extend(labels);
        self
    }

    /// Add known errors to the decoder.
    #[inline]
    pub fn with_abi(mut self, abi: &JsonAbi) -> Self {
        self.decoder.collect_abi(abi, None);
        self
    }

    /// Add known contracts to the decoder.
    #[inline]
    pub fn with_known_contracts(mut self, contracts: &ContractsByArtifact) -> Self {
        trace!(target: "evm::traces", len=contracts.len(), "collecting known contract ABIs");
        for contract in contracts.values() {
            self.decoder.collect_abi(&contract.abi, None);
        }
        self
    }

    /// Add known contracts to the decoder from a `LocalTraceIdentifier`.
    #[inline]
    pub fn with_local_identifier_abis(self, identifier: &LocalTraceIdentifier<'_>) -> Self {
        self.with_known_contracts(identifier.contracts())
    }

    /// Sets the verbosity level of the decoder.
    #[inline]
    pub fn with_verbosity(mut self, level: u8) -> Self {
        self.decoder.verbosity = level;
        self
    }

    /// Sets the signature identifier for events and functions.
    #[inline]
    pub fn with_signature_identifier(mut self, identifier: SingleSignaturesIdentifier) -> Self {
        self.decoder.signature_identifier = Some(identifier);
        self
    }

    /// Sets the debug identifier for the decoder.
    #[inline]
    pub fn with_debug_identifier(mut self, identifier: DebugTraceIdentifier) -> Self {
        self.decoder.debug_identifier = Some(identifier);
        self
    }

    /// Build the decoder.
    #[inline]
    pub fn build(self) -> CallTraceDecoder {
        self.decoder
    }
}

/// The call trace decoder.
///
/// The decoder collects address labels and ABIs from any number of [TraceIdentifier]s, which it
/// then uses to decode the call trace.
///
/// Note that a call trace decoder is required for each new set of traces, since addresses in
/// different sets might overlap.
#[derive(Clone, Debug, Default)]
pub struct CallTraceDecoder {
    /// Addresses identified to be a specific contract.
    ///
    /// The values are in the form `"<artifact>:<contract>"`.
    pub contracts: HashMap<Address, String>,
    /// Address labels.
    pub labels: HashMap<Address, String>,
    /// Contract addresses that have a receive function.
    pub receive_contracts: Vec<Address>,
    /// Contract addresses that have fallback functions, mapped to function sigs.
    pub fallback_contracts: HashMap<Address, Vec<String>>,

    /// All known functions.
    pub functions: HashMap<Selector, Vec<Function>>,
    /// All known events.
    pub events: BTreeMap<(B256, usize), Vec<Event>>,
    /// Revert decoder. Contains all known custom errors.
    pub revert_decoder: RevertDecoder,

    /// A signature identifier for events and functions.
    pub signature_identifier: Option<SingleSignaturesIdentifier>,
    /// Verbosity level
    pub verbosity: u8,

    /// Optional identifier of individual trace steps.
    pub debug_identifier: Option<DebugTraceIdentifier>,
}

impl CallTraceDecoder {
    /// Creates a new call trace decoder.
    ///
    /// The call trace decoder always knows how to decode calls to the cheatcode address, as well
    /// as DSTest-style logs.
    pub fn new() -> &'static Self {
        // If you want to take arguments in this function, assign them to the fields of the cloned
        // lazy instead of removing it
        static INIT: OnceLock<CallTraceDecoder> = OnceLock::new();
        INIT.get_or_init(Self::init)
    }

    fn init() -> Self {
        /// All functions from the Hardhat console ABI.
        ///
        /// See [`HARDHAT_CONSOLE_SELECTOR_PATCHES`] for more details.
        fn hh_funcs() -> impl Iterator<Item = (Selector, Function)> {
            let functions = HardhatConsole::abi::functions();
            let mut functions: Vec<_> =
                functions.into_values().flatten().map(|func| (func.selector(), func)).collect();
            let len = functions.len();
            // `functions` is the list of all patched functions; duplicate the unpatched ones
            for (unpatched, patched) in HARDHAT_CONSOLE_SELECTOR_PATCHES.iter() {
                if let Some((_, func)) = functions[..len].iter().find(|(sel, _)| sel == patched) {
                    functions.push((unpatched.into(), func.clone()));
                }
            }
            functions.into_iter()
        }

