Re-export required_pkgs generic and added parsnip methods

DESCRIPTION

@@ -1,5 +1,5 @@
 Package: parsnip
-Version: 0.1.5.9001
+Version: 0.1.5.9002
 Title: A Common API to Modeling and Analysis Functions
 Description: A common interface is provided to allow users to specify a model without having to remember the different argument names across different functions or computational engines (e.g. 'R', 'Spark', 'Stan', etc). 
 Authors@R: c(

NAMESPACE

@@ -62,6 +62,8 @@ S3method(print,svm_poly)
 S3method(print,svm_rbf)
 S3method(req_pkgs,model_fit)
 S3method(req_pkgs,model_spec)
+S3method(required_pkgs,model_fit)
+S3method(required_pkgs,model_spec)
 S3method(tidy,"_elnet")
 S3method(tidy,"_fishnet")
 S3method(tidy,"_lognet")
@@ -175,6 +177,7 @@ export(prepare_data)
 export(rand_forest)
 export(repair_call)
 export(req_pkgs)
+export(required_pkgs)
 export(rpart_train)
 export(set_args)
 export(set_dependency)
@@ -228,6 +231,7 @@ importFrom(generics,augment)
 importFrom(generics,fit)
 importFrom(generics,fit_xy)
 importFrom(generics,glance)
+importFrom(generics,required_pkgs)
 importFrom(generics,tidy)
 importFrom(generics,varying_args)
 importFrom(glue,glue_collapse)

NEWS.md

@@ -1,5 +1,7 @@
 # parsnip (development version)
 
+* `generics::required_pkgs()` was extended for `parsnip` objects. 
+
 * The `liquidSVM` engine for `svm_rbf()` was deprecated due to that package's removal from CRAN. (#425)
 
 * A new linear SVM model `svm_linear()` is now available with the `LiblineaR` engine (#424) and the `kernlab` engine (#438), and the `LiblineaR` engine is available for `logistic_reg()` as well (#429).

R/reexports.R

@@ -22,3 +22,7 @@ generics::glance
 #' @importFrom generics augment
 #' @export
 generics::augment
+
+#' @importFrom generics required_pkgs
+#' @export
+generics::required_pkgs

R/req_pkgs.R

@@ -4,9 +4,9 @@
 #' @param ... Not used.
 #' @return A character string of package names (if any).
 #' @details
-#' For a model specification, the engine must be set.
-#'
-#' The list does not include the `parsnip` package.
+#' For a model specification, the engine must be set. The list produced by
+#' `req_pkgs()`does not include the `parsnip` package while `required_pkgs()`
+#' does.
 #' @examples
 #' should_fail <- try(req_pkgs(linear_reg()), silent = TRUE)
 #' should_fail
@@ -51,3 +51,16 @@ get_pkgs <- function(x) {
   res
 }
 
+#' @export
+#' @rdname req_pkgs
+required_pkgs.model_spec <- function(x, ...) {
+  res <- req_pkgs.model_spec(x, ...)
+  sort(unique(c("parsnip", res)))
+}
+
+#' @export
+#' @rdname req_pkgs
+required_pkgs.model_fit <- function(x, ...) {
+  res <- req_pkgs.model_fit(x, ...)
+  sort(unique(c("parsnip", res)))
+}

R/zzz.R

@@ -9,6 +9,8 @@
   s3_register("generics::tidy", "_fishnet")
   s3_register("generics::glance", "model_fit")
   s3_register("generics::augment", "model_fit")
+  s3_register("generics::required_pkgs", "model_fit")
+  s3_register("generics::required_pkgs", "model_spec")
 }
 
 

tests/testthat/test_packages.R

@@ -7,19 +7,21 @@ load(test_path("mars_model.RData"))
 test_that('required packages', {
 
   expect_error(req_pkgs(linear_reg()), "Please set an engine")
+  expect_error(required_pkgs(linear_reg()), "Please set an engine")
 
   glmn <-
     linear_reg() %>%
-    set_engine("glmnet") %>%
-    req_pkgs()
-  expect_equal(glmn, "glmnet")
+    set_engine("glmnet")
+  expect_equal(req_pkgs(glmn), "glmnet")
+  expect_equal(required_pkgs(glmn), c("glmnet", "parsnip"))
+
 
   lm_fit <-
     linear_reg() %>%
     set_engine("lm") %>%
-    fit(mpg ~ ., data = mtcars) %>%
-    req_pkgs()
-  expect_equal(lm_fit, "stats")
+    fit(mpg ~ ., data = mtcars)
+  expect_equal(req_pkgs(lm_fit), "stats")
+  expect_equal(required_pkgs(lm_fit), c("parsnip", "stats"))
 })
 
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