diff --git a/base/visualization/DESCRIPTION b/base/visualization/DESCRIPTION
index 201bffdada4..2aece439bdd 100644
--- a/base/visualization/DESCRIPTION
+++ b/base/visualization/DESCRIPTION
@@ -42,10 +42,12 @@ Imports:
     stringr(>= 1.1.0)
 Suggests:
     grid,
+    mockery,
     png,
     raster,
     sp,
-    testthat (>= 1.0.2)
+    testthat (>= 1.0.2),
+    withr
 License: BSD_3_clause + file LICENSE
 Copyright: Authors
 LazyLoad: yes
diff --git a/base/visualization/R/plots.R b/base/visualization/R/plots.R
index f93f3eacf10..3f1395305bc 100644
--- a/base/visualization/R/plots.R
+++ b/base/visualization/R/plots.R
@@ -188,7 +188,7 @@ iqr <- function(x) {
 ##'
 ##' Used to add raw data or summary statistics to the plot of a distribution.
 ##' The height of Y is arbitrary, and can be set to optimize visualization.
-##' If SE estimates are available, the se wil be plotted
+##' If SE estimates are available, the SE will be plotted
 ##' @name plot_data
 ##' @aliases plot.data
 ##' @title Add data to plot 
diff --git a/base/visualization/man/plot_data.Rd b/base/visualization/man/plot_data.Rd
index b54ad1dbca8..37d741dbd0b 100644
--- a/base/visualization/man/plot_data.Rd
+++ b/base/visualization/man/plot_data.Rd
@@ -24,7 +24,7 @@ Add data to an existing plot or create a new one
 \details{
 Used to add raw data or summary statistics to the plot of a distribution.
 The height of Y is arbitrary, and can be set to optimize visualization.
-If SE estimates are available, the se wil be plotted
+If SE estimates are available, the SE will be plotted
 }
 \examples{
 \dontrun{plot_data(data.frame(Y = c(1, 2), se = c(1,2)), base.plot = NULL, ymax = 10)}
diff --git a/base/visualization/tests/testthat/data/urbana_subdaily_test.nc b/base/visualization/tests/testthat/data/urbana_subdaily_test.nc
new file mode 100644
index 00000000000..3e7ceef3671
Binary files /dev/null and b/base/visualization/tests/testthat/data/urbana_subdaily_test.nc differ
diff --git a/base/visualization/tests/testthat/test.add_icon.R b/base/visualization/tests/testthat/test.add_icon.R
new file mode 100644
index 00000000000..d487b87714e
--- /dev/null
+++ b/base/visualization/tests/testthat/test.add_icon.R
@@ -0,0 +1,7 @@
+test_that("`add_icon()` able to create the correct output file", {
+  withr::with_dir(tempdir(), {
+    add_icon(1, 2, 3)
+    # check if file exists
+    expect_true(file.exists("Rplots.pdf"))
+  })
+})
\ No newline at end of file
diff --git a/base/visualization/tests/testthat/test.plot_data.R b/base/visualization/tests/testthat/test.plot_data.R
new file mode 100644
index 00000000000..25264be0474
--- /dev/null
+++ b/base/visualization/tests/testthat/test.plot_data.R
@@ -0,0 +1,7 @@
+test_that("`plot_data()` able to create a new plot for data passed to it", {
+  withr::with_dir(tempdir(), {
+    res <- plot_data(data.frame(Y = c(1, 2), se = c(1,2), trt = c(1, 2)), base.plot = NULL, ymax = 10)
+    print(res)
+    expect_true(file.exists(paste0(getwd(), "/Rplots.pdf")))
+  })
+})
\ No newline at end of file
diff --git a/base/visualization/tests/testthat/test.plot_netcdf.R b/base/visualization/tests/testthat/test.plot_netcdf.R
new file mode 100644
index 00000000000..c0e32252adc
--- /dev/null
+++ b/base/visualization/tests/testthat/test.plot_netcdf.R
@@ -0,0 +1,21 @@
+test_that("`data.fetch()` able to return aggregated data with the correct label", {
+  nc <- ncdf4::nc_open("./data/urbana_subdaily_test.nc")
+  on.exit(ncdf4::nc_close(nc))
+  
+  res <- data.fetch("time", nc, mean)
+  expect_equal(attr(res, "lbl"), "days since 1700-01-01T00:00:00Z")
+
+  res <- data.fetch("air_temperature", nc, mean)
+  expect_equal(attr(res, "lbl"), "3-hourly Air Temperature at 2m in K")
+})
+
+test_that("`plot_netcdf()` able to correctly plot the netcdf file data and create the plot file at the desired location", {
+  nc <- ncdf4::nc_open("./data/urbana_subdaily_test.nc")
+  withr::with_dir(tempdir(), {
+    mockery::stub(plot_netcdf, 'ncdf4::nc_open', nc)
+    res <- plot_netcdf("./data/urbana_subdaily_test.nc", "time", "air_temperature", year = 2010)
+
+    # check if file exists
+    expect_true(file.exists("Rplots.pdf"))
+  })
+})
\ No newline at end of file