feat(fuzz): ability to declare fuzz test fixtures

crates/common/src/traits.rs

@@ -33,6 +33,9 @@ pub trait TestFunctionExt {
 
     /// Returns whether this function is a `setUp` function.
     fn is_setup(&self) -> bool;
+
+    /// Returns whether this function is a `fixture` function.
+    fn is_fixture(&self) -> bool;
 }
 
 impl TestFunctionExt for Function {
@@ -56,6 +59,10 @@ impl TestFunctionExt for Function {
     fn is_setup(&self) -> bool {
         self.name.is_setup()
     }
+
+    fn is_fixture(&self) -> bool {
+        self.name.is_fixture()
+    }
 }
 
 impl TestFunctionExt for String {
@@ -78,6 +85,10 @@ impl TestFunctionExt for String {
     fn is_setup(&self) -> bool {
         self.as_str().is_setup()
     }
+
+    fn is_fixture(&self) -> bool {
+        self.as_str().is_fixture()
+    }
 }
 
 impl TestFunctionExt for str {
@@ -100,6 +111,10 @@ impl TestFunctionExt for str {
     fn is_setup(&self) -> bool {
         self.eq_ignore_ascii_case("setup")
     }
+
+    fn is_fixture(&self) -> bool {
+        self.starts_with("fixture_")
+    }
 }
 
 /// An extension trait for `std::error::Error` for ABI encoding.

crates/config/src/fuzz.rs

@@ -111,10 +111,6 @@ pub struct FuzzDictionaryConfig {
     /// Once the fuzzer exceeds this limit, it will start evicting random entries
     #[serde(deserialize_with = "crate::deserialize_usize_or_max")]
     pub max_fuzz_dictionary_values: usize,
-    /// How many random addresses to use and to recycle when fuzzing calldata.
-    /// If not specified then `max_fuzz_dictionary_addresses` value applies.
-    #[serde(deserialize_with = "crate::deserialize_usize_or_max")]
-    pub max_calldata_fuzz_dictionary_addresses: usize,
 }
 
 impl Default for FuzzDictionaryConfig {
@@ -127,7 +123,6 @@ impl Default for FuzzDictionaryConfig {
             max_fuzz_dictionary_addresses: (300 * 1024 * 1024) / 20,
             // limit this to 200MB
             max_fuzz_dictionary_values: (200 * 1024 * 1024) / 32,
-            max_calldata_fuzz_dictionary_addresses: 0,
         }
     }
 }

crates/evm/evm/src/executors/fuzz/mod.rs

@@ -14,7 +14,7 @@ use foundry_evm_fuzz::{
         build_initial_state, collect_state_from_call, fuzz_calldata, fuzz_calldata_from_state,
         EvmFuzzState,
     },
-    BaseCounterExample, CounterExample, FuzzCase, FuzzError, FuzzTestResult,
+    BaseCounterExample, CounterExample, FuzzCase, FuzzError, FuzzFixtures, FuzzTestResult,
 };
 use foundry_evm_traces::CallTraceArena;
 use proptest::test_runner::{TestCaseError, TestError, TestRunner};
@@ -58,6 +58,7 @@ impl FuzzedExecutor {
     pub fn fuzz(
         &self,
         func: &Function,
+        fuzz_fixtures: &FuzzFixtures,
         address: Address,
         should_fail: bool,
         rd: &RevertDecoder,
@@ -83,10 +84,12 @@ impl FuzzedExecutor {
         let state = self.build_fuzz_state();
 
         let dictionary_weight = self.config.dictionary.dictionary_weight.min(100);
+
         let strat = proptest::prop_oneof![
-            100 - dictionary_weight => fuzz_calldata(func.clone()),
+            100 - dictionary_weight => fuzz_calldata(func.clone(), fuzz_fixtures),
             dictionary_weight => fuzz_calldata_from_state(func.clone(), &state),
         ];
+
         debug!(func=?func.name, should_fail, "fuzzing");
         let run_result = self.runner.clone().run(&strat, |calldata| {
             let fuzz_res = self.single_fuzz(&state, address, should_fail, calldata)?;

