diff --git a/test/Makefile b/test/Makefile
index c09983b..400191d 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -3,9 +3,9 @@ HTSLIB   = /usr/local/lib
 # detect OS architecture and add flags
 CXX      = g++
 CXXFLAGS = -std=c++11 -Wall -fsanitize=address
-# CXXFLAGS = -std=c++11 -Wall
+# CXXFLAGS = -std=c++11 -Wall -g
 LDFLAGS  =  -L$(HTSLIB) -Wl,-rpath,$(HTSLIB)
-LIBS     = -lhts -lz -lm -lbz2 -llzma -lcurl -lpthread
+LIBS     = -lhts
 INC      = -I. -I.. -I${HTSINC}
 
 OBJS = test-main.o bcf-variant.o bcf-reader.o bcf-writer.o example.o
diff --git a/test/bcf-reader.cpp b/test/bcf-reader.cpp
index e43c581..73c3fc3 100644
--- a/test/bcf-reader.cpp
+++ b/test/bcf-reader.cpp
@@ -64,26 +64,6 @@ TEST_CASE("parse vcf with missing genotypes diploid - vector<int>", "[bcf-reader
     REQUIRE(n == 1);
 }
 
-TEST_CASE("parse vcf with multialleles - vector<int>", "[bcf-reader]")
-{
-    string vcffile{"test-multialleles.vcf.gz"};
-    BcfWriter bw(vcffile, "VCF4.2");
-    bw.header.addContig("chr20"); 
-    bw.header.addINFO("AF", "A", "Float", "Estimated allele frequency in the range (0,1)");
-    bw.header.addFORMAT("GT", "1", "String", "Genotype");
-    for(auto & s : {"id01", "id02", "id03"}) bw.header.addSample(s); // add 3 samples
-    bw.writeLine("chr20\t2006060\trs146931526\tG\tA,T\t100\tPASS\tAF=0.02\tGT\t1|2\t1|1\t0|2");
-    bw.close();
-    BcfReader br("test-multialleles.vcf.gz");
-    BcfRecord var(br.header);
-    vector<int> gt;
-    while(br.getNextVariant(var))
-    {
-        var.getGenotypes(gt);
-        for(auto g : gt) cout << g << endl;
-    }
-}
-
 TEST_CASE("parse PL in vcf - vector<int>", "[bcf-reader]")
 {
     string vcffile{"test-GL.vcf.gz"};
@@ -98,11 +78,9 @@ TEST_CASE("parse PL in vcf - vector<int>", "[bcf-reader]")
     BcfReader br(vcffile);
     BcfRecord var(br.header);
     vector<int> pl;
-    while(br.getNextVariant(var))
-    {
-        var.getFORMAT("PL",pl);
-        for(auto g : pl) cout << g << endl;
-    }
+    REQUIRE(br.getNextVariant(var)==true);
+    var.getFORMAT("PL",pl);
+    for(auto g : pl) cout << g << endl;
 }
 
