more thorough transformer dropping testing

Author: lorenzwalthert

R/style-guides.R

@@ -357,6 +357,8 @@ create_style_guide <- function(initialize = default_style_guide_attributes,
 #'   circumstances the transformer does not have an impact on styling and can
 #'   therefore be safely removed without affecting the styling outcome.
 #'
+#' You can use the un-exported function [test_transformers_dropping()] for some
+#' checks.
 #' @examples
 #' dropping <- specify_transformer_dropping(
 #'   spaces = c(remove_space_after_excl = "'!'")

R/testing.R

@@ -341,3 +341,26 @@ fresh_testthat_cache <- function() {
 cache_more_specs_default <- function() {
   cache_more_specs(include_roxygen_examples = TRUE, base_indention = 0)
 }
+
+#' Check if the transformers_dropping in [create_style_guide()] is consistent
+#' with the transformers specified.
+#' @param transformers The output of [create_style_guide()] we want to test.
+#' @keywords internal
+test_transformers_dropping <- function(transformers) {
+  scopes <- intersect(
+    names(transformers$transformers_drop),
+    names(transformers)
+  )
+
+  purrr::walk2(transformers$transformers_drop, transformers[scopes], function(x, y) {
+    # all x must be in y. select the x that are not in y
+    diff <- setdiff(names(x), names(y))
+    if (length(diff) > 0) {
+      rlang::abort(paste(
+        "transformer_dropping specifies exclusion rules for transformers that ",
+        "are not in the style guilde. Please add the rule to the style guide ",
+        "or remove the dropping rules:", paste(diff, collapse = ", ")
+      ))
+    }
+  })
+}

man/test_transformers_dropping.Rd

@@ -26,3 +26,26 @@ test_that("properly detects match", {
     "identical"
   )
 })
+
+test_that('detects non-matching style guides', {
+  sg <- create_style_guide(
+    space = list(
+      a1 = function(...) NULL,
+      b1 = function(... ) 1
+    ),
+    transformers_drop = specify_transformer_dropping(
+      spaces = c(a1 = "'+'")
+    )
+  )
+  expect_silent(test_transformers_dropping(sg))
+
+  sg <- create_style_guide(
+    space = list(
+      a1 = function(...) NULL
+    ),
+    transformers_drop = specify_transformer_dropping(
+      spaces = c(a2 = "'+'")
+    )
+  )
+  expect_error(test_transformers_dropping(sg))
+})

tests/testthat/test-serialize_tests.R

@@ -9,7 +9,9 @@ remove_space_after_excl_ <- function(pd_flat) {
 
 t <- create_style_guide(
   space = lst(remove_space_after_excl_),
-  transformers_drop = list(space = list(remove_space_after_excl_ = c("'!'"))),
+  transformers_drop = specify_transformer_dropping(
+    spaces = list(remove_space_after_excl_ = c("'!'"))
+  ),
   style_guide_name = "styler::t@https://github.com/r-lib",
   style_guide_version = as.character(packageVersion("styler"))
 )
@@ -45,28 +47,18 @@ test_that("transformers are removed if they are unused", {
   expect_equal(t_fun, t_manual)
 })
 
+test_that("tidyverse transformers are correctly named", {
+  # test that all dropping rules match an actual rule in the style guide
+  expect_silent(
+    test_transformers_dropping(tidyverse_style())
+  )
+})
+
 test_that("tidyverse transformers are correctly dropped", {
+  # TODO maybe there is a more minimal test than this.
   t_style <- tidyverse_style()
+  t_fun <- transformers_drop("x", t_style)
 
-  t_fun <- transformers_drop(
-    "x", t_style
-  )
-  # test that all dropping rules match an actual rule in the style guide
-  scopes <- intersect(
-    names(t_fun$transformers_drop),
-    names(t_fun)
-  )
-  purrr::map2(t_fun$transformers_drop, t_style[scopes], function(x, y) {
-    # all x must be in y. select the x that are not in y
-    diff <- setdiff(names(x),names(y))
-    if (length(diff) > 0) {
-      rlang::abort(paste(
-        "transformer_dropping specifies exclusion rules for transformers that ",
-        "are not in the style guilde. Please add the rule to the style guide ",
-        "or remove the dropping rules:", paste(diff, collapse = ", "))
-      )
-    }
-  })
   names_line_break <- c(
     "set_line_break_around_comma_and_or",
     "set_line_break_after_assignment",
@@ -97,7 +89,6 @@ test_that("tidyverse transformers are correctly dropped", {
     "remove_terminal_token_before_and_after"
   )
   expect_setequal(names(t_fun$token), names_tokens)
-
 })