        Self {
            contracts: Default::default(),
            labels: HashMap::from_iter([
                (CHEATCODE_ADDRESS, "VM".to_string()),
                (HARDHAT_CONSOLE_ADDRESS, "console".to_string()),
                (DEFAULT_CREATE2_DEPLOYER, "Create2Deployer".to_string()),
                (CALLER, "DefaultSender".to_string()),
                (TEST_CONTRACT_ADDRESS, "DefaultTestContract".to_string()),
                (EC_RECOVER, "ECRecover".to_string()),
                (SHA_256, "SHA-256".to_string()),
                (RIPEMD_160, "RIPEMD-160".to_string()),
                (IDENTITY, "Identity".to_string()),
                (MOD_EXP, "ModExp".to_string()),
                (EC_ADD, "ECAdd".to_string()),
                (EC_MUL, "ECMul".to_string()),
                (EC_PAIRING, "ECPairing".to_string()),
                (BLAKE_2F, "Blake2F".to_string()),
                (POINT_EVALUATION, "PointEvaluation".to_string()),
            ]),
            receive_contracts: Default::default(),
            fallback_contracts: Default::default(),

            functions: hh_funcs()
                .chain(
                    Vm::abi::functions()
                        .into_values()
                        .flatten()
                        .map(|func| (func.selector(), func)),
                )
                .map(|(selector, func)| (selector, vec![func]))
                .collect(),
            events: Console::abi::events()
                .into_values()
                .flatten()
                .map(|event| ((event.selector(), indexed_inputs(&event)), vec![event]))
                .collect(),
            revert_decoder: Default::default(),

            signature_identifier: None,
            verbosity: 0,

            debug_identifier: None,
        }
    }

    /// Clears all known addresses.
    pub fn clear_addresses(&mut self) {
        self.contracts.clear();

        let default_labels = &Self::new().labels;
        if self.labels.len() > default_labels.len() {
            self.labels.clone_from(default_labels);
        }

        self.receive_contracts.clear();
        self.fallback_contracts.clear();
    }

    /// Identify unknown addresses in the specified call trace using the specified identifier.
    ///
    /// Unknown contracts are contracts that either lack a label or an ABI.
    pub fn identify(&mut self, trace: &CallTraceArena, identifier: &mut impl TraceIdentifier) {
        self.collect_identities(identifier.identify_addresses(self.trace_addresses(trace)));
    }

    /// Adds a single event to the decoder.
    pub fn push_event(&mut self, event: Event) {
        self.events.entry((event.selector(), indexed_inputs(&event))).or_default().push(event);
    }

    /// Adds a single function to the decoder.
    pub fn push_function(&mut self, function: Function) {
        match self.functions.entry(function.selector()) {
            Entry::Occupied(entry) => {
                // This shouldn't happen that often.
                if entry.get().contains(&function) {
                    return;
                }
                trace!(target: "evm::traces", selector=%entry.key(), new=%function.signature(), "duplicate function selector");
                entry.into_mut().push(function);
            }
            Entry::Vacant(entry) => {
                entry.insert(vec![function]);
            }
        }
    }

    /// Adds a single error to the decoder.
    pub fn push_error(&mut self, error: Error) {
        self.revert_decoder.push_error(error);
    }

    /// Returns an iterator over the trace addresses.
    pub fn trace_addresses<'a>(
        &'a self,
        arena: &'a CallTraceArena,
    ) -> impl Iterator<Item = (&'a Address, Option<&'a [u8]>, Option<&'a [u8]>)> + Clone + 'a {
        arena
            .nodes()
            .iter()
            .map(|node| {
                (
                    &node.trace.address,
                    node.trace.kind.is_any_create().then_some(&node.trace.output[..]),
                    node.trace.kind.is_any_create().then_some(&node.trace.data[..]),
                )
            })
            .filter(|&(address, _, _)| {
                !self.labels.contains_key(address) || !self.contracts.contains_key(address)
            })
    }

    fn collect_identities(&mut self, identities: Vec<AddressIdentity<'_>>) {
        // Skip logging if there are no identities.
        if identities.is_empty() {
            return;
        }

        trace!(target: "evm::traces", len=identities.len(), "collecting address identities");
        for AddressIdentity { address, label, contract, abi, artifact_id: _ } in identities {
            let _span = trace_span!(target: "evm::traces", "identity", ?contract, ?label).entered();

            if let Some(contract) = contract {
                self.contracts.entry(address).or_insert(contract);
            }

            if let Some(label) = label {
                self.labels.entry(address).or_insert(label);
            }

            if let Some(abi) = abi {
                self.collect_abi(&abi, Some(&address));
            }
        }
    }

