support tuning postprocessors in workflows

DESCRIPTION

@@ -53,9 +53,10 @@ Config/Needs/website:
     tidyverse/tidytemplate,
     yardstick
 Remotes:
+    tidymodels/dials#358,
     tidymodels/recipes,
     tidymodels/parsnip,
-    tidymodels/tailor,
+    tidymodels/tailor#51,
     r-lib/sparsevctrs
 Config/testthat/edition: 3
 Encoding: UTF-8

R/extract.R

@@ -225,6 +225,13 @@ extract_parameter_set_dials.workflow <- function(x, ...) {
     param_data <- vctrs::vec_rbind(param_data, recipe_param_data)
   }
 
+  if (has_postprocessor_tailor(x)) {
+    tailor <- extract_postprocessor(x)
+    tailor_param_data <- extract_parameter_set_dials(tailor)
+
+    param_data <- vctrs::vec_rbind(param_data, tailor_param_data)
+  }
+
   dials::parameters_constr(
     param_data$name,
     param_data$id,

tests/testthat/_snaps/extract.md

@@ -108,3 +108,12 @@
       Error in `extract_recipe()`:
       ! The workflow must have a recipe preprocessor.
 
+# extract parameter set from workflow with potentially conflicting ids (#266)
+
+    Code
+      extract_parameter_set_dials(wflow)
+    Condition
+      Error in `extract_parameter_set_dials()`:
+      x Element id should have unique values.
+      i Duplicates exist for item: threshold
+

tests/testthat/test-extract.R

@@ -226,6 +226,23 @@ test_that("extract parameter set from workflow with tunable model", {
   expect_true(all(wf_info$source == "model_spec"))
 })
 
+test_that("extract parameter set from workflow with tunable postprocessor", {
+  wflow <- workflow()
+  wflow <- add_recipe(wflow, recipes::recipe(mpg ~ ., mtcars))
+  wflow <- add_model(wflow, parsnip::linear_reg())
+  wflow <- add_tailor(
+    wflow,
+    tailor::tailor() %>%
+    tailor::adjust_numeric_range(lower_limit = hardhat::tune())
+  )
+
+  wflow_info <- extract_parameter_set_dials(wflow)
+
+  check_parameter_set_tibble(wflow_info)
+  expect_equal(nrow(wflow_info), 1)
+  expect_true(all(wflow_info$source == "tailor"))
+})
+
 test_that("extract parameter set from workflow with tunable recipe and model", {
 
   spline_rec <- recipes::recipe(ridership ~ ., data = head(Chicago)) %>%
@@ -252,6 +269,69 @@ test_that("extract parameter set from workflow with tunable recipe and model", {
   )
 })
 
+test_that("extract parameter set from workflow with tunable recipe, model, and tailor", {
+  wflow <- workflow()
+  wflow <- add_recipe(
+    wflow,
+    recipes::recipe(mpg ~ ., mtcars) %>%
+    recipes::step_impute_knn(
+      recipes::all_predictors(),
+      neighbors = hardhat::tune("imputation")
+    )
+  )
+  wflow <- add_model(
+    wflow,
+    parsnip::linear_reg(engine = "glmnet", penalty = tune())
+  )
+  wflow <- add_tailor(
+    wflow,
+    tailor::tailor() %>%
+      tailor::adjust_numeric_range(lower_limit = hardhat::tune())
+  )
+
+  wflow_info <- extract_parameter_set_dials(wflow)
+
+  check_parameter_set_tibble(wflow_info)
+  expect_equal(nrow(wflow_info), 3)
+  expect_true(all(wflow_info$source %in% c("recipe", "model_spec", "tailor")))
+})
+
+test_that("extract parameter set from workflow with potentially conflicting ids (#266)", {
+  # re: https://github.com/tidymodels/workflows/pull/266#issuecomment-2417772184
+  # specifically concerned that duplicated "threshold" parameters result in
+  # an informative error
+  wflow <- workflow()
+  wflow <- add_recipe(
+    wflow,
+    recipes::recipe(mpg ~ ., mtcars) %>%
+    recipes::step_pca(recipes::all_predictors(), threshold = hardhat::tune())
+  )
+  wflow <- add_model(wflow, parsnip::linear_reg())
+  wflow <- add_tailor(
+    wflow,
+    tailor::tailor() %>%
+      tailor::adjust_probability_threshold(threshold = hardhat::tune())
+  )
+
+  expect_snapshot(
+    error = TRUE,
+    extract_parameter_set_dials(wflow)
+  )
+
+  # ensure that the user can actually do something about it
+  wflow <- remove_tailor(wflow)
+  wflow <- add_tailor(
+    wflow,
+    tailor::tailor() %>%
+      tailor::adjust_probability_threshold(threshold = hardhat::tune("unique id"))
+  )
+
+  wflow_info <- extract_parameter_set_dials(wflow)
+
+  check_parameter_set_tibble(wflow_info)
+  expect_equal(nrow(wflow_info), 2)
+  expect_true(all(wflow_info$source %in% c("recipe", "tailor")))
+})
 
 # ------------------------------------------------------------------------------
 # extract_parameter_dials()