fix: Windows NO_COVERAGE issue

internal/coverage/coverage.go

@@ -203,5 +203,5 @@ func (c *Coverage) removeModuleFromPath(p *cover.Profile) string {
 	path := strings.ReplaceAll(p.FileName, c.mod.Name+"/", "")
 	path, _ = filepath.Rel(c.mod.CallingDir, path)
 
-	return path
+	return filepath.ToSlash(path) // normalize to slashes
 }

internal/coverage/profile_test.go

@@ -215,3 +215,21 @@
 		})
 	}
 }
+
+func TestIsCovered_PathsWithSlashes(t *testing.T) {
+    profile := coverage.Profile{
+        "internal/coverage/file.go": []coverage.Block{
+            {StartLine: 10, StartCol: 1, EndLine: 20, EndCol: 1},
+        },
+    }
+
+    pos := token.Position{
+        Filename: "internal/coverage/file.go",
+        Line:     15,
+        Column:   5,
+    }
+
+    if !profile.IsCovered(pos) {
+        t.Error("expected position to be covered")
+    }
+}

internal/engine/stubs_test.go

@@ -18,6 +18,7 @@ package engine_test
 
 import (
 	"errors"
+	"fmt"
 	"go/token"
 	"io"
 	"os"
@@ -56,8 +57,15 @@ func viperReset() {
 
 func loadFixture(fixture, fromPackage string) (fstest.MapFS, gomodule.GoModule, func()) {
 	//nolint:gosec // test code reading test fixtures
-	f, _ := os.Open(fixture)
-	src, _ := io.ReadAll(f)
+	f, err := os.Open(fixture)
+	if err != nil {
+		panic(fmt.Sprintf("failed to open test fixture %s: %v", fixture, err))
+	}
+	src, err := io.ReadAll(f)
+	if err != nil {
+		_ = f.Close()
+		panic(fmt.Sprintf("failed to read test fixture %s: %v", fixture, err))
+	}
 	filename := filenameFromFixture(fixture)
 	mapFS := fstest.MapFS{
 		filename: {Data: src},