    fn collect_abi(&mut self, abi: &JsonAbi, address: Option<&Address>) {
        trace!(target: "evm::traces", len=abi.len(), ?address, "collecting ABI");
        for function in abi.functions() {
            self.push_function(function.clone());
        }
        for event in abi.events() {
            self.push_event(event.clone());
        }
        for error in abi.errors() {
            self.push_error(error.clone());
        }
        if let Some(address) = address {
            if abi.receive.is_some() {
                self.receive_contracts.push(*address);
            }

            if abi.fallback.is_some() {
                let mut functions_sig = vec![];
                for function in abi.functions() {
                    functions_sig.push(function.signature());
                }
                self.fallback_contracts.insert(*address, functions_sig);
            }
        }
    }

    /// Populates the traces with decoded data by mutating the
    /// [CallTrace] in place. See [CallTraceDecoder::decode_function] and
    /// [CallTraceDecoder::decode_event] for more details.
    pub async fn populate_traces(&self, traces: &mut Vec<CallTraceNode>) {
        for node in traces {
            node.trace.decoded = self.decode_function(&node.trace).await;
            for log in node.logs.iter_mut() {
                log.decoded = self.decode_event(&log.raw_log).await;
            }

            if let Some(debug) = self.debug_identifier.as_ref() {
                if let Some(identified) = self.contracts.get(&node.trace.address) {
                    debug.identify_node_steps(node, get_contract_name(identified))
                }
            }
        }
    }

    /// Decodes a call trace.
    pub async fn decode_function(&self, trace: &CallTrace) -> DecodedCallTrace {
        if let Some(trace) = precompiles::decode(trace, 1) {
            return trace;
        }

        let label = self.labels.get(&trace.address).cloned();

        let cdata = &trace.data;
        if trace.address == DEFAULT_CREATE2_DEPLOYER {
            return DecodedCallTrace {
                label,
                call_data: Some(DecodedCallData { signature: "create2".to_string(), args: vec![] }),
                return_data: self.default_return_data(trace),
            };
        }

        if cdata.len() >= SELECTOR_LEN {
            let selector = &cdata[..SELECTOR_LEN];
            let mut functions = Vec::new();
            let functions = match self.functions.get(selector) {
                Some(fs) => fs,
                None => {
                    if let Some(identifier) = &self.signature_identifier {
                        if let Some(function) =
                            identifier.write().await.identify_function(selector).await
                        {
                            functions.push(function);
                        }
                    }
                    &functions
                }
            };
            let [func, ..] = &functions[..] else {
                return DecodedCallTrace {
                    label,
                    call_data: None,
                    return_data: self.default_return_data(trace),
                };
            };

            // If traced contract is a fallback contract, check if it has the decoded function.
            // If not, then replace call data signature with `fallback`.
            let mut call_data = self.decode_function_input(trace, func);
            if let Some(fallback_functions) = self.fallback_contracts.get(&trace.address) {
                if !fallback_functions.contains(&func.signature()) {
                    call_data.signature = "fallback()".into();
                }
            }

            DecodedCallTrace {
                label,
                call_data: Some(call_data),
                return_data: self.decode_function_output(trace, functions),
            }
        } else {
            let has_receive = self.receive_contracts.contains(&trace.address);
            let signature =
                if cdata.is_empty() && has_receive { "receive()" } else { "fallback()" }.into();
            let args = if cdata.is_empty() { Vec::new() } else { vec![cdata.to_string()] };
            DecodedCallTrace {
                label,
                call_data: Some(DecodedCallData { signature, args }),
                return_data: self.default_return_data(trace),
            }
        }
    }

    /// Decodes a function's input into the given trace.
    fn decode_function_input(&self, trace: &CallTrace, func: &Function) -> DecodedCallData {
        let mut args = None;
        if trace.data.len() >= SELECTOR_LEN {
            if trace.address == CHEATCODE_ADDRESS {
                // Try to decode cheatcode inputs in a more custom way
                if let Some(v) = self.decode_cheatcode_inputs(func, &trace.data) {
                    args = Some(v);
                }
            }

            if args.is_none() {
                if let Ok(v) = func.abi_decode_input(&trace.data[SELECTOR_LEN..], false) {
                    args = Some(v.iter().map(|value| self.format_value(value)).collect());
                }
            }
        }

        DecodedCallData { signature: func.signature(), args: args.unwrap_or_default() }
    }

