handle {box} recommended method of testing private functions

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: box.linters
 Title: Linters for 'box' Modules
-Version: 0.9.0.9005
+Version: 0.9.0.9006
 Authors@R:
   c(
     person("Ricardo Rodrigo", "Basa", role = c("aut", "cre"), email = "[email protected]"),

NEWS.md

@@ -1,5 +1,6 @@
 # box.linters (development version)
 
+* Handle `box` recommended method of testing private methods.
 * Added handler for `glue` string templates.
 * Added box_mod_fun_exists_linter() to default linters 
 * [bug fix] box_trailing_commas_linter() now properly handles a #nolint for other linters

R/box_unused_attached_mod_linter.R

@@ -83,6 +83,7 @@ box_unused_attached_mod_linter <- function() {
     attached_three_dots <- get_attached_mod_three_dots(xml)
     function_calls <- get_function_calls(xml)
     glue_object_calls <- get_objects_in_strings(xml)
+    possible_module_calls <- get_object_calls(xml)
 
     all_calls_text <- c(function_calls$text, glue_object_calls)
 
@@ -97,8 +98,9 @@ box_unused_attached_mod_linter <- function() {
       )
 
       functions_used <- length(intersect(func_list, all_calls_text))
+      modules_used <- length(intersect(aliased_module_text, possible_module_calls$text))
 
-      if (functions_used == 0) {
+      if (functions_used == 0 && modules_used == 0) {
         lintr::xml_nodes_to_lints(
           attached_module,
           source_expression = source_expression,

tests/testthat/test-box_unused_attached_mod_linter.R

@@ -269,3 +269,41 @@ test_that("box_unused_attached_mod_linter blocks unused objects in glue string t
 
   lintr::expect_lint(bad_box_usage, list(message = lint_message), linters = linter)
 })
+
+
+# Box test interfaces, not implementations
+
+test_that("box_unused_attached_mod_linter skips module call as implementation test", {
+  linter <- box_unused_attached_mod_linter()
+
+  code <- "box::use(
+    path/to/module_a,
+  )
+
+  impl = attr(module_a, \"namespace\")
+
+  test_that(\"implementation detail X works\", {
+    expect_true(impl$a_fun_c())
+  })
+  "
+
+  lintr::expect_lint(code, NULL, linter = linter)
+})
+
+test_that("box_unused_attached_mod_linter blocks unused module call as implementation test", {
+  linter <- box_unused_attached_mod_linter()
+  lint_message <- rex::rex("Attached module unused.")
+
+  code <- "box::use(
+    path/to/module_a,
+  )
+
+  impl = attr(module_b, \"namespace\")
+
+  test_that(\"implementation detail X works\", {
+    expect_true(impl$a_fun_c())
+  })
+  "
+
+  lintr::expect_lint(code, list(message = lint_message), linter = linter)
+})

tests/testthat/test-e2e_testthat.R

@@ -0,0 +1,24 @@
+options(box.path = file.path(getwd(), "mod"))
+
+test_that("all linters skip valid box test for interface", {
+  linters <- lintr::linters_with_defaults(
+    defaults = box.linters::rhino_default_linters
+  )
+
+  code <- "
+box::use(
+  testthat[expect_true, test_that],
+)
+
+box::use(
+  path/to/module_a,
+)
+
+impl <- attr(module_a, \"namespace\")
+
+test_that(\"implementation detail X works\", {
+  expect_true(impl$this_works())
+})"
+
+  lintr::expect_lint(code, NULL, linters = linters)
+})