Add another XSS test

xss/testdata/src/e/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+)
+
+func echo(w io.Writer, r any) error {
+	ior, ok := r.(io.Reader)
+	if !ok {
+		return fmt.Errorf("failed to cast to io.Reader")
+	}
+
+	b, err := io.ReadAll(ior)
+	if err != nil {
+		return fmt.Errorf("failed to read all bytes from io.Reader: %w", err)
+	}
+
+	w.Write(b)
+
+	return nil
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	err := echo(w, r) // want "potential XSS"
+	if err != nil {
+		panic(err)
+	}
+}
+
+func main() {
+	http.HandleFunc("/mirror-safe", handler)
+
+	http.ListenAndServe(":8080", nil)
+}

xss/xss_test.go

@@ -23,3 +23,8 @@ func TestC(t *testing.T) {
 func TestD(t *testing.T) {
 	analysistest.Run(t, testdata, Analyzer, "d")
 }
+
+func TestE(t *testing.T) {
+	analysistest.Run(t, testdata, Analyzer, "e")
+}
+