    /// Custom decoding for cheatcode inputs.
    fn decode_cheatcode_inputs(&self, func: &Function, data: &[u8]) -> Option<Vec<String>> {
        match func.name.as_str() {
            "expectRevert" => Some(vec![self.revert_decoder.decode(data, None)]),
            "addr" | "createWallet" | "deriveKey" | "rememberKey" => {
                // Redact private key in all cases
                Some(vec!["<pk>".to_string()])
            }
            "broadcast" | "startBroadcast" => {
                // Redact private key if defined
                // broadcast(uint256) / startBroadcast(uint256)
                if !func.inputs.is_empty() && func.inputs[0].ty == "uint256" {
                    Some(vec!["<pk>".to_string()])
                } else {
                    None
                }
            }
            "getNonce" => {
                // Redact private key if defined
                // getNonce(Wallet)
                if !func.inputs.is_empty() && func.inputs[0].ty == "tuple" {
                    Some(vec!["<pk>".to_string()])
                } else {
                    None
                }
            }
            "sign" | "signP256" => {
                let mut decoded = func.abi_decode_input(&data[SELECTOR_LEN..], false).ok()?;

                // Redact private key and replace in trace
                // sign(uint256,bytes32) / signP256(uint256,bytes32) / sign(Wallet,bytes32)
                if !decoded.is_empty() &&
                    (func.inputs[0].ty == "uint256" || func.inputs[0].ty == "tuple")
                {
                    decoded[0] = DynSolValue::String("<pk>".to_string());
                }

                Some(decoded.iter().map(format_token).collect())
            }
            "parseJson" |
            "parseJsonUint" |
            "parseJsonUintArray" |
            "parseJsonInt" |
            "parseJsonIntArray" |
            "parseJsonString" |
            "parseJsonStringArray" |
            "parseJsonAddress" |
            "parseJsonAddressArray" |
            "parseJsonBool" |
            "parseJsonBoolArray" |
            "parseJsonBytes" |
            "parseJsonBytesArray" |
            "parseJsonBytes32" |
            "parseJsonBytes32Array" |
            "writeJson" |
            // `keyExists` is being deprecated in favor of `keyExistsJson`. It will be removed in future versions.
            "keyExists" | 
            "keyExistsJson" |
            "serializeBool" |
            "serializeUint" |
            "serializeUintToHex" |
            "serializeInt" |
            "serializeAddress" |
            "serializeBytes32" |
            "serializeString" |
            "serializeBytes" => {
                if self.verbosity >= 5 {
                    None
                } else {
                    let mut decoded = func.abi_decode_input(&data[SELECTOR_LEN..], false).ok()?;
                    let token = if func.name.as_str() == "parseJson" ||
                        // `keyExists` is being deprecated in favor of `keyExistsJson`. It will be removed in future versions.
                        func.name.as_str() == "keyExists" || 
                        func.name.as_str() == "keyExistsJson"
                    {
                        "<JSON file>"
                    } else {
                        "<stringified JSON>"
                    };
                    decoded[0] = DynSolValue::String(token.to_string());
                    Some(decoded.iter().map(format_token).collect())
                }
            }
            s if s.contains("Toml") => {
                if self.verbosity >= 5 {
                    None
                } else {
                    let mut decoded = func.abi_decode_input(&data[SELECTOR_LEN..], false).ok()?;
                    let token = if func.name.as_str() == "parseToml" ||
                        func.name.as_str() == "keyExistsToml"
                    {
                        "<TOML file>"
                    } else {
                        "<stringified TOML>"
                    };
                    decoded[0] = DynSolValue::String(token.to_string());
                    Some(decoded.iter().map(format_token).collect())
                }
            }
            "createFork" |
            "createSelectFork" |
            "rpc" => {
                let mut decoded = func.abi_decode_input(&data[SELECTOR_LEN..], false).ok()?;

                // Redact RPC URL except if referenced by an alias
                if !decoded.is_empty() && func.inputs[0].ty == "string" {
                    let url_or_alias = decoded[0].as_str().unwrap_or_default();

                    if url_or_alias.starts_with("http") || url_or_alias.starts_with("ws") {
                        decoded[0] = DynSolValue::String("<rpc url>".to_string());
                    }
                } else {
                    return None;
                }

                Some(decoded.iter().map(format_token).collect())
            }
            _ => None,
        }
    }

