Merge pull request #79 from tidymodels/backwards-json

make orbital_json_* functions backwards compatible

R/json.R

@@ -40,7 +40,12 @@
 orbital_json_write <- function(x, path) {
 	actions <- as.list(unclass(x))
 
-	res <- list(actions = actions, version = 1)
+	res <- list(
+		actions = actions,
+		pred_names = attr(x, "pred_names"),
+		version = 2
+	)
+
 	res <- jsonlite::toJSON(res, pretty = TRUE, auto_unbox = TRUE)
 
 	writeLines(res, path)
@@ -85,9 +90,17 @@ orbital_json_write <- function(x, path) {
 orbital_json_read <- function(path) {
 	rlang::check_installed("jsonlite")
 
-	res <- jsonlite::read_json(path)
+	json <- jsonlite::read_json(path)
+
+	version <- json$version
 
-	res <- unlist(res$actions)
+	if (version == 1) {
+		res <- unlist(json$actions)
+		attr(res, "pred_names") <- utils::tail(names(res), 1)
+	} else if (version == 2) {
+		res <- unlist(json$actions)
+		attr(res, "pred_names") <- json$pred_names
+	}
 
 	new_orbital_class(res)
 }

tests/testthat/test-json.R

@@ -20,8 +20,37 @@ test_that("read and write json works", {
 
 	new <- orbital_json_read(tmp_file)
 
-	# temp fix
-	attr(orbital_obj, "pred_names") <- NULL
+	expect_identical(new, orbital_obj)
+})
+
+test_that("read and write json works - backwards from version 1", {
+	skip_if_not_installed("recipes")
+	skip_if_not_installed("tidypredict")
+	skip_if_not_installed("jsonlite")
+	skip_if_not_installed("workflows")
+	rec_spec <- recipes::recipe(mpg ~ ., data = mtcars) %>%
+		recipes::step_normalize(recipes::all_numeric_predictors())
+
+	lm_spec <- parsnip::linear_reg()
+
+	wf_spec <- workflows::workflow(rec_spec, lm_spec)
+
+	wf_fit <- parsnip::fit(wf_spec, mtcars)
+
+	orbital_obj <- orbital(wf_fit)
+
+	tmp_file <- tempfile()
+
+	orbital_json_write(orbital_obj, tmp_file)
+
+	# Fake version 1
+	fake_json <- jsonlite::read_json(tmp_file)
+	fake_json$pred_names <- NULL
+	fake_json$version <- 1
+	fake_json <- jsonlite::toJSON(fake_json, pretty = TRUE, auto_unbox = TRUE)
+	writeLines(fake_json, tmp_file)
+
+	new <- orbital_json_read(tmp_file)
 
 	expect_identical(new, orbital_obj)
 })