Fixed factor cross ordering

Author: AdamK-A

DESCRIPTION

@@ -38,4 +38,4 @@ Config/testthat/edition: 3
 Encoding: UTF-8
 LazyData: true
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.2

R/cross.R

@@ -32,7 +32,8 @@ fct_cross <- function(..., sep = ":", keep_empty = FALSE) {
   newf <- exec(paste, !!!.data, sep = sep)
 
   old_levels <- lapply(.data, levels)
-  grid <- exec(expand.grid, old_levels)
+  grid_unsorted <- exec(expand.grid, old_levels)
+  grid <- grid_unsorted[do.call(order, grid_unsorted), ]
   new_levels <- exec(paste, !!!grid, sep = sep)
 
   if (!keep_empty) {

tests/testthat/test-cross.R

@@ -71,3 +71,23 @@ test_that("validates its inputs", {
     fct_cross("x", keep_empty = 1)
   })
 })
+
+test_that("Cross factoring 2 levels in order", {
+  f1 <- fct_inorder(c("a4", "a3", "a2", "a1"))
+  f2 <- factor(c("b4", "b3", "b2", "b1"))
+
+  fcross <- fct_cross(f1, f2)
+
+  expect_equal(levels(fcross), c("a4:b4", "a3:b3", "a2:b2", "a1:b1"))
+})
+
+
+test_that("Cross factoring 3 levels in order by first level", {
+  f1 <- fct_inorder(c("a4", "a3", "a2", "a1"))
+  f2 <- factor(c("b4", "b3", "b2", "b1"))
+  f3 <- factor(c("c4", "c3", "c2", "c1"))
+
+  fcross <- fct_cross(f1, f2, f3)
+
+  expect_equal(levels(fcross), c("a4:b4:c4", "a3:b3:c3", "a2:b2:c2", "a1:b1:c1"))
+})