add test filter_timeout with rtype TXT in cache_by_recor_type

src/dns_cache/cache_by_record_type.rs

@@ -696,6 +696,48 @@ mod cache_data_test{
 
     }
 
+    #[test]
+    fn filter_timeout_cache_data_rtype_txt() {
+        use std::{thread, time};
+        let mut cache_record_type = CacheByRecordType::new();
+        let txt_rdata = Rdata::TXT(TxtRdata::new(vec![String::from("test")]));
+
+        let mut resource_record_valid = ResourceRecord::new(txt_rdata.clone());
+        resource_record_valid.set_ttl(1000);
+        let rr_cache_valid = RRStoredData::new(resource_record_valid.clone());
+
+        let mut resource_record_invalid = ResourceRecord::new(txt_rdata);
+        resource_record_invalid.set_ttl(4);
+        let rr_cache_invalid = RRStoredData::new(resource_record_invalid);
+
+        let mut domain_name = DomainName::new();
+        domain_name.set_name(String::from("uchile.cl"));
+
+        cache_record_type.add_to_cache_data(Rtype::TXT, domain_name.clone(), rr_cache_valid);
+        cache_record_type.add_to_cache_data(Rtype::TXT, domain_name.clone(), rr_cache_invalid);
+
+        //check if the domain with A type has 2 RRStoredData
+        if let Some(rr_cache_vec) = cache_record_type.get_from_cache_data(domain_name.clone(), Rtype::TXT){
+            assert_eq!(rr_cache_vec.len(), 2);
+        }
+
+        println!("Before timeout: {:?}", Utc::now());
+        thread::sleep(time::Duration::from_secs(5));
+        println!("After timeout: {:?}", Utc::now());
+        cache_record_type.filter_timeout_cache_data();
+
+        //check if the len is 1 instead of 2 (one RRStoredData was eliminated)
+        if let Some(rr_cache_vec) = cache_record_type.get_from_cache_data(domain_name.clone(), Rtype::TXT){
+            assert_eq!(rr_cache_vec.len(), 1);
+            //chek if the resource record who survives is the right one
+            if let Some(rrstore_data_valid) = rr_cache_vec.get(0){
+                let resource_record_after_filter = rrstore_data_valid.get_resource_record();
+                assert_eq!(resource_record_after_filter, resource_record_valid);
+            }
+        }
+
+    }
+
     #[test]
     fn filter_timout_cache_data_2_differents_rtypes(){
         use std::{thread, time};