fix: enable edge coverage only when needed (foundry-rs#11041)

* fix: enable edge coverage inspector only if corpus set

* Add show edge coveerage setting, enable inspector per invariant test

Author: grandizzy

crates/config/src/invariant.rs

@@ -26,8 +26,8 @@ pub struct InvariantConfig {
     pub max_assume_rejects: u32,
     /// Number of runs to execute and include in the gas report.
     pub gas_report_samples: u32,
-    /// Path where invariant corpus is stored. If not configured then coverage guided fuzzing is
-    /// disabled.
+    /// Path where invariant corpus is stored, enables coverage guided fuzzing and edge coverage
+    /// metrics.
     pub corpus_dir: Option<PathBuf>,
     /// Whether corpus to use gzip file compression and decompression.
     pub corpus_gzip: bool,
@@ -43,6 +43,8 @@ pub struct InvariantConfig {
     pub timeout: Option<u32>,
     /// Display counterexample as solidity calls.
     pub show_solidity: bool,
+    /// Whether to collect and display edge coverage metrics.
+    pub show_edge_coverage: bool,
 }
 
 impl Default for InvariantConfig {
@@ -64,6 +66,7 @@ impl Default for InvariantConfig {
             show_metrics: true,
             timeout: None,
             show_solidity: false,
+            show_edge_coverage: false,
         }
     }
 }
@@ -88,6 +91,7 @@ impl InvariantConfig {
             show_metrics: true,
             timeout: None,
             show_solidity: false,
+            show_edge_coverage: false,
         }
     }
 }

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

@@ -357,6 +357,10 @@ impl<'a> InvariantExecutor<'a> {
             runs < self.config.runs
         };
 
+        // Invariant runs with edge coverage if corpus dir is set or showing edge coverage.
+        let edge_coverage_enabled =
+            self.config.corpus_dir.is_some() || self.config.show_edge_coverage;
+
         'stop: while continue_campaign(runs) {
             let initial_seq = corpus_manager.new_sequence(&invariant_test)?;
 
@@ -407,9 +411,9 @@ impl<'a> InvariantExecutor<'a> {
 
                 // Collect line coverage from last fuzzed call.
                 invariant_test.merge_coverage(call_result.line_coverage.clone());
-                // If coverage guided fuzzing is enabled then merge edge count with current history
+                // If running with edge coverage then merge edge count with the current history
                 // map and set new coverage in current run.
-                if self.config.corpus_dir.is_some() {
+                if edge_coverage_enabled {
                     let (new_coverage, is_edge) =
                         call_result.merge_edge_coverage(&mut self.history_map);
                     if new_coverage {
@@ -514,15 +518,14 @@ impl<'a> InvariantExecutor<'a> {
 
             // End current invariant test run.
             invariant_test.end_run(current_run, self.config.gas_report_samples as usize);
-
             if let Some(progress) = progress {
                 // If running with progress then increment completed runs.
                 progress.inc(1);
                 // Display metrics in progress bar.
-                if self.config.corpus_dir.is_some() {
+                if edge_coverage_enabled {
                     progress.set_message(format!("{}", &corpus_manager.metrics));
                 }
-            } else if self.config.corpus_dir.is_some()
+            } else if edge_coverage_enabled
                 && last_metrics_report.elapsed() > DURATION_BETWEEN_METRICS_REPORT
             {
                 // Display metrics inline if corpus dir set.

crates/evm/evm/src/inspectors/stack.rs

@@ -211,7 +211,6 @@ impl InspectorStackBuilder {
             stack.set_chisel(chisel_state);
         }
         stack.collect_line_coverage(line_coverage.unwrap_or(false));
-        stack.collect_edge_coverage(true);
         stack.collect_logs(logs.unwrap_or(true));
         stack.print(print.unwrap_or(false));
         stack.tracing(trace_mode);

crates/forge/src/runner.rs

@@ -705,8 +705,15 @@ impl<'a> FunctionRunner<'a> {
         let runner = self.invariant_runner();
         let invariant_config = &self.config.invariant;
 
+        let mut executor = self.clone_executor();
+        // Enable edge coverage if running with coverage guided fuzzing or with edge coverage
+        // metrics (useful for benchmarking the fuzzer).
+        executor.inspector_mut().collect_edge_coverage(
+            invariant_config.corpus_dir.is_some() || invariant_config.show_edge_coverage,
+        );
+
         let mut evm = InvariantExecutor::new(
-            self.clone_executor(),
+            executor,
             runner,
             invariant_config.clone(),
             identified_contracts,

crates/forge/tests/cli/config.rs

@@ -1121,6 +1121,7 @@ corpus_min_size = 0
 failure_persist_dir = "cache/invariant"
 show_metrics = true
 show_solidity = false
+show_edge_coverage = false
 
 [labels]
 
@@ -1234,7 +1235,8 @@ exclude = []
     "failure_persist_dir": "cache/invariant",
     "show_metrics": true,
     "timeout": null,
-    "show_solidity": false
+    "show_solidity": false,
+    "show_edge_coverage": false
   },
   "ffi": false,
   "allow_internal_expect_revert": false,

crates/forge/tests/it/test_helpers.rs

@@ -160,6 +160,7 @@ impl ForgeTestProfile {
             show_metrics: true,
             timeout: None,
             show_solidity: false,
+            show_edge_coverage: false,
         };
 
         config.sanitized()