Box function import count linter

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: rhino
 Title: A Framework for Enterprise Shiny Applications
-Version: 1.6.0.9005
+Version: 1.6.0.9006
 Authors@R:
   c(
     person("Kamil", "Żyła", role = c("aut", "cre"), email = "[email protected]"),

NAMESPACE

@@ -1,6 +1,7 @@
 # Generated by roxygen2: do not edit by hand
 
 export(app)
+export(box_func_import_count_linter)
 export(box_trailing_commas_linter)
 export(box_universal_import_linter)
 export(build_js)

NEWS.md

@@ -3,6 +3,7 @@
 1. Introduce linters for `box::use` statements:
     * `box_universal_import_linter` checks if all imports are explicit.
     * `box_trailing_commas_linter` checks if statements include trailing commas.
+    * `box_func_import_count_linter` checks if the number of function imports does not exceed the limit.
 2. Major refactor of `rhino::app()`:
     * The `request` parameter is now correctly forwarded to the UI function
     when using a `legacy_entrypoint` ([#395](https://github.com/Appsilon/rhino/issues/395)).

R/box_linters.R

@@ -1,3 +1,72 @@
+#' `box` library function import count linter
+#'
+#' Checks that function imports do not exceed the defined `max`.
+#'
+#' @param max Maximum function imports allowed between `[` and `]`. Defaults to 8.
+#'
+#' @return A custom linter function for use with `r-lib/lintr`.
+#'
+#' @examples
+#' # will produce lints
+#' lintr::lint(
+#'   text = "box::use(package[one, two, three, four, five, six, seven, eight, nine])",
+#'   linters = box_func_import_count_linter()
+#' )
+#'
+#' lintr::lint(
+#'   text = "box::use(package[one, two, three, four])",
+#'   linters = box_func_import_count_linter(3)
+#' )
+#'
+#' # okay
+#' lintr::lint(
+#'   text = "box::use(package[one, two, three, four, five])",
+#'   linters = box_func_import_count_linter()
+#' )
+#'
+#' lintr::lint(
+#'   text = "box::use(package[one, two, three])",
+#'   linters = box_func_import_count_linter(3)
+#' )
+#'
+#' @export
+box_func_import_count_linter <- function(max = 8L) {
+  xpath <- glue::glue("//SYMBOL_PACKAGE[
+                      (text() = 'box' and
+                      following-sibling::SYMBOL_FUNCTION_CALL[text() = 'use'])
+                    ]
+  /parent::expr
+  /parent::expr
+  /descendant::OP-LEFT-BRACKET[
+    count(
+      following-sibling::expr[
+        count(. | ..//OP-RIGHT-BRACKET/preceding-sibling::expr) =
+          count(../OP-RIGHT-BRACKET/preceding-sibling::expr)
+      ]
+    ) > {max}
+  ]
+  /parent::expr")
+
+  lint_message <- glue::glue("Limit the function imports to a max of {max}.")
+
+  lintr::Linter(function(source_expression) {
+    if (!lintr::is_lint_level(source_expression, "file")) {
+      return(list())
+    }
+
+    xml <- source_expression$full_xml_parsed_content
+
+    bad_expr <- xml2::xml_find_all(xml, xpath)
+
+    lintr::xml_nodes_to_lints(
+      bad_expr,
+      source_expression = source_expression,
+      lint_message = lint_message,
+      type = "style"
+    )
+  })
+}
+
 #' `box` library trailing commas linter
 #'
 #' Checks that all `box:use` imports have a trailing comma. This applies to

inst/templates/app_structure/dot.lintr

@@ -1,6 +1,7 @@
 linters:
   linters_with_defaults(
     line_length_linter = line_length_linter(100),
+    box_func_import_count_linter = rhino::box_func_import_count_linter(),
     box_trailing_commas_linter = rhino::box_trailing_commas_linter(),
     box_universal_import_linter = rhino::box_universal_import_linter(),
     object_usage_linter = NULL  # Does not work with `box::use()`.

pkgdown/_pkgdown.yml

@@ -147,6 +147,7 @@ reference:
 
 - title: Linters
   contents:
+  - box_func_import_count_linter
   - box_trailing_commas_linter
   - box_universal_import_linter
 

tests/e2e/app-files/hello.R

@@ -1,5 +1,5 @@
 box::use(
-  shiny[
+  shiny[           # nolint
     actionButton,
     bootstrapPage,
     isolate,

tests/testthat/test-linter_box_func_import_count_linter.R

@@ -0,0 +1,87 @@
+lint_message <- function(max = 5L) {
+  rex::rex(glue::glue("Limit the function imports to a max of {max}."))
+}
+
+test_that("box_func_import_count_linter skips allowed function count.", {
+  linter <- box_func_import_count_linter(max = 5)
+
+  five_function_imports <- "box::use(
+    dplyr[
+      arrange,
+      select,
+      mutate,
+      distinct,
+      filter,
+    ],
+  )"
+
+  five_function_imports_inline <- "box::use(
+    dplyr[arrange, select, mutate, distinct, filter, ],
+  )"
+
+  lintr::expect_lint(five_function_imports, NULL, linter)
+  lintr::expect_lint(five_function_imports_inline, NULL, linter)
+})
+
+test_that("box_func_import_count_linter skips allowed function count supplied max", {
+  linter <- box_func_import_count_linter(max = 3)
+
+  three_function_imports <- "box::use(
+    dplyr[
+      arrange,
+      select,
+      mutate,
+    ],
+  )"
+
+  three_function_imports_inline <- "box::use(
+    dplyr[arrange, select, mutate, ],
+  )"
+
+  lintr::expect_lint(three_function_imports, NULL, linter)
+  lintr::expect_lint(three_function_imports_inline, NULL, linter)
+})
+
+test_that("box_func_import_count_linter blocks function imports more than max", {
+  max <- 5
+  linter <- box_func_import_count_linter(max = max)
+  lint_msg <- lint_message(max)
+
+  six_function_imports <- "box::use(
+    dplyr[
+      arrange,
+      select,
+      mutate,
+      distinct,
+      filter,
+      slice,
+    ],
+  )"
+
+  six_function_imports_inline <- "box::use(
+    dplyr[arrange, select, mutate, distinct, filter, slice, ],
+  )"
+
+  lintr::expect_lint(six_function_imports, list(message = lint_msg), linter)
+  lintr::expect_lint(six_function_imports_inline, list(message = lint_msg), linter)
+})
+
+test_that("box_func_import_count_linter resepect # nolint", {
+  linter <- box_func_import_count_linter()
+
+  no_lint <- "box::use(
+    dplyr[        # nolint
+      arrange,
+      select,
+      mutate,
+      distinct  
+    ],  
+  )"
+
+  no_lint_inline <- "box::use(
+    dplyr[arrange, select, mutate, distinct], # nolint
+  )"
+
+  lintr::expect_lint(no_lint, NULL, linter)
+  lintr::expect_lint(no_lint_inline, NULL, linter)
+})