 TEST_CASE("parse GL in vcf - vector<float>", "[bcf-reader]")
@@ -119,9 +97,28 @@ TEST_CASE("parse GL in vcf - vector<float>", "[bcf-reader]")
     BcfReader br(vcffile);
     BcfRecord var(br.header);
     vector<float> gl;
-    while(br.getNextVariant(var))
-    {
-        var.getFORMAT("GL",gl);
-        for(auto g : gl) cout << g << endl;
-    }
+    REQUIRE(br.getNextVariant(var)==true);
+    var.getFORMAT("GL",gl);
+    for(auto g : gl) cout << g << endl;
+}
+
+TEST_CASE("parse vcf with multialleles - vector<int>", "[bcf-reader]")
+{
+    string vcffile{"test-multialleles.vcf.gz"};
+    BcfWriter bw(vcffile, "VCF4.2");
+    bw.header.addContig("chr20"); 
+    bw.header.addINFO("AF", "A", "Float", "Estimated allele frequency in the range (0,1)");
+    bw.header.addFORMAT("GT", "1", "String", "Genotype");
+    for(auto & s : {"id01", "id02", "id03"}) bw.header.addSample(s); // add 3 samples
+    string l1 = "chr20\t2006060\trs146931526\tG\tA,T\t100\tPASS\tAF=0.02\tGT\t1|2\t1|1\t0|2";
+    bw.writeLine(l1);
+    bw.close();
+    BcfReader br("test-multialleles.vcf.gz");
+    BcfRecord var(br.header);
+    vector<int> gt;
+    REQUIRE(br.getNextVariant(var)==true);
+    auto l2 = var.asString();
+    REQUIRE(l2 == l1 + "\n");
+    var.getGenotypes(gt);
+    for(auto g : gt) cout << g << endl;
 }
diff --git a/test/bcf-variant.cpp b/test/bcf-variant.cpp
index b25b1bc..165fc44 100644
--- a/test/bcf-variant.cpp
+++ b/test/bcf-variant.cpp
@@ -10,13 +10,12 @@ TEST_CASE("set genotypes without missing ", "[bcf-variant]")
     BcfRecord v(br.header);
     vector<int> gt;
     vector<int> gi{1, 1};
-    if(br.getNextVariant(v))
+    while(br.getNextVariant(v))
     {
         v.getGenotypes(gt);
-        for(auto g : gt) cerr << g << endl;
         v.setGenotypes(gi);
         v.getGenotypes(gt);
-        for(auto g : gt) cerr << g << endl;
+        for(size_t i = 0; i < gt.size(); i++) REQUIRE(gt[i] == gi[i]);
     }
 }
 
@@ -25,18 +24,17 @@ TEST_CASE("set genotypes with missing ", "[bcf-variant]")
     BcfReader br("test-vcf-read.vcf.gz");
     BcfRecord v(br.header);
     vector<int> gt;
-    vector<int> gi{1, -9};
-    vector<int> g2{-2147483648, -9};
-    br.getNextVariant(v);
-    if(br.getNextVariant(v))
+    vector<int> gi{1, -9}; // -9 as missing
+    vector<int> g2{-2147483648, -9}; // also, bcf_int32_missing (R_NA) as missing
+    // br.getNextVariant(v);
+    while(br.getNextVariant(v))
     {
         v.getGenotypes(gt);
-        for(auto g : gt) cerr << g << endl;
         v.setGenotypes(gi);
         v.getGenotypes(gt);
-        for(auto g : gt) cerr << g << endl;
+        for(size_t i = 0; i < gt.size(); i++) REQUIRE(gt[i] == gi[i]);
         v.setGenotypes(g2);
         v.getGenotypes(gt);
-        for(auto g : gt) cerr << g << endl;
+        for(size_t i = 0; i < gt.size(); i++) REQUIRE(gt[i] == -9);
     }
 }
diff --git a/vcfpp.h b/vcfpp.h
index ff03ca6..2c721a5 100644
--- a/vcfpp.h
+++ b/vcfpp.h
@@ -157,7 +157,6 @@ struct variant_close
     }
 };
 
-
 // deleter for bcf header
 struct bcf_hdr_close
 {
@@ -166,7 +165,7 @@ struct bcf_hdr_close
         if(x) bcf_hdr_destroy(x);
     }
 };
-    
+
 /**
  * @class BcfHeader
  * @brief Object represents header of the VCF, offering methods to access and modify the tags
@@ -394,9 +393,9 @@ class BcfRecord
     friend class BcfWriter;
 
   private:
-    BcfHeader* header;
+    BcfHeader * header;
     std::shared_ptr<bcf1_t> line = std::shared_ptr<bcf1_t>(bcf_init(), variant_close()); // variant
-    bcf_hdr_t * hdr_d; // a dup header by bcf_hdr_dup(header->hdr)
+    bcf_hdr_t * hdr_d = NULL; // a dup header by bcf_hdr_dup(header->hdr)
     bcf_fmt_t * fmt = NULL;
     bcf_info_t * info = NULL;
     int32_t * gts = NULL;
@@ -420,7 +419,11 @@ class BcfRecord
         init(h);
     }
 
-    ~BcfRecord() {}
+    ~BcfRecord()
+    {
+        if(gts) free(gts);
+        if(hdr_d) bcf_hdr_destroy(hdr_d);
+    }
 
