diff --git a/R/apex.R b/R/apex.R
index 3fef68c..78a5115 100644
--- a/R/apex.R
+++ b/R/apex.R
@@ -33,7 +33,7 @@ apex <- function(data, mapping, type = "column", ..., auto_update = TRUE, width
       series = make_series(mapdata, mapping, type)
     )
   }
-  opts <- modifyList(opts, choose_config(type, is_datetime(mapdata)))
+  opts <- modifyList(opts, choose_config(type, is_x_datetime(mapdata)))
   apexchart(
     ax_opts = opts, width = width, height = height,
     elementId = elementId, auto_update = auto_update
@@ -66,7 +66,7 @@ make_series <- function(mapdata, mapping, type) {
 }
 
 
-is_datetime <- function(mapdata) {
+is_x_datetime <- function(mapdata) {
   inherits(mapdata$x, what = c("Date", "POSIXt"))
 }
 list1 <- function(x) {
diff --git a/R/utils.R b/R/utils.R
index f0713d4..43cbdce 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -29,10 +29,6 @@ formatNoSci <- function(x) {
 #' @noRd
 .ax_opt <- function(ax, name, ...) {
   
-  if(!any(class(ax) %in% c("apexcharter", "apexcharter_Proxy"))){
-    stop("ax must be a apexcharter or a apexcharterProxy object")
-  }
-  
   if (is.null(ax$x$ax_opts[[name]])) {
     ax$x$ax_opts[[name]] <- list(...)
   } else {
diff --git a/inst/examples-proxy/bar-auto/server.R b/inst/examples-proxy/bar-auto/server.R
index 85eb013..a3966f6 100644
--- a/inst/examples-proxy/bar-auto/server.R
+++ b/inst/examples-proxy/bar-auto/server.R
@@ -26,7 +26,7 @@ function(input, output, session) {
   
   
   output$chart <- renderApexchart({
-    apex(data = data_r(), type = "bar", mapping = aes(x = manufacturer, y = n, fill = year), auto_update = F)
+    apex(data = data_r(), type = "bar", mapping = aes(x = manufacturer, y = n, fill = year))
   })
   
 }
diff --git a/tests/testthat/test-apex-utils.R b/tests/testthat/test-apex-utils.R
new file mode 100644
index 0000000..14ec001
--- /dev/null
+++ b/tests/testthat/test-apex-utils.R
@@ -0,0 +1,45 @@
+context("test-apex-utils")
+
+test_that("is_x_datetime works", {
+  expect_true(is_x_datetime(list(x = Sys.Date())))
+  expect_true(is_x_datetime(list(x = Sys.time())))
+  expect_false(is_x_datetime(list(x = letters)))
+})
+
+
+test_that("list1 works", {
+  expect_is(list1(1), "list")
+  expect_is(list1(1:2), "integer")
+  expect_length(list1(1:2), 2)
+})
+
+
+test_that("correct_type works", {
+  expect_identical(correct_type("bar"), "bar")
+  expect_identical(correct_type("column"), "bar")
+  expect_identical(correct_type("line"), "line")
+  expect_identical(correct_type("spline"), "line")
+  expect_identical(correct_type("pie"), "pie")
+})
+
+
+test_that("make_series works", {
+  serie <- make_series(iris, aes(x = Sepal.Length, y = Sepal.Width))
+  expect_is(serie, "list")
+  expect_length(serie, 1)
+  expect_length(serie[[1]], 2)
+  expect_named(serie[[1]], c("name", "data"))
+})
+
+test_that("make_series works with group", {
+  mapping <- aes(x = Sepal.Length, y = Sepal.Width, fill = Species)
+  mapdata <- lapply(mapping, rlang::eval_tidy, data = iris)
+  serie <- make_series(mapdata, mapping)
+  expect_is(serie, "list")
+  expect_length(serie, 3)
+  expect_length(serie[[1]], 2)
+  expect_named(serie[[1]], c("name", "data"))
+})
+
+
+
diff --git a/tests/testthat/test-ax_opt.R b/tests/testthat/test-ax_opt.R
index a4e5593..5ef1e39 100644
--- a/tests/testthat/test-ax_opt.R
+++ b/tests/testthat/test-ax_opt.R
@@ -40,9 +40,11 @@ test_that("ax_opt2 works", {
   ), class = c("list", "apexcharter"))
   
   new_opts <- .ax_opt2(opts, "series", list(data = 1:3))
+  new_opts <- .ax_opt2(new_opts, "chart", list(type = "line"))
   
   expect_length(new_opts$x$ax_opts, 2)
   expect_named(new_opts$x$ax_opts, c("chart", "series"))
   expect_identical(new_opts$x$ax_opts$series$data, 1:3)
+  expect_identical(new_opts$x$ax_opts$chart$type, "line")
 })
 
diff --git a/tests/testthat/test-example-readme.R b/tests/testthat/test-example-readme.R
new file mode 100644
index 0000000..96755bd
--- /dev/null
+++ b/tests/testthat/test-example-readme.R
@@ -0,0 +1,40 @@
+context("test-example-readme")
+
+test_that("readme exemple works", {
+  
+  n_manufac <- structure(list(
+    manufacturer = c("audi", "chevrolet", "dodge", 
+                     "ford", "honda", "hyundai", "jeep", "land rover", "lincoln", 
+                     "mercury", "nissan", "pontiac", "subaru", "toyota", "volkswagen"
+    ), 
+    n = c(18L, 19L, 37L, 25L, 9L, 14L, 8L, 4L, 3L, 4L, 13L, 5L, 14L, 34L, 27L)
+  ), row.names = c(NA, -15L), class = c("tbl_df", "tbl", "data.frame"))
+  
+  ax <- apexchart() %>% 
+    ax_chart(type = "bar") %>% 
+    ax_plotOptions(bar = barOpts(
+      horizontal = FALSE,
+      endingShape = "flat",
+      columnWidth = "70%",
+      dataLabels = list(
+        position = "top"
+      ))
+    ) %>% 
+    ax_grid(
+      show = TRUE,
+      position = "front",
+      borderColor = "#FFF"
+    ) %>% 
+    ax_series(list(
+      name = "Count",
+      data = n_manufac$n
+    )) %>% 
+    ax_colors("#112446") %>% 
+    ax_xaxis(categories = n_manufac$manufacturer) %>% 
+    ax_title(text = "Number of models") %>% 
+    ax_subtitle(text = "Data from ggplot2")
+  
+  
+  expect_is(ax, "apexcharter")
+  expect_true(!is.null(ax$x$ax_opts))
+})