    /// Decodes a function's output into the given trace.
    fn decode_function_output(&self, trace: &CallTrace, funcs: &[Function]) -> Option<String> {
        if !trace.success {
            return self.default_return_data(trace);
        }

        if trace.address == CHEATCODE_ADDRESS {
            if let Some(decoded) = funcs.iter().find_map(|func| self.decode_cheatcode_outputs(func))
            {
                return Some(decoded);
            }
        }

        if let Some(values) =
            funcs.iter().find_map(|func| func.abi_decode_output(&trace.output, false).ok())
        {
            // Functions coming from an external database do not have any outputs specified,
            // and will lead to returning an empty list of values.
            if values.is_empty() {
                return None;
            }

            return Some(
                values.iter().map(|value| self.format_value(value)).format(", ").to_string(),
            );
        }

        None
    }

    /// Custom decoding for cheatcode outputs.
    fn decode_cheatcode_outputs(&self, func: &Function) -> Option<String> {
        match func.name.as_str() {
            s if s.starts_with("env") => Some("<env var value>"),
            "createWallet" | "deriveKey" => Some("<pk>"),
            "promptSecret" | "promptSecretUint" => Some("<secret>"),
            "parseJson" if self.verbosity < 5 => Some("<encoded JSON value>"),
            "readFile" if self.verbosity < 5 => Some("<file>"),
            "rpcUrl" | "rpcUrls" | "rpcUrlStructs" => Some("<rpc url>"),
            _ => None,
        }
        .map(Into::into)
    }

    /// The default decoded return data for a trace.
    fn default_return_data(&self, trace: &CallTrace) -> Option<String> {
        (!trace.success).then(|| self.revert_decoder.decode(&trace.output, Some(trace.status)))
    }

    /// Decodes an event.
    pub async fn decode_event(&self, log: &LogData) -> DecodedCallLog {
        let &[t0, ..] = log.topics() else { return DecodedCallLog { name: None, params: None } };

        let mut events = Vec::new();
        let events = match self.events.get(&(t0, log.topics().len() - 1)) {
            Some(es) => es,
            None => {
                if let Some(identifier) = &self.signature_identifier {
                    if let Some(event) = identifier.write().await.identify_event(&t0[..]).await {
                        events.push(get_indexed_event(event, log));
                    }
                }
                &events
            }
        };
        for event in events {
            if let Ok(decoded) = event.decode_log(log, false) {
                let params = reconstruct_params(event, &decoded);
                return DecodedCallLog {
                    name: Some(event.name.clone()),
                    params: Some(
                        params
                            .into_iter()
                            .zip(event.inputs.iter())
                            .map(|(param, input)| {
                                // undo patched names
                                let name = input.name.clone();
                                (name, self.format_value(&param))
                            })
                            .collect(),
                    ),
                };
            }
        }

        DecodedCallLog { name: None, params: None }
    }

    /// Prefetches function and event signatures into the identifier cache
    pub async fn prefetch_signatures(&self, nodes: &[CallTraceNode]) {
        let Some(identifier) = &self.signature_identifier else { return };

        let events_it = nodes
            .iter()
            .flat_map(|node| node.logs.iter().filter_map(|log| log.raw_log.topics().first()))
            .unique();
        identifier.write().await.identify_events(events_it).await;

        const DEFAULT_CREATE2_DEPLOYER_BYTES: [u8; 20] = DEFAULT_CREATE2_DEPLOYER.0 .0;
        let funcs_it = nodes
            .iter()
            .filter_map(|n| match n.trace.address.0 .0 {
                DEFAULT_CREATE2_DEPLOYER_BYTES => None,
                [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01..=0x0a] => None,
                _ => n.trace.data.get(..SELECTOR_LEN),
            })
            .filter(|v| !self.functions.contains_key(*v))
            .unique();
        identifier.write().await.identify_functions(funcs_it).await;
    }

    /// Pretty-prints a value.
    fn format_value(&self, value: &DynSolValue) -> String {
        if let DynSolValue::Address(addr) = value {
            if let Some(label) = self.labels.get(addr) {
                return format!("{label}: [{addr}]");
            }
        }
        format_token(value)
    }
}

/// Restore the order of the params of a decoded event,
/// as Alloy returns the indexed and unindexed params separately.
fn reconstruct_params(event: &Event, decoded: &DecodedEvent) -> Vec<DynSolValue> {
    let mut indexed = 0;
    let mut unindexed = 0;
    let mut inputs = vec![];
    for input in event.inputs.iter() {
        if input.indexed {
            inputs.push(decoded.indexed[indexed].clone());
            indexed += 1;
        } else {
            inputs.push(decoded.body[unindexed].clone());
            unindexed += 1;
        }
    }

    inputs
}

fn indexed_inputs(event: &Event) -> usize {
    event.inputs.iter().filter(|param| param.indexed).count()
}

