diff --git a/DESCRIPTION b/DESCRIPTION
index a73fe22..8158b40 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -26,5 +26,6 @@ Imports:
     lifecycle,
     janitor
 Suggests: 
-    testthat (>= 3.0.0)
+    testthat (>= 3.0.0),
+    withr
 Config/testthat/edition: 3
diff --git a/SQLRtools.Rproj b/SQLRtools.Rproj
index 21a4da0..3cec3bb 100644
--- a/SQLRtools.Rproj
+++ b/SQLRtools.Rproj
@@ -1,4 +1,5 @@
 Version: 1.0
+ProjectId: e2646519-d824-45f7-8bd6-885d2b38f559
 
 RestoreWorkspace: Default
 SaveWorkspace: Default
diff --git a/tests/testthat/test-get_env_var.R b/tests/testthat/test-get_env_var.R
new file mode 100644
index 0000000..3196eb5
--- /dev/null
+++ b/tests/testthat/test-get_env_var.R
@@ -0,0 +1,50 @@
+test_that("returns an expected password as if it were from keyring", {
+  local_mocked_bindings(
+    get_env_var = function(var_name) {
+      service = "GLOBAL-SETTING"
+      username = "keyring_words"
+      return(list(var_name = service, username = username))
+    }
+  )
+  
+  # Call the function
+  result <- SQLRtools::get_env_var(var_name = "GLOBAL-SETTING")
+  
+  # Check the result
+  expect_equal(result$username, "keyring_words")
+  expect_equal(result$var_name, "GLOBAL-SETTING")
+  
+})
+
+test_that("returns message when not keyring is not set up", {
+   
+  testthat::expect_error(
+    get_env_var(var_name = "Something"),
+    "variable Something not found using keyring or Sys.getenv()"
+  ) 
+
+}) 
+
+
+test_that("warning if string from Sys.getenv but username is not rstudio-connect", {
+
+  withr::local_envvar(c("USERNAME" = "something-connect"))
+  withr::local_envvar(c("GLOBAL_SETTING" = "system_words"))
+
+  expect_warning(
+    SQLRtools::get_env_var(var_name = "GLOBAL_SETTING"),
+    "found in Renviron file but not windows credentials"
+  )
+})
+
+test_that("returns string when username is rstudio-connect", {
+  
+  withr::local_envvar(c("USERNAME" = "rstudio-connect"))
+  withr::local_envvar(c("GLOBAL_SETTING" = "system_words"))
+
+  # Check the result
+  expect_equal(SQLRtools::get_env_var(var_name = "GLOBAL_SETTING"), "system_words")
+  
+})
+
+
diff --git a/tests/testthat/test-sql_server.R b/tests/testthat/test-sql_server.R
new file mode 100644
index 0000000..322d90b
--- /dev/null
+++ b/tests/testthat/test-sql_server.R
@@ -0,0 +1,97 @@
+test_that("expect R6 class object", {
+  local_mocked_bindings(
+    sql_server = function(driver,
+                          server,
+                          database,
+                          port,
+                          uid,
+                          pwd) {
+      driver = "MySQL ODBC 8.0 Unicode Driver"
+      server = "HOST_NAME"
+      database = "MYSQL_DB"
+      port = "MYSQL_PORT"
+      uid = "MYSQL_USER"
+      pwd = "MYSQL_PASSWORD"
+      return(R6Class("Test",
+                    public = list(driver = driver,
+                  server = server,
+                  database = database,
+                  port = port,
+                  uid = uid,
+                  pwd = pwd)
+                  ))
+    })
+    
+    mysql_serv_mock <- sql_server(driver = "MySQL ODBC 8.0 Unicode Driver",
+                                 server = "HOST_NAME",
+                                 database = "MYSQL_DB",
+                                 port = "MYSQL_PORT",
+                                 uid = "MYSQL_USER",
+                                 pwd = "MYSQL_PASSWORD")
+    
+    mysql_serv_NULL <- sql_server(driver = NULL,
+                             server = NULL,
+                             database = NULL,
+                             port = NULL,
+                             uid = NULL,
+                             pwd = NULL)
+
+    expect_true(is.R6Class(mysql_serv_mock))
+    expect_true(is.R6Class(mysql_serv_NULL))
+    expect_error(mysql_serv_mock$new(), NA)
+    expect_error(mysql_serv_NULL$new(), NA)
+})
+
+
+test_that("expect message when drop_table used as no table exists", {
+  local_mocked_bindings(
+    sql_server = function(driver,
+                          server,
+                          database,
+                          port,
+                          uid,
+                          pwd,
+                          table_name) {
+      driver = "driver"
+      server = "HOST_NAME"
+      database = "MYSQL_DB"
+      port = "MYSQL_PORT"
+      uid = "MYSQL_USER"
+      pwd = "MYSQL_PASSWORD"
+      table_name = NULL
+      return(R6Class("Test",
+                     public = list(driver = driver,
+                                   server = server,
+                                   database = database,
+                                   port = port,
+                                   uid = uid,
+                                   pwd = pwd,
+                                   table_name = table_name)
+      ))
+    })
+  
+  # create vector
+  test_table_name <- "SQLRtools_test_table"
+
+  # create dummy data using dittodb
+  test_data <- data.frame(Int_field = 1:200,
+                          char_field_1 = stri_rand_strings(200, sample(5:11, 5, replace = TRUE), '[a-zA-Z]'),
+                          char_field_2 = stri_rand_strings(200, sample(5:11, 5, replace = TRUE), '[a-zA-Z]'),
+                          date_field = sample(seq(as.Date('2018/01/01'), as.Date('2024/01/01'), by = "day"), 200),
+                          date_time_field = sample(seq(as_datetime('2018-01-01 00:00:00'),
+                                                       as_datetime('2024-01-01 00:00:00'),
+                                                       by = "min"), 200))
+
+  mysql_serv_mock <- sql_server(driver = "driver",
+                           server = "HOST_NAME",
+                           database = "MYSQL_DB",
+                           port = "MYSQL_PORT",
+                           uid = "MYSQL_USER",
+                           pwd = "MYSQL_PASSWORD",
+                           table_name = NULL)
+  
+  expect_message(mysql_serv$drop_table(test_table_name), "table SQLRtools_test_table doesn't exist")
+  
+})
+
+