     /// initilize a BcfRecord object by pointing to another BcfHeader object
     void init(BcfHeader & h)
@@ -601,6 +604,7 @@ class BcfRecord
         }
         else
         {
+            free(dst);
             throw std::runtime_error("failed to parse the " + tag + " format of this variant.\n");
         }
     }
@@ -634,6 +638,7 @@ class BcfRecord
         }
         else
         {
+            free(dst);
             throw std::runtime_error("couldn't parse the " + tag + " format of this variant.\n");
         }
     }
@@ -661,10 +666,15 @@ class BcfRecord
             ret = bcf_get_info_float(header->hdr, line.get(), tag.c_str(), &dst, &ndst);
         }
         if(ret >= 0)
+        {
             v = std::vector<S>(dst, dst + ret); // user have to check if there is missing in the return v;
+            free(dst);
+        }
         else
+        {
+            free(dst);
             throw std::runtime_error("couldn't parse the " + tag + " format of this variant.\n");
-        free(dst);
+        }
         return true;
     }
 
@@ -798,22 +808,26 @@ class BcfRecord
         // bcf_gt_type
         int i, j, k;
         nploidy = v.size() / nsamples;
-        gts = (int32_t *)malloc(v.size() * sizeof(int32_t));
+        int32_t * gt = (int32_t *)malloc(v.size() * sizeof(int32_t));
         for(i = 0; i < nsamples; i++)
         {
             for(j = 0; j < nploidy; j++)
             {
                 k = i * nploidy + j;
                 if(v[k] == -9 || v[k] == bcf_int32_missing)
-                    gts[k] = bcf_gt_missing;
+                    gt[k] = bcf_gt_missing;
                 else if(gtPhase[i])
-                    gts[k] = bcf_gt_phased(v[k]);
+                    gt[k] = bcf_gt_phased(v[k]);
                 else
-                    gts[k] = bcf_gt_unphased(v[k]);
+                    gt[k] = bcf_gt_unphased(v[k]);
             }
         }
-        if(bcf_update_genotypes(header->hdr, line.get(), gts, v.size()) < 0)
+        if(bcf_update_genotypes(header->hdr, line.get(), gt, v.size()) < 0)
+        {
+            free(gt);
             throw std::runtime_error("couldn't set genotypes correctly.\n");
+        }
+        free(gt);
         return true;
     }
 
@@ -1276,7 +1290,7 @@ class BcfReader
     std::shared_ptr<htsFile> fp; // hts file
     hts_idx_t * hidx = NULL; // hts index file
     tbx_t * tidx = NULL; // .tbi .csi index file for vcf files
-    hts_itr_t * itr = NULL; // hts records iterator
+    hts_itr_t * itr = NULL; // tabix iterator
     kstring_t s = {0, 0, NULL}; // kstring
     std::string fname;
     bool isBcf; // if the input file is bcf or vcf;
@@ -1330,10 +1344,19 @@ class BcfReader
         if(!samples.empty()) setSamples(samples);
     }
 
-    /// return a BcfHeader object
-    const BcfHeader & getHeader() const
+    ~BcfReader()
     {
-        return header;
+        close();
+    }
+
+    /// close the BcfReader object.
+    void close()
+    {
+        if(fp) fp.reset();
+        if(itr) hts_itr_destroy(itr);
+        if(hidx) hts_idx_destroy(hidx);
+        if(tidx) tbx_destroy(tidx);
+        if(s.s) free(s.s);
     }
 
     /// open a VCF/BCF/STDIN file for streaming in
@@ -1355,22 +1378,18 @@ class BcfReader
             return false;
     }
 
-    /// close the BcfReader object.
-    void close()
-    {
-        free(s.s);
-        if(fp) fp.reset();
-        if(itr) hts_itr_destroy(itr);
-    }
-
-    ~BcfReader() {}
-
     /** @brief set the number of threads to use */
     inline int setThreads(int n)
     {
         return hts_set_threads(fp.get(), n);
     }
 
+    /// return a BcfHeader object
+    const BcfHeader & getHeader() const
+    {
+        return header;
+    }
+
     /** @brief get the number of records of given region */
     uint64_t getVariantsCount(BcfRecord & r, const std::string & region)
     {