fix(forge): enable fail fast flag

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

@@ -1,4 +1,6 @@
-use crate::executors::{DURATION_BETWEEN_METRICS_REPORT, Executor, FuzzTestTimer, RawCallResult};
+use crate::executors::{
+    DURATION_BETWEEN_METRICS_REPORT, Executor, FailFast, FuzzTestTimer, RawCallResult,
+};
 use alloy_dyn_abi::JsonAbiExt;
 use alloy_json_abi::Function;
 use alloy_primitives::{Address, Bytes, Log, U256, map::HashMap};
@@ -90,6 +92,7 @@ impl FuzzedExecutor {
     /// test case.
     ///
     /// Returns a list of all the consumed gas and calldata of every fuzz case.
+    #[allow(clippy::too_many_arguments)]
     pub fn fuzz(
         &mut self,
         func: &Function,
@@ -98,6 +101,7 @@ impl FuzzedExecutor {
         address: Address,
         rd: &RevertDecoder,
         progress: Option<&ProgressBar>,
+        fail_fast: &FailFast,
     ) -> Result<FuzzTestResult> {
         // Stores the fuzz test execution data.
         let mut test_data = FuzzTestData::default();
@@ -128,6 +132,10 @@ impl FuzzedExecutor {
         let mut last_metrics_report = Instant::now();
         let max_runs = self.config.runs;
         let continue_campaign = |runs: u32| {
+            if fail_fast.should_stop() {
+                return false;
+            }
+
             if timer.is_enabled() { !timer.is_timed_out() } else { runs < max_runs }
         };
 

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

@@ -49,7 +49,7 @@ use serde_json::json;
 
 mod shrink;
 use crate::executors::{
-    DURATION_BETWEEN_METRICS_REPORT, EvmError, FuzzTestTimer, corpus::CorpusManager,
+    DURATION_BETWEEN_METRICS_REPORT, EvmError, FailFast, FuzzTestTimer, corpus::CorpusManager,
 };
 pub use shrink::check_sequence;
 
@@ -327,6 +327,7 @@ impl<'a> InvariantExecutor<'a> {
         fuzz_fixtures: &FuzzFixtures,
         deployed_libs: &[Address],
         progress: Option<&ProgressBar>,
+        fail_fast: &FailFast,
     ) -> Result<InvariantFuzzTestResult> {
         // Throw an error to abort test run if the invariant function accepts input params
         if !invariant_contract.invariant_function.inputs.is_empty() {
@@ -341,6 +342,10 @@ impl<'a> InvariantExecutor<'a> {
         let timer = FuzzTestTimer::new(self.config.timeout);
         let mut last_metrics_report = Instant::now();
         let continue_campaign = |runs: u32| {
+            if fail_fast.should_stop() {
+                return false;
+            }
+
             if timer.is_enabled() { !timer.is_timed_out() } else { runs < self.config.runs }
         };
 

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

@@ -44,6 +44,10 @@ use revm::{
 };
 use std::{
     borrow::Cow,
+    sync::{
+        Arc,
+        atomic::{AtomicBool, Ordering},
+    },
     time::{Duration, Instant},
 };
 
@@ -1109,3 +1113,34 @@ impl FuzzTestTimer {
         self.inner.is_some_and(|(start, duration)| start.elapsed() > duration)
     }
 }
+
+/// Helper struct to enable fail fast behavior: when one test fails, all other tests stop early.
+#[derive(Clone)]
+pub struct FailFast {
+    /// Shared atomic flag set to `true` when a failure occurs.
+    /// None if fail-fast is disabled.
+    inner: Option<Arc<AtomicBool>>,
+}
+
+impl FailFast {
+    pub fn new(fail_fast: bool) -> Self {
+        Self { inner: fail_fast.then_some(Arc::new(AtomicBool::new(false))) }
+    }
+
+    /// Returns `true` if fail-fast is enabled.
+    pub fn is_enabled(&self) -> bool {
+        self.inner.is_some()
+    }
+
+    /// Sets the failure flag. Used by other tests to stop early.
+    pub fn record_fail(&self) {
+        if let Some(fail_fast) = &self.inner {
+            fail_fast.store(true, Ordering::Relaxed);
+        }
+    }
+
+    /// Whether a failure has been recorded and test should stop.
+    pub fn should_stop(&self) -> bool {
+        self.inner.as_ref().map(|flag| flag.load(Ordering::Relaxed)).unwrap_or(false)
+    }
+}

crates/forge/src/cmd/test/mod.rs

@@ -355,6 +355,7 @@ impl TestArgs {
             .sender(evm_opts.sender)
             .with_fork(evm_opts.get_fork(&config, env.clone()))
             .enable_isolation(evm_opts.isolate)
+            .fail_fast(self.fail_fast)
             .odyssey(evm_opts.odyssey)
             .build::<MultiCompiler>(project_root, &output, env, evm_opts)?;
 

crates/forge/src/multi_runner.rs

@@ -18,7 +18,7 @@ use foundry_evm::{
     Env,
     backend::Backend,
     decode::RevertDecoder,
-    executors::{Executor, ExecutorBuilder},
+    executors::{Executor, ExecutorBuilder, FailFast},
     fork::CreateFork,
     inspectors::CheatsConfig,
     opts::EvmOpts,
@@ -296,6 +296,8 @@ pub struct TestRunnerConfig {
     pub isolation: bool,
     /// Whether to enable Odyssey features.
     pub odyssey: bool,
+    /// Whether to exit early on test failure.
+    pub fail_fast: FailFast,
 }
 
