diff --git a/tests/testthat/test-popgen.R b/tests/testthat/test-popgen.R
index 51d7117..5209ba1 100644
--- a/tests/testthat/test-popgen.R
+++ b/tests/testthat/test-popgen.R
@@ -2,7 +2,7 @@ vcffile <- system.file("extdata", "raw.gt.vcf.gz", package="vcfppR")
 
 test_that("both vcftable and vcfreader work for calculating heterzygosity", {
   vcf <- vcftable(vcffile, vartype = "snps")
-  res1 <- colSums(vcf[["gt"]]==1, na.rm = TRUE)
+  res1 <- as.integer(colSums(vcf[["gt"]]==1, na.rm = TRUE))
   br <- vcfreader$new(vcffile)
   res2 <- rep(0L, br$nsamples())
   while(br$variant()) {
@@ -14,3 +14,11 @@ test_that("both vcftable and vcfreader work for calculating heterzygosity", {
   }
   expect_identical(as.integer(res1), res2)
 })
+
+test_that("heterzygosity only counts snps", {
+  vcf <- vcftable(vcffile, vartype = "snps", pass = TRUE)
+  res1 <- as.integer(colSums(vcf[["gt"]]==1, na.rm = TRUE))
+  vcf <- vcfpopgen(vcffile, pass = TRUE, fun = "heterozygosity")
+  res2 <- vcf$hets
+  expect_identical(res1, res2)
+})
diff --git a/tests/testthat/test-vcf-reader.R b/tests/testthat/test-vcf-reader.R
index fd1b4c1..20eb365 100644
--- a/tests/testthat/test-vcf-reader.R
+++ b/tests/testthat/test-vcf-reader.R
@@ -1,6 +1,117 @@
 library(testthat)
 
 vcffile <- system.file("extdata", "raw.gt.vcf.gz", package="vcfppR")
+svfile <- system.file("extdata", "sv.vcf.gz", package="vcfppR")
+
+test_that("vcfreader: constructor with vcfffile only", {
+  br <- vcfreader$new(vcffile)
+  br$variant()
+  expect_identical(br$chr(), "chr21")
+  expect_identical(br$pos(), 5030082L)
+  expect_identical(br$id(), "chr21:5030082:G:A")
+  expect_identical(br$ref(), "G")
+  expect_identical(br$alt(), "A")
+})
+
+test_that("vcfreader: constructor with vcfffile and region", {
+  br <- vcfreader$new(vcffile, "chr21:5030082-")
+  br$variant()
+  expect_identical(br$chr(), "chr21")
+  expect_identical(br$pos(), 5030082L)
+  expect_identical(br$id(), "chr21:5030082:G:A")
+  expect_identical(br$ref(), "G")
+  expect_identical(br$alt(), "A")
+})
+
+test_that("vcfreader: constructor with vcfffile, region and samples", {
+  br <- vcfreader$new(vcffile, "chr21:5030082-", "HG00097,HG00099")
+  br$variant()
+  expect_identical(br$genotypes(F), rep(0L, 4))
+  expect_identical(br$chr(), "chr21")
+  expect_identical(br$pos(), 5030082L)
+  expect_identical(br$id(), "chr21:5030082:G:A")
+  expect_identical(br$ref(), "G")
+  expect_identical(br$alt(), "A")
+})
+
+test_that("vcfreader: get FORMAT item with Float type", {
+  br <- vcfreader$new(vcffile, "chr21:5030347-", "HG00097,HG00099")
+  br$variant()
+  expect_identical(br$pos(), 5030347L)
+  expect_identical(all(is.na(br$formatFloat("AB"))), TRUE)
+})
+
+test_that("vcfreader: get FORMAT item with Integer type", {
+  br <- vcfreader$new(vcffile, "chr21:5030347-", "HG00097,HG00099")
+  br$variant()
+  expect_identical(br$pos(), 5030347L)
+  expect_identical(br$formatInt("AD"), c(4L, 0L, 16L, 0L))
+})
+
+test_that("vcfreader: get FORMAT item with String type", {
+  br <- vcfreader$new(svfile, "chr21:5114000-", "HG00096,HG00097")
+  expect_true(br$variant())
+  expect_identical(br$pos(), 5114000L)
+  expect_identical(br$formatStr("EV"), c("RD","RD"))
+})
+
+test_that("vcfreader: get FORMAT item for the unexpected and error", {
+  br <- vcfreader$new(vcffile, "chr21:5030347-", "HG00097,HG00099")
+  br$variant()
+  expect_identical(br$pos(), 5030347L)
+  expect_error(br$formatInt("AA")) ## AA not exists
+  expect_identical(br$formatInt("AD"), c(4L, 0L, 16L, 0L))
+  ## use formatFloat will return unexpected values if AD in FORMAT if Integer
+  expect_error(expect_identical(br$formatFloat("AD"), c(4L, 0L, 16L, 0L))) ## AA exists but of Integer type
+})
+
+test_that("vcfreader: get variants type", {
+  br <- vcfreader$new(vcffile)
+  i <- 0
+  s <- 0
+  m <- 0
+  ms <- 0
+  while(br$variant()) {
+    if(br$isIndel()) i <- i + 1
+    if(br$isSV()) s <- s + 1
+    if(br$isMultiAllelics()) m <- m + 1
+    if(br$isMultiAllelicSNP()) ms <- ms + 1
+  }
+  expect_identical(i, 6)
+  expect_identical(s, 0)
+  expect_identical(m, 4)
+  expect_identical(ms, 3)
+})
+
+test_that("vcfreader: test variants type", {
+  br <- vcfreader$new(vcffile)
+  i1 <- 0
+  i2 <- 0
+  i3 <- 0
+  i4 <- 0
+  i5 <- 0
+  i6 <- 0
+  i7 <- 0
+  i8 <- 0
+  while(br$variant()) {
+    if(br$hasSNP()) i1 <- i1 + 1
+    if(br$hasINDEL()) i2 <- i2 + 1
+    if(br$hasINS()) i3 <- i3 + 1
+    if(br$hasDEL()) i4 <- i4 + 1
+    if(br$hasMNP()) i5 <- i5 + 1
+    if(br$hasBND()) i6 <- i6 + 1
+    if(br$hasOTHER()) i7 <- i7 + 1
+    if(br$hasOVERLAP()) i8 <- i8 + 1
+  }
+  expect_identical(i1, 66)
+  expect_identical(i2, 6)
+  expect_identical(i3, 3)
+  expect_identical(i4, 4)
+  expect_identical(i5, 0)
+  expect_identical(i6, 0)
+  expect_identical(i7, 0)
+  expect_identical(i8, 1)
+})
 