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

    #[test]
    fn test_should_redact() {
        let decoder = CallTraceDecoder::new();

        // [function_signature, data, expected]
        let cheatcode_input_test_cases = vec![
            // Should redact private key from traces in all cases:
            ("addr(uint256)", vec![], Some(vec!["<pk>".to_string()])),
            ("createWallet(string)", vec![], Some(vec!["<pk>".to_string()])),
            ("createWallet(uint256)", vec![], Some(vec!["<pk>".to_string()])),
            ("deriveKey(string,uint32)", vec![], Some(vec!["<pk>".to_string()])),
            ("deriveKey(string,string,uint32)", vec![], Some(vec!["<pk>".to_string()])),
            ("deriveKey(string,uint32,string)", vec![], Some(vec!["<pk>".to_string()])),
            ("deriveKey(string,string,uint32,string)", vec![], Some(vec!["<pk>".to_string()])),
            ("rememberKey(uint256)", vec![], Some(vec!["<pk>".to_string()])),
            //
            // Should redact private key from traces in specific cases with exceptions:
            ("broadcast(uint256)", vec![], Some(vec!["<pk>".to_string()])),
            ("broadcast()", vec![], None), // Ignore: `private key` is not passed.
            ("startBroadcast(uint256)", vec![], Some(vec!["<pk>".to_string()])),
            ("startBroadcast()", vec![], None), // Ignore: `private key` is not passed.
            ("getNonce((address,uint256,uint256,uint256))", vec![], Some(vec!["<pk>".to_string()])),
            ("getNonce(address)", vec![], None), // Ignore: `address` is public.
            //
            // Should redact private key and replace in trace in cases:
            (
                "sign(uint256,bytes32)",
                hex!(
                    "
                    e341eaa4
                    7c852118294e51e653712a81e05800f419141751be58f605c371e15141b007a6
                    0000000000000000000000000000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec![
                    "\"<pk>\"".to_string(),
                    "0x0000000000000000000000000000000000000000000000000000000000000000"
                        .to_string(),
                ]),
            ),
            (
                "signP256(uint256,bytes32)",
                hex!(
                    "
                    83211b40
                    7c852118294e51e653712a81e05800f419141751be58f605c371e15141b007a6
                    0000000000000000000000000000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec![
                    "\"<pk>\"".to_string(),
                    "0x0000000000000000000000000000000000000000000000000000000000000000"
                        .to_string(),
                ]),
            ),
            (
                // cast calldata "createFork(string)" "https://eth-mainnet.g.alchemy.com/v2/api_key"
                "createFork(string)",
                hex!(
                    "
                    31ba3498
                    0000000000000000000000000000000000000000000000000000000000000020
                    000000000000000000000000000000000000000000000000000000000000002c
                    68747470733a2f2f6574682d6d61696e6e65742e672e616c6368656d792e636f
                    6d2f76322f6170695f6b65790000000000000000000000000000000000000000
                    "
                )
                .to_vec(),
                Some(vec!["\"<rpc url>\"".to_string()]),
            ),
            (
                // cast calldata "createFork(string)" "wss://eth-mainnet.g.alchemy.com/v2/api_key"
                "createFork(string)",
                hex!(
                    "
                    31ba3498
                    0000000000000000000000000000000000000000000000000000000000000020
                    000000000000000000000000000000000000000000000000000000000000002a
                    7773733a2f2f6574682d6d61696e6e65742e672e616c6368656d792e636f6d2f
                    76322f6170695f6b657900000000000000000000000000000000000000000000
                    "
                )
                .to_vec(),
                Some(vec!["\"<rpc url>\"".to_string()]),
            ),
            (
                // cast calldata "createFork(string)" "mainnet"
                "createFork(string)",
                hex!(
                    "
                    31ba3498
                    0000000000000000000000000000000000000000000000000000000000000020
                    0000000000000000000000000000000000000000000000000000000000000007
                    6d61696e6e657400000000000000000000000000000000000000000000000000
                    "
                )
                .to_vec(),
                Some(vec!["\"mainnet\"".to_string()]),
            ),
            (
                // cast calldata "createFork(string,uint256)" "https://eth-mainnet.g.alchemy.com/v2/api_key" 1
                "createFork(string,uint256)",
                hex!(
                    "
                    6ba3ba2b
                    0000000000000000000000000000000000000000000000000000000000000040
                    0000000000000000000000000000000000000000000000000000000000000001
                    000000000000000000000000000000000000000000000000000000000000002c
                    68747470733a2f2f6574682d6d61696e6e65742e672e616c6368656d792e636f
                    6d2f76322f6170695f6b65790000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec!["\"<rpc url>\"".to_string(), "1".to_string()]),
            ),
            (
                // cast calldata "createFork(string,uint256)" "mainnet" 1
