inc_prop only returned ae=1 var=0 on certain platforms. (#22)

* inc_prop only returned ae=1 var=0 on certain platforms. Issue is fixed now.

testthat has been updated to match structure of other tests

* Update R/inc_prop.R

Co-authored-by: Daniel Sabanes Bove <danielinteractive@users.noreply.github.com>

---------

Co-authored-by: Kuenzel <kuenzelt@emea.roche.com>
Co-authored-by: Daniel Sabanes Bove <danielinteractive@users.noreply.github.com>

R/inc_prop.R

@@ -37,7 +37,7 @@ inc_prop <- function(data,
   assert_true(tau > 0)
 
   n <- nrow(data)
-  ae <- nrow(data["type_of_event" == 1 & "time_to_event" <= tau]) / n
+  ae <- sum(data$type_of_event == 1 & data$time_to_event <= tau) / n
   ae_prob_var <- ae * (1 - ae) / n
 
   c("ae_prob" = ae, "ae_prob_var" = ae_prob_var)

tests/testthat/test-inc_prop.R

@@ -1,13 +1,13 @@
 test_that("inc_prop works as expected", {
-  set.seed(123)
-  result <- generate_data(
-    n = 10,
-    cens = c(0, 0.5),
-    haz_ae = 4.3,
-    haz_death = 5.3,
-    haz_soft = 1.2
+  set.seed(23)
+  df <- generate_data(
+    n = 25,
+    cens = c(0.2, 3),
+    haz_ae = 0.2,
+    haz_death = 0.3,
+    haz_soft = 0.5
   )
-  ip <- inc_prop(data = result, tau = 4)
-  expect_vector(ip, size = 2)
-  expect_named(ip, c("ae_prob", "ae_prob_var"))
+  result <- inc_prop(data = df, tau = 4)
+  expected <- c(ae_prob = 0.2, ae_prob_var = 0.0064)
+  expect_equal(result, expected, tolerance = 1e-4)
 })