 test_that("vcfreader: reading variant only", {
   br <- vcfreader$new(vcffile)
@@ -13,6 +124,9 @@ test_that("vcfreader: reading variant only", {
   expect_equal(br$qual(), 70.06, tolerance = 1e-6)
   expect_identical(br$filter(), "VQSRTrancheSNP99.80to100.00")
   expect_identical(br$info(), "AC=2;AF=0.000616523;AN=3244;DP=2498;FS=0;MLEAC=1;MLEAF=0.0003083;MQ=17.07;MQ0=0;QD=17.52;SOR=3.258;VQSLOD=-32.6;culprit=MQ;AN_EUR=658;AN_EAS=548;AN_AMR=520;AN_SAS=624;AN_AFR=894;AF_EUR=0;AF_EAS=0;AF_AMR=0.00384615;AF_SAS=0;AF_AFR=0;AC_EUR=0;AC_EAS=0;AC_AMR=2;AC_SAS=0;AC_AFR=0;AC_Het_EUR=0;AC_Het_EAS=0;AC_Het_AMR=0;AC_Het_SAS=0;AC_Het_AFR=0;AC_Het=0;AC_Hom_EUR=0;AC_Hom_EAS=0;AC_Hom_AMR=2;AC_Hom_SAS=0;AC_Hom_AFR=0;AC_Hom=2;HWE_EUR=1;ExcHet_EUR=1;HWE_EAS=1;ExcHet_EAS=1;HWE_AMR=0.00192678;ExcHet_AMR=1;HWE_SAS=1;ExcHet_SAS=1;HWE_AFR=1;ExcHet_AFR=1;HWE=0.000308356;ExcHet=1;ME=0;AN_EUR_unrel=508;AN_EAS_unrel=448;AN_AMR_unrel=330;AN_SAS_unrel=484;AN_AFR_unrel=666;AF_EUR_unrel=0;AF_EAS_unrel=0;AF_AMR_unrel=0;AF_SAS_unrel=0;AF_AFR_unrel=0;AC_EUR_unrel=0;AC_EAS_unrel=0;AC_AMR_unrel=0;AC_SAS_unrel=0;AC_AFR_unrel=0;AC_Het_EUR_unrel=0;AC_Het_EAS_unrel=0;AC_Het_AMR_unrel=0;AC_Het_SAS_unrel=0;AC_Het_AFR_unrel=0;AC_Hom_EUR_unrel=0;AC_Hom_EAS_unrel=0;AC_Hom_AMR_unrel=0;AC_Hom_SAS_unrel=0;AC_Hom_AFR_unrel=0")
+  br$rmInfoTag("AC")
+  print(br$info())
+  print(br$infoInt("AC")) ## TODO: AC value still exists
   af <- br$infoFloat("AF")
   ## expect_equal(0.00061652297, 0.00061652300, tolerance = 1e-6)
   expect_equal(af, 0.000616523, tolerance = 1e-6)
diff --git a/tests/testthat/test-vcf-table.R b/tests/testthat/test-vcf-table.R
index 6414e17..87e5a1b 100644
--- a/tests/testthat/test-vcf-table.R
+++ b/tests/testthat/test-vcf-table.R
@@ -26,6 +26,18 @@ test_that("extract GT for variant with ID=chr21:5030516:G:A", {
   expect_equal(res$alt, "A")
 })
 
+test_that("extract GT for all multisnps", {
+  res <- vcftable(vcffile, vartype = "multisnps")
+  expect_identical(res$ref, c("C", "C", "G"))
+  expect_identical(res$alt, c("G,T", "T,G", "T,*"))
+})
+
+test_that("extract GT for all multiallelics", {
+  res <- vcftable(vcffile, vartype = "multiallelics")
+  expect_identical(res$ref, c("C", "C", "CTTTTTT","G"))
+  expect_identical(res$alt, c("G,T", "T,G", "CTTTTT,CTTTTTTT,C", "T,*"))
+})
+
 test_that("extract AD (Integer, number=.) for variant with ID=chr21:5030247:G:A", {
   res <- vcftable(vcffile, id = c("chr21:5030347:G:A"), pass = TRUE, format = "AD")
   expect_equal(nrow(res$AD), 1)