                "createFork(string,uint256)",
                hex!(
                    "
                    6ba3ba2b
                    0000000000000000000000000000000000000000000000000000000000000040
                    0000000000000000000000000000000000000000000000000000000000000001
                    0000000000000000000000000000000000000000000000000000000000000007
                    6d61696e6e657400000000000000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec!["\"mainnet\"".to_string(), "1".to_string()]),
            ),
            (
                // cast calldata "createFork(string,bytes32)" "https://eth-mainnet.g.alchemy.com/v2/api_key" 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
                "createFork(string,bytes32)",
                hex!(
                    "
                    7ca29682
                    0000000000000000000000000000000000000000000000000000000000000040
                    ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
                    000000000000000000000000000000000000000000000000000000000000002c
                    68747470733a2f2f6574682d6d61696e6e65742e672e616c6368656d792e636f
                    6d2f76322f6170695f6b65790000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec![
                    "\"<rpc url>\"".to_string(),
                    "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
                        .to_string(),
                ]),
            ),
            (
                // cast calldata "createFork(string,bytes32)" "mainnet"
                // 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
                "createFork(string,bytes32)",
                hex!(
                    "
                    7ca29682
                    0000000000000000000000000000000000000000000000000000000000000040
                    ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
                    0000000000000000000000000000000000000000000000000000000000000007
                    6d61696e6e657400000000000000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec![
                    "\"mainnet\"".to_string(),
                    "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
                        .to_string(),
                ]),
            ),
            (
                // cast calldata "createSelectFork(string)" "https://eth-mainnet.g.alchemy.com/v2/api_key"
                "createSelectFork(string)",
                hex!(
                    "
                    98680034
                    0000000000000000000000000000000000000000000000000000000000000020
                    000000000000000000000000000000000000000000000000000000000000002c
                    68747470733a2f2f6574682d6d61696e6e65742e672e616c6368656d792e636f
                    6d2f76322f6170695f6b65790000000000000000000000000000000000000000
                    "
                )
                .to_vec(),
                Some(vec!["\"<rpc url>\"".to_string()]),
            ),
            (
                // cast calldata "createSelectFork(string)" "mainnet"
                "createSelectFork(string)",
                hex!(
                    "
                    98680034
                    0000000000000000000000000000000000000000000000000000000000000020
                    0000000000000000000000000000000000000000000000000000000000000007
                    6d61696e6e657400000000000000000000000000000000000000000000000000
                    "
                )
                .to_vec(),
                Some(vec!["\"mainnet\"".to_string()]),
            ),
            (
                // cast calldata "createSelectFork(string,uint256)" "https://eth-mainnet.g.alchemy.com/v2/api_key" 1
                "createSelectFork(string,uint256)",
                hex!(
                    "
                    71ee464d
                    0000000000000000000000000000000000000000000000000000000000000040
                    0000000000000000000000000000000000000000000000000000000000000001
                    000000000000000000000000000000000000000000000000000000000000002c
                    68747470733a2f2f6574682d6d61696e6e65742e672e616c6368656d792e636f
                    6d2f76322f6170695f6b65790000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec!["\"<rpc url>\"".to_string(), "1".to_string()]),
            ),
            (
                // cast calldata "createSelectFork(string,uint256)" "mainnet" 1
                "createSelectFork(string,uint256)",
                hex!(
                    "
                    71ee464d
                    0000000000000000000000000000000000000000000000000000000000000040
                    0000000000000000000000000000000000000000000000000000000000000001
                    0000000000000000000000000000000000000000000000000000000000000007
                    6d61696e6e657400000000000000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec!["\"mainnet\"".to_string(), "1".to_string()]),
            ),
            (
                // cast calldata "createSelectFork(string,bytes32)" "https://eth-mainnet.g.alchemy.com/v2/api_key" 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
                "createSelectFork(string,bytes32)",
                hex!(
                    "
                    84d52b7a
                    0000000000000000000000000000000000000000000000000000000000000040
                    ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
                    000000000000000000000000000000000000000000000000000000000000002c