 impl TestRunnerConfig {
@@ -404,6 +406,8 @@ pub struct MultiContractRunnerBuilder {
     pub isolation: bool,
     /// Whether to enable Odyssey features.
     pub odyssey: bool,
+    /// Whether to exit early on test failure.
+    pub fail_fast: bool,
 }
 
 impl MultiContractRunnerBuilder {
@@ -419,6 +423,7 @@ impl MultiContractRunnerBuilder {
             isolation: Default::default(),
             decode_internal: Default::default(),
             odyssey: Default::default(),
+            fail_fast: false,
         }
     }
 
@@ -457,6 +462,11 @@ impl MultiContractRunnerBuilder {
         self
     }
 
+    pub fn fail_fast(mut self, fail_fast: bool) -> Self {
+        self.fail_fast = fail_fast;
+        self
+    }
+
     pub fn enable_isolation(mut self, enable: bool) -> Self {
         self.isolation = enable;
         self
@@ -538,15 +548,14 @@ impl MultiContractRunnerBuilder {
                 env,
                 spec_id: self.evm_spec.unwrap_or_else(|| self.config.evm_spec_id()),
                 sender: self.sender.unwrap_or(self.config.sender),
-
                 line_coverage: self.line_coverage,
                 debug: self.debug,
                 decode_internal: self.decode_internal,
                 inline_config: Arc::new(InlineConfig::new_parsed(output, &self.config)?),
                 isolation: self.isolation,
                 odyssey: self.odyssey,
-
                 config: self.config,
+                fail_fast: FailFast::new(self.fail_fast),
             },
         })
     }

crates/forge/src/runner.rs

@@ -401,9 +401,16 @@ impl<'a> ContractRunner<'a> {
             return SuiteResult::new(start.elapsed(), [(instances, fail)].into(), warnings);
         }
 
+        let fail_fast = &self.tcfg.fail_fast;
+
         let test_results = functions
             .par_iter()
             .map(|&func| {
+                // Early exit if we're running with fail-fast and a test already failed.
+                if fail_fast.should_stop() {
+                    return (func.signature(), TestResult::setup_result(setup.clone()));
+                }
+
                 let start = Instant::now();
 
                 let _guard = self.tokio_handle.enter();
@@ -432,6 +439,11 @@ impl<'a> ContractRunner<'a> {
                 );
                 res.duration = start.elapsed();
 
+                // Set fail fast flag if current test failed.
+                if res.status.is_failure() {
+                    fail_fast.record_fail();
+                }
+
                 (sig, res)
             })
             .collect::<BTreeMap<_, _>>();
@@ -629,6 +641,10 @@ impl<'a> FunctionRunner<'a> {
         );
 
         for i in 0..fixtures_len {
+            if self.tcfg.fail_fast.should_stop() {
+                return self.result;
+            }
+
             // Increment progress bar.
             if let Some(progress) = progress.as_ref() {
                 progress.inc(1);
@@ -800,6 +816,7 @@ impl<'a> FunctionRunner<'a> {
             &self.setup.fuzz_fixtures,
             &self.setup.deployed_libs,
             progress.as_ref(),
+            &self.tcfg.fail_fast,
         ) {
             Ok(x) => x,
             Err(e) => {
@@ -950,6 +967,7 @@ impl<'a> FunctionRunner<'a> {
             self.address,
             &self.cr.mcr.revert_decoder,
             progress.as_ref(),
+            &self.tcfg.fail_fast,
         ) {
             Ok(x) => x,
             Err(e) => {

crates/forge/tests/cli/config.rs

@@ -1878,3 +1878,47 @@ forgetest_init!(test_exclude_lints_config, |prj, cmd| {
     });
     cmd.args(["lint"]).assert_success().stdout_eq(str![""]);
 });
+
+// <https://github.com/foundry-rs/foundry/issues/6529>
+forgetest_init!(test_fail_fast_config, |prj, cmd| {
+    prj.update_config(|config| {
+        // Set large timeout for fuzzed tests so test campaign won't stop if fail fast not passed.
+        config.fuzz.timeout = Some(3600);
+        config.invariant.timeout = Some(3600);
+    });
+    prj.add_test(
+        "AnotherCounterTest.sol",
+        r#"
+import {Test} from "forge-std/Test.sol";
+
+contract InvariantHandler is Test {
+    function fuzz_selector(uint256 x) public {
+    }
+}
+
+contract AnotherCounterTest is Test {
+    uint256[] public fixtureAmount = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+
+    function setUp() public {
+        new InvariantHandler();
+    }
+    // This failure should stop all other tests.
+    function test_Failure() public pure {
+        require(false);
+    }
+
+    function testFuzz_SetNumber(uint256 x) public {
+    }
+
+    function invariant_SetNumber() public {
+    }
+
+    function table_SetNumber(uint256 amount) public {
+        require(amount < 100);
+    }
+}
+"#,
+    )
+    .unwrap();
+    cmd.args(["test", "--fail-fast"]).assert_failure();
+});