crates/evm/evm/src/executors/invariant/mod.rs

@@ -18,14 +18,14 @@ use foundry_evm_fuzz::{
     },
     strategies::{
         build_initial_state, collect_created_contracts, collect_state_from_call, invariant_strat,
-        override_call_strat, CalldataFuzzDictionary, EvmFuzzState,
+        override_call_strat, EvmFuzzState,
     },
-    FuzzCase, FuzzedCases,
+    FuzzCase, FuzzFixtures, FuzzedCases,
 };
 use foundry_evm_traces::CallTraceArena;
 use parking_lot::{Mutex, RwLock};
 use proptest::{
-    strategy::{BoxedStrategy, Strategy, ValueTree},
+    strategy::{BoxedStrategy, Strategy},
     test_runner::{TestCaseError, TestRunner},
 };
 use revm::{primitives::HashMap, DatabaseCommit};
@@ -88,12 +88,8 @@ sol! {
 }
 
 /// Alias for (Dictionary for fuzzing, initial contracts to fuzz and an InvariantStrategy).
-type InvariantPreparation = (
-    EvmFuzzState,
-    FuzzRunIdentifiedContracts,
-    BoxedStrategy<BasicTxDetails>,
-    CalldataFuzzDictionary,
-);
+type InvariantPreparation =
+    (EvmFuzzState, FuzzRunIdentifiedContracts, BoxedStrategy<BasicTxDetails>);
 
 /// Enriched results of an invariant run check.
 ///
@@ -152,14 +148,15 @@ impl<'a> InvariantExecutor<'a> {
     pub fn invariant_fuzz(
         &mut self,
         invariant_contract: InvariantContract<'_>,
+        fuzz_fixtures: &FuzzFixtures,
     ) -> Result<InvariantFuzzTestResult> {
         // Throw an error to abort test run if the invariant function accepts input params
         if !invariant_contract.invariant_function.inputs.is_empty() {
             return Err(eyre!("Invariant test function should have no inputs"))
         }
 
-        let (fuzz_state, targeted_contracts, strat, calldata_fuzz_dictionary) =
-            self.prepare_fuzzing(&invariant_contract)?;
+        let (fuzz_state, targeted_contracts, strat) =
+            self.prepare_fuzzing(&invariant_contract, fuzz_fixtures)?;
 
         // Stores the consumed gas and calldata of every successful fuzz call.
         let fuzz_cases: RefCell<Vec<FuzzedCases>> = RefCell::new(Default::default());
@@ -328,7 +325,7 @@ impl<'a> InvariantExecutor<'a> {
             Ok(())
         });
 
-        trace!(target: "forge::test::invariant::calldata_address_fuzz_dictionary", "{:?}", calldata_fuzz_dictionary.inner.addresses);
+        trace!(target: "forge::test::invariant::fuzz_fixtures", "{:?}", fuzz_fixtures);
         trace!(target: "forge::test::invariant::dictionary", "{:?}", fuzz_state.read().values().iter().map(hex::encode).collect::<Vec<_>>());
 
         let (reverts, error) = failures.into_inner().into_inner();
@@ -349,6 +346,7 @@ impl<'a> InvariantExecutor<'a> {
     fn prepare_fuzzing(
         &mut self,
         invariant_contract: &InvariantContract<'_>,
+        fuzz_fixtures: &FuzzFixtures,
     ) -> eyre::Result<InvariantPreparation> {
         // Finds out the chosen deployed contracts and/or senders.
         self.select_contract_artifacts(invariant_contract.address)?;
@@ -368,16 +366,13 @@ impl<'a> InvariantExecutor<'a> {
         let targeted_contracts: FuzzRunIdentifiedContracts =
             Arc::new(Mutex::new(targeted_contracts));
 
-        let calldata_fuzz_config =
-            CalldataFuzzDictionary::new(&self.config.dictionary, &fuzz_state);
-
         // Creates the invariant strategy.
         let strat = invariant_strat(
             fuzz_state.clone(),
             targeted_senders,
             targeted_contracts.clone(),
             self.config.dictionary.dictionary_weight,
-            calldata_fuzz_config.clone(),
+            fuzz_fixtures.clone(),
         )
         .no_shrink()
         .boxed();
@@ -395,7 +390,7 @@ impl<'a> InvariantExecutor<'a> {
                     fuzz_state.clone(),
                     targeted_contracts.clone(),
                     target_contract_ref.clone(),
-                    calldata_fuzz_config.clone(),
+                    fuzz_fixtures.clone(),
                 ),
                 target_contract_ref,
             ));
@@ -404,7 +399,7 @@ impl<'a> InvariantExecutor<'a> {
         self.executor.inspector.fuzzer =
             Some(Fuzzer { call_generator, fuzz_state: fuzz_state.clone(), collect: true });
 
