improve error message for fit_xy() when y = NULL (#1064)

Author: simonpcouch

R/fit.R

@@ -438,6 +438,9 @@ check_xy_interface <- function(x, y, cl, model) {
   if (df_interface) {
     return("data.frame")
   }
+
+  check_outcome(y, model)
+
   rlang::abort("Error when checking the interface")
 }
 

tests/testthat/_snaps/misc.md

@@ -167,6 +167,15 @@
       ! `linear_reg()` was unable to find an outcome.
       i Ensure that you have specified an outcome column and that it hasn't been removed in pre-processing.
 
+---
+
+    Code
+      fit_xy(reg_spec, data.frame(x = 1:5), y = NULL)
+    Condition
+      Error:
+      ! `linear_reg()` was unable to find an outcome.
+      i Ensure that you have specified an outcome column and that it hasn't been removed in pre-processing.
+
 ---
 
     Code

tests/testthat/test_misc.R

@@ -220,6 +220,11 @@ test_that('check_outcome works as expected', {
     fit(reg_spec, ~ mpg, mtcars)
   )
 
+  expect_snapshot(
+    error = TRUE,
+    fit_xy(reg_spec, data.frame(x = 1:5), y = NULL)
+  )
+
   class_spec <- logistic_reg()
 
   expect_no_error(