diff --git a/tests/testthat/test-adjustedKm.R b/tests/testthat/test-adjustedKm.R
new file mode 100644
index 00000000..92e25d1f
--- /dev/null
+++ b/tests/testthat/test-adjustedKm.R
@@ -0,0 +1,97 @@
+library(testthat)
+library(CohortMethod)
+
+weights <- seq(100)*10^-3
+times <- seq(100)
+ys0 <- rep(0, 100)
+ys1 <- rep(1, 100)
+
+
+test_that("Void", {
+  expect_error(adjustedKm())
+})
+
+# Parameter Sweep
+test_that("Minimal", {
+  res <- adjustedKm(weight = weights, time = times, y = ys1)
+
+  expect_equal(nrow(res), 100)
+  expect_equal(ncol(res), 3)
+  expect_equal(names(res), c("time", "s", "var"))
+})
+
+test_that("Numeric types", {
+  res <- adjustedKm(1, 1, 1)
+  expect_equal(res, data.frame(time = 1, s = 0, var = 0))
+
+  res <- adjustedKm(0, 0, 0)
+  expect_equal(res, data.frame(time = 0, s = NaN, var = NaN))
+
+  res <- adjustedKm(-1, -1, -1)
+  expect_equal(res, data.frame(time = -1, s = 1, var = 0))
+})
+
+test_that("weight", {
+  expect_error(
+    adjustedKm("1", 1, 1),
+    "type=character; target=double"
+  )
+
+  # Upper bounds
+  res <- adjustedKm(2147483648, 1, 1)
+  expect_equal(res, data.frame(time = 1, s = 0, var = 0))
+
+  res <- adjustedKm(9*10^300, 1, 1)
+  expect_equal(res, data.frame(time = 1, s = 0, var = NaN))
+
+  res <- adjustedKm(9*10^999, 1, 1)
+  expect_equal(res, data.frame(time = 1, s = NaN, var = NaN))
+
+  # Lower bounds
+  res <- adjustedKm(-2147483648, 1, 1)
+  expect_equal(res, data.frame(time = 1, s = 0, var = 0))
+
+  res <- adjustedKm(-9*10^300, 1, 1)
+  expect_equal(res, data.frame(time = 1, s = 0, var = NaN))
+
+  res <- adjustedKm(-9*10^999, 1, 1)
+  expect_equal(res, data.frame(time = 1, s = NaN, var = NaN))
+})
+
+test_that("time", {
+  expect_error(
+    adjustedKm(1, "1", 1),
+    "type=character; target=integer"
+  )
+
+  # Upper bounds
+  res <- adjustedKm(1, 2147483647, 1)
+  expect_equal(res, data.frame(time = 2147483647, s = 0, var = 0))
+
+  expect_warning(adjustedKm(1, 2147483648, 1))
+
+  # Lower bounds
+  res <- adjustedKm(1, -2147483647, 1)
+  expect_equal(res, data.frame(time = -2147483647, s = 0, var = 0))
+
+  expect_warning(adjustedKm(1, -2147483648, 1))
+})
+
+test_that("var", {
+  expect_error(
+    adjustedKm(1, 1, "1"),
+    "type=character; target=integer"
+  )
+
+  # Upper bounds
+  res <- adjustedKm(1, 1, 2147483647)
+  expect_equal(res, data.frame(time = 1, s = 1, var = 0))
+
+  expect_warning(adjustedKm(1, 1, 2147483648))
+
+  # Lower bounds
+  res <- adjustedKm(1, 1, -2147483647)
+  expect_equal(res, data.frame(time = 1, s = 1, var = 0))
+
+  expect_warning(adjustedKm(1, -2147483648, 1))
+})