-        Ok((fuzz_state, targeted_contracts, strat, calldata_fuzz_config))
+        Ok((fuzz_state, targeted_contracts, strat))
     }
 
     /// Fills the `InvariantExecutor` with the artifact identifier filters (in `path:name` string

crates/evm/fuzz/src/lib.rs

@@ -14,7 +14,7 @@ use foundry_evm_coverage::HitMaps;
 use foundry_evm_traces::CallTraceArena;
 use itertools::Itertools;
 use serde::{Deserialize, Serialize};
-use std::{collections::HashMap, fmt};
+use std::{collections::HashMap, fmt, sync::Arc};
 
 pub use proptest::test_runner::{Config as FuzzConfig, Reason};
 
@@ -272,3 +272,27 @@ impl FuzzedCases {
         self.lowest().map(|c| c.gas).unwrap_or_default()
     }
 }
+
+/// Fixtures to be used for fuzz tests.
+/// The key represents name of the fuzzed parameter, value holds possible fuzzed values.
+/// For example, for a fixture function declared as
+/// `function fixture_sender() external returns (address[] memory senders)`
+/// the fuzz fixtures will contain `sender` key with `senders` array as value
+#[derive(Clone, Default, Debug)]
+pub struct FuzzFixtures {
+    inner: Arc<HashMap<String, DynSolValue>>,
+}
+
+impl FuzzFixtures {
+    pub fn new(fixtures: HashMap<String, DynSolValue>) -> FuzzFixtures {
+        Self { inner: Arc::new(fixtures) }
+    }
+
+    pub fn param_fixtures(&self, param_name: &String) -> Option<&[DynSolValue]> {
+        if let Some(param_fixtures) = self.inner.get(param_name) {
+            param_fixtures.as_array()
+        } else {
+            None
+        }
+    }
+}

crates/evm/fuzz/src/strategies/address.rs

@@ -0,0 +1,53 @@
+use alloy_dyn_abi::DynSolValue;
+use alloy_primitives::Address;
+use proptest::{
+    arbitrary::any,
+    prelude::{prop, BoxedStrategy},
+    strategy::Strategy,
+};
+
+/// The address strategy combines 2 different strategies:
+/// 1. A random addresses strategy if no fixture defined for current parameter.
+/// 2. A fixture based strategy if configured values for current parameters.
+/// If fixture is not a valid type then an error is raised and test suite will continue to execute
+/// with random address.
+///
+///
+/// For example:
+/// To define fixture for `owner` fuzzed parameter, return an array of possible values from
+/// `function fixture_owner() public returns (address[] memory)`.
+/// Use `owner` named parameter in fuzzed test in order to create a custom strategy
+/// `function testFuzz_ownerAddress(address owner, uint amount)`.
+#[derive(Debug)]
+pub struct AddressStrategy {}
+
+impl AddressStrategy {
+    /// Create a new address strategy.
+    pub fn init(fixtures: Option<&[DynSolValue]>) -> BoxedStrategy<DynSolValue> {
+        if let Some(fixtures) = fixtures {
+            let address_fixtures: Vec<DynSolValue> =
+                fixtures.iter().enumerate().map(|(_, value)| value.to_owned()).collect();
+            let address_fixtures_len = address_fixtures.len();
+            any::<prop::sample::Index>()
+                .prop_map(move |index| {
+                    // Generate value tree from fixture.
+                    // If fixture is not a valid address, raise error and generate random value.
+                    let index = index.index(address_fixtures_len);
+                    if let Some(addr_fixture) = address_fixtures.get(index) {
+                        if let Some(addr_fixture) = addr_fixture.as_address() {
+                            return DynSolValue::Address(addr_fixture);
+                        }
+                    }
+                    error!(
+                        "{:?} is not a valid address fixture, generate random value",
+                        address_fixtures.get(index)
+                    );
+                    DynSolValue::Address(Address::random())
+                })
+                .boxed()
+        } else {
+            // If no config for addresses dictionary then create unbounded addresses strategy.
+            any::<Address>().prop_map(DynSolValue::Address).boxed()
+        }
+    }
+}