diff --git a/tests/testthat/test-challenge.R b/tests/testthat/test-challenge.R
new file mode 100644
index 0000000..389a0ef
--- /dev/null
+++ b/tests/testthat/test-challenge.R
@@ -0,0 +1,106 @@
+test_that("missing algorithm performances are added as NA with sanity check enabled for single-task challenge", {
+  data=rbind(
+         data.frame(alg_name="A1", value=0.8, case="C1"),
+         data.frame(alg_name="A2", value=0.6, case="C2")
+       )
+
+  expect_message(actualChallenge <- as.challenge(data, algorithm="alg_name", case="case", value="value", smallBetter=FALSE),
+                 "Performance of not all algorithms is observed for all cases. Inserted as missings in following cases:")
+
+  expectedAlgNames <- c("A1", "A1", "A2", "A2")
+  expectedValues <- c(0.8, NA, NA, 0.6)
+  expectedCases <- c("C1", "C2", "C1", "C2")
+
+  expect_equal(as.vector(actualChallenge$alg_name), expectedAlgNames)
+  expect_equal(as.vector(actualChallenge$value), expectedValues)
+  expect_equal(as.vector(actualChallenge$case), expectedCases)
+})
+
+test_that("missing algorithm performances are not added as NA with sanity check disabled for single-task challenge", {
+  data=rbind(
+         data.frame(alg_name="A1", value=0.8, case="C1"),
+         data.frame(alg_name="A2", value=0.6, case="C2")
+       )
+
+  actualChallenge <- as.challenge(data, algorithm="alg_name", case="case", value="value", smallBetter=FALSE, check=FALSE)
+
+   expectedAlgNames <- c("A1", "A2")
+  expectedValues <- c(0.8, 0.6)
+  expectedCases <- c("C1", "C2")
+
+  expect_equal(as.vector(actualChallenge$alg_name), expectedAlgNames)
+  expect_equal(as.vector(actualChallenge$value), expectedValues)
+  expect_equal(as.vector(actualChallenge$case), expectedCases)
+})
+
+test_that("missing algorithm performances are added as NA with sanity check enabled for multi-task challenge (1 task in data set)", {
+  data=cbind(task="T1",
+             rbind(
+               data.frame(alg_name="A1", value=0.8, case="C1"),
+               data.frame(alg_name="A2", value=0.6, case="C2")
+             ))
+
+  expect_message(actualChallenge <- as.challenge(data, by="task", algorithm="alg_name", case="case", value="value", smallBetter=FALSE),
+                 "Performance of not all algorithms is observed for all cases in task T1. Inserted as missings in following cases:")
+
+  expectedAlgNames <- c("A1", "A1", "A2", "A2")
+  expectedValues <- c(0.8, NA, NA, 0.6)
+  expectedCases <- c("C1", "C2", "C1", "C2")
+
+  expect_equal(as.vector(actualChallenge$T1$alg_name), expectedAlgNames)
+  expect_equal(as.vector(actualChallenge$T1$value), expectedValues)
+  expect_equal(as.vector(actualChallenge$T1$case), expectedCases)
+})
+
+test_that("missing algorithm performances are not added as NA with sanity check disabled for multi-task challenge (1 task in data set)", {
+  data=cbind(task="T1",
+             rbind(
+               data.frame(alg_name="A1", value=0.8, case="C1"),
+               data.frame(alg_name="A2", value=0.6, case="C2")
+             ))
+
+  actualChallenge <- as.challenge(data, by="task", algorithm="alg_name", case="case", value="value", smallBetter=FALSE, check=FALSE)
+
+  expectedAlgNames <- c("A1", "A2")
+  expectedValues <- c(0.8, 0.6)
+  expectedCases <- c("C1", "C2")
+
+  expect_equal(as.vector(actualChallenge$alg_name), expectedAlgNames)
+  expect_equal(as.vector(actualChallenge$value), expectedValues)
+  expect_equal(as.vector(actualChallenge$case), expectedCases)
+})
+
+test_that("missing algorithm performances are added as NA with sanity check enabled for multi-task challenge (2 tasks in data set)", {
+  dataT1=cbind(task="T1",
+               rbind(
+                 data.frame(alg_name="A1", value=0.8, case="C1"),
+                 data.frame(alg_name="A2", value=0.6, case="C2")
+               ))
+  dataT2=cbind(task="T2",
+               rbind(
+                 data.frame(alg_name="A1", value=0.2, case="C1"),
+                 data.frame(alg_name="A1", value=0.3, case="C2"),
+                 data.frame(alg_name="A2", value=0.4, case="C1")
+               ))
+
+  data=rbind(dataT1, dataT2)
+
+  expect_message(actualChallenge <- as.challenge(data, by="task", algorithm="alg_name", case="case", value="value", smallBetter=FALSE),
+                 "Performance of not all algorithms is observed for all cases in task T1. Inserted as missings in following cases:")
+
+  expectedAlgNamesT1 <- c("A1", "A1", "A2", "A2")
+  expectedValuesT1 <- c(0.8, NA, NA, 0.6)
+  expectedCasesT1 <- c("C1", "C2", "C1", "C2")
+
+  expect_equal(as.vector(actualChallenge$T1$alg_name), expectedAlgNamesT1)
+  expect_equal(as.vector(actualChallenge$T1$value), expectedValuesT1)
+  expect_equal(as.vector(actualChallenge$T1$case), expectedCasesT1)
+
+  expectedAlgNamesT2 <- c("A1", "A1", "A2", "A2")
+  expectedValuesT2 <- c(0.2, 0.3, 0.4, NA)
+  expectedCasesT2 <- c("C1", "C2", "C1", "C2")
+
+  expect_equal(as.vector(actualChallenge$T2$alg_name), expectedAlgNamesT2)
+  expect_equal(as.vector(actualChallenge$T2$value), expectedValuesT2)
+  expect_equal(as.vector(actualChallenge$T2$case), expectedCasesT2)
+})