                    68747470733a2f2f6574682d6d61696e6e65742e672e616c6368656d792e636f
                    6d2f76322f6170695f6b65790000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec![
                    "\"<rpc url>\"".to_string(),
                    "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
                        .to_string(),
                ]),
            ),
            (
                // cast calldata "createSelectFork(string,bytes32)" "mainnet"
                // 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
                "createSelectFork(string,bytes32)",
                hex!(
                    "
                    84d52b7a
                    0000000000000000000000000000000000000000000000000000000000000040
                    ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
                    0000000000000000000000000000000000000000000000000000000000000007
                    6d61696e6e657400000000000000000000000000000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec![
                    "\"mainnet\"".to_string(),
                    "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
                        .to_string(),
                ]),
            ),
            (
                // cast calldata "rpc(string,string,string)" "https://eth-mainnet.g.alchemy.com/v2/api_key" "eth_getBalance" "[\"0x551e7784778ef8e048e495df49f2614f84a4f1dc\",\"0x0\"]"
                "rpc(string,string,string)",
                hex!(
                    "
                    0199a220
                    0000000000000000000000000000000000000000000000000000000000000060
                    00000000000000000000000000000000000000000000000000000000000000c0
                    0000000000000000000000000000000000000000000000000000000000000100
                    000000000000000000000000000000000000000000000000000000000000002c
                    68747470733a2f2f6574682d6d61696e6e65742e672e616c6368656d792e636f
                    6d2f76322f6170695f6b65790000000000000000000000000000000000000000
                    000000000000000000000000000000000000000000000000000000000000000e
                    6574685f67657442616c616e6365000000000000000000000000000000000000
                    0000000000000000000000000000000000000000000000000000000000000034
                    5b22307835353165373738343737386566386530343865343935646634396632
                    363134663834613466316463222c22307830225d000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec![
                    "\"<rpc url>\"".to_string(),
                    "\"eth_getBalance\"".to_string(),
                    "\"[\\\"0x551e7784778ef8e048e495df49f2614f84a4f1dc\\\",\\\"0x0\\\"]\""
                        .to_string(),
                ]),
            ),
            (
                // cast calldata "rpc(string,string,string)" "mainnet" "eth_getBalance"
                // "[\"0x551e7784778ef8e048e495df49f2614f84a4f1dc\",\"0x0\"]"
                "rpc(string,string,string)",
                hex!(
                    "
                    0199a220
                    0000000000000000000000000000000000000000000000000000000000000060
                    00000000000000000000000000000000000000000000000000000000000000a0
                    00000000000000000000000000000000000000000000000000000000000000e0
                    0000000000000000000000000000000000000000000000000000000000000007
                    6d61696e6e657400000000000000000000000000000000000000000000000000
                    000000000000000000000000000000000000000000000000000000000000000e
                    6574685f67657442616c616e6365000000000000000000000000000000000000
                    0000000000000000000000000000000000000000000000000000000000000034
                    5b22307835353165373738343737386566386530343865343935646634396632
                    363134663834613466316463222c22307830225d000000000000000000000000
                "
                )
                .to_vec(),
                Some(vec![
                    "\"mainnet\"".to_string(),
                    "\"eth_getBalance\"".to_string(),
                    "\"[\\\"0x551e7784778ef8e048e495df49f2614f84a4f1dc\\\",\\\"0x0\\\"]\""
                        .to_string(),
                ]),
            ),
        ];

        // [function_signature, expected]
        let cheatcode_output_test_cases = vec![
            // Should redact private key on output in all cases:
            ("createWallet(string)", Some("<pk>".to_string())),
            ("deriveKey(string,uint32)", Some("<pk>".to_string())),
            // Should redact RPC URL if defined, except if referenced by an alias:
            ("rpcUrl(string)", Some("<rpc url>".to_string())),
            ("rpcUrls()", Some("<rpc url>".to_string())),
            ("rpcUrlStructs()", Some("<rpc url>".to_string())),
        ];

        for (function_signature, data, expected) in cheatcode_input_test_cases {
            let function = Function::parse(function_signature).unwrap();
            let result = decoder.decode_cheatcode_inputs(&function, &data);
            assert_eq!(result, expected, "Input case failed for: {function_signature}");
        }

        for (function_signature, expected) in cheatcode_output_test_cases {
            let function = Function::parse(function_signature).unwrap();
            let result = Some(decoder.decode_cheatcode_outputs(&function).unwrap_or_default());
            assert_eq!(result, expected, "Output case failed for: {function_signature}");
        }
    }
}