Make fit_xy() fail when mode is unknown (#801)

* Make fit_xy() fail when mode is unknown

* remove check_mode()

* revert Rproj option

Author: topepo

NEWS.md

@@ -2,6 +2,8 @@
 
 * Fixed installation failures due to undocumented knitr installation dependency (#785).
 
+* `fit_xy()` now fails when the model mode is unknown. 
+
 # parsnip 1.0.1
 
 * Enabled passing additional engine arguments with the xgboost `boost_tree()` engine. To supply engine-specific arguments that are documented in `xgboost::xgb.train()` as arguments to be passed via `params`, supply the list elements directly as named arguments to `set_engine()`. Read more in `?details_boost_tree_xgboost` (#787).

R/fit.R

@@ -228,6 +228,10 @@ fit_xy.model_spec <-
            control = control_parsnip(),
            ...
   ) {
+    if (object$mode == "unknown") {
+      rlang::abort("Please set the mode in the model specification.")
+    }
+
     if (object$mode == "censored regression") {
       rlang::abort("Models for censored regression must use the formula interface.")
     }
@@ -244,7 +248,6 @@ fit_xy.model_spec <-
     }
     check_case_weights(case_weights, object)
 
-    object <- check_mode(object, levels(y))
     dots <- quos(...)
     if (is.null(object$engine)) {
       eng_vals <- possible_engines(object)

R/fit_helpers.R

@@ -12,7 +12,6 @@ form_form <-
 
     # prob rewrite this as simple subset/levels
     y_levels <- levels_from_formula(env$formula, env$data)
-    object <- check_mode(object, y_levels)
 
     # if descriptors are needed, update descr_env with the calculated values
     if (requires_descrs(object)) {
@@ -64,7 +63,6 @@ xy_xy <- function(object, env, control, target = "none", ...) {
   if (inherits(env$x, "tbl_spark") | inherits(env$y, "tbl_spark"))
     rlang::abort("spark objects can only be used with the formula interface to `fit()`")
 
-  object <- check_mode(object, levels(env$y))
   check_outcome(env$y, object)
 
   encoding_info <-

R/translate.R

@@ -97,17 +97,6 @@ translate.default <- function(x, engine = x$engine, ...) {
   x
 }
 
-check_mode <- function(object, lvl) {
-  if (object$mode == "unknown") {
-    if (!is.null(lvl)) {
-      object$mode <- "classification"
-    } else {
-      object$mode <- "regression"
-    }
-  }
-  object
-}
-
 # ------------------------------------------------------------------------------
 # new code for revised model data structures
 

tests/testthat/test_fit_interfaces.R

@@ -66,11 +66,11 @@ test_that('unknown modes', {
   )
   expect_error(
     fit_xy(mars_spec, x = mtcars[, -1], y = mtcars[,1]),
-    regexp = NA
+    regexp = "Please set the mode in the model specification."
   )
   expect_error(
     fit_xy(mars_spec, x = lending_club[,1:2], y = lending_club$Class),
-    regexp = NA
+    regexp = "Please set the mode in the model specification."
   )
 })