fix(coverage): write coverage file even when tests fail

crates/forge/src/cmd/coverage.rs

@@ -250,7 +250,6 @@ impl CoverageArgs {
         let filter = self.test.filter(&config)?;
         let outcome =
             self.test.run_tests(project_root, config, evm_opts, output, &filter, true).await?;
-        outcome.ensure_ok(false)?;
 
         let known_contracts = outcome.runner.as_ref().unwrap().known_contracts.clone();
 
@@ -300,6 +299,10 @@ impl CoverageArgs {
         // Output final reports.
         self.report(&report)?;
 
+        // Check for test failures after generating coverage report.
+        // This ensures coverage data is written even when tests fail.
+        outcome.ensure_ok(false)?;
+
         Ok(())
     }
 

crates/forge/tests/cli/coverage.rs

@@ -2203,3 +2203,66 @@ contract CounterTest is DSTest {
 ...
 "#]]);
 });
+
+// Test that coverage files are written even when tests fail.
+forgetest!(coverage_with_failing_tests, |prj, cmd| {
+    prj.insert_ds_test();
+    prj.add_source(
+        "Counter.sol",
+        r#"
+contract Counter {
+    uint256 public number;
+
+    function setNumber(uint256 newNumber) public {
+        number = newNumber;
+    }
+
+    function increment() public {
+        number++;
+    }
+}
+    "#,
+    );
+
+    prj.add_source(
+        "CounterTest.sol",
+        r#"
+import "./test.sol";
+import {Counter} from "./Counter.sol";
+
+contract CounterTest is DSTest {
+    Counter public counter;
+
+    function setUp() public {
+        counter = new Counter();
+        counter.setNumber(0);
+    }
+
+    function test_Increment() public {
+        counter.increment();
+        assertEq(counter.number(), 1);
+    }
+
+    function test_FailingTest() public {
+        counter.increment();
+        // This assertion will fail
+        assertEq(counter.number(), 999);
+    }
+}
+    "#,
+    );
+
+    // Run coverage - this should exit with error code 1 due to failing test,
+    // but the lcov file should still be written.
+    cmd.arg("coverage").args(["--report=lcov"]).assert_failure();
+
+    // Verify that the lcov.info file was created despite test failure
+    let lcov = prj.root().join("lcov.info");
+    assert!(lcov.exists(), "lcov.info should be created even when tests fail");
+
+    // Verify the coverage data is valid and includes the counter contract
+    let lcov_content = std::fs::read_to_string(&lcov).unwrap();
+    assert!(lcov_content.contains("SF:src/Counter.sol"), "Coverage should include Counter.sol");
+    assert!(lcov_content.contains("FN:"), "Coverage should include function data");
+    assert!(lcov_content.contains("DA:"), "Coverage should include line hit data");
+});