set structure() as an undesirable function by default (#2228)

.lintr

@@ -31,7 +31,7 @@ linters: linters_with_defaults(
     sort_linter(),
     sprintf_linter(),
     strings_as_factors_linter(),
-    undesirable_function_linter(c(Sys.setenv = NA_character_, mapply = NA_character_)),
+    undesirable_function_linter(c(Sys.setenv = NA_character_, mapply = NA_character_, structure = NA_character_)),
     unnecessary_nested_if_linter(),
     unnecessary_lambda_linter(),
     unnecessary_concatenation_linter(allow_single_expression = FALSE),

NEWS.md

@@ -52,7 +52,7 @@
 * `unreachable_code_linter()` checks for code inside `if (FALSE)` and other conditional loops with deterministically false conditions (#1428, @ME0265).
 * `implicit_assignment_linter()` gains an argument `allow_lazy` (default `FALSE`) that allows optionally skipping lazy assignments like `A && (B <- foo(A))` (#2016, @MichaelChirico).
 * `unused_import_linter()` gains an argument `interpret_glue` (default `TRUE`) paralleling that in `object_usage_linter()` to toggle whether `glue::glue()` expressions should be inspected for exported object usage (#2042, @MichaelChirico).
-* `default_undesirable_functions` is updated to also include `Sys.unsetenv()` (#2192, @IndrajeetPatil).
+* `default_undesirable_functions` is updated to also include `Sys.unsetenv()` and `structure()` (#2192 and #2228, @IndrajeetPatil and @MichaelChirico).
 * Linters with logic around the magrittr pipe `%>%` consistently apply it to the other pipes `%!>%`, `%T>%`, `%<>%` (and possibly `%$%`) where appropriate (#2008, @MichaelChirico).
   + `brace_linter()`
   + `pipe_call_linter()`

R/zzz.R

@@ -171,7 +171,9 @@ all_undesirable_functions <- modify_defaults(
   untrace = paste(
     "remove this likely leftover from debugging.",
     "It is only useful for interactive debugging with trace()"
-  )
+  ),
+  structure =
+    "Use class<-, names<-, and attr<- to set attributes"
 )
 
 #' @rdname default_undesirable_functions
@@ -194,12 +196,14 @@ default_undesirable_functions <- all_undesirable_functions[names(all_undesirable
   "setwd",
   "sink",
   "source",
+  "structure",
   "Sys.setenv",
   "Sys.setlocale",
   "Sys.unsetenv",
   "trace",
   "undebug",
-  "untrace"
+  "untrace",
+  NULL
 )]
 
 #' @rdname default_undesirable_functions
@@ -232,7 +236,8 @@ all_undesirable_operators <- modify_defaults(
 default_undesirable_operators <- all_undesirable_operators[names(all_undesirable_operators) %in% c(
   ":::",
   "<<-",
-  "->>"
+  "->>",
+  NULL
 )]
 
 #' Default lintr settings

tests/testthat/test-checkstyle_output.R

@@ -1,33 +1,31 @@
 test_that("return lint report as checkstyle xml", {
-  lints <- structure(
-    list(
-      Lint(
-        filename = "test_file",
-        line_number = 1L,
-        column_number = 2L,
-        type = "error",
-        line = "a line",
-        message = "foo"
-      ),
-      Lint(
-        filename = "test_file",
-        line_number = 2L,
-        column_number = 1L,
-        type = "style",
-        line = "another line",
-        message = "bar"
-      ),
-      Lint(
-        filename = "test_file2",
-        line_number = 1L,
-        column_number = 1L,
-        type = "warning",
-        line = "yet another line",
-        message = "baz"
-      )
+  lints <- list(
+    Lint(
+      filename = "test_file",
+      line_number = 1L,
+      column_number = 2L,
+      type = "error",
+      line = "a line",
+      message = "foo"
     ),
-    class = "lints"
+    Lint(
+      filename = "test_file",
+      line_number = 2L,
+      column_number = 1L,
+      type = "style",
+      line = "another line",
+      message = "bar"
+    ),
+    Lint(
+      filename = "test_file2",
+      line_number = 1L,
+      column_number = 1L,
+      type = "warning",
+      line = "yet another line",
+      message = "baz"
+    )
   )
+  class(lints) <- "lints"
   tmp <- withr::local_tempfile()
   checkstyle_output(lints, tmp)
 

tests/testthat/test-error.R

@@ -3,12 +3,15 @@ test_that("returns the correct linting", {
   expect_lint('"\\R"', msg_escape_char)
   expect_lint('"\\A"', msg_escape_char)
   expect_lint('"\\z"', msg_escape_char)
+  placeholder_linter <- function(...) NULL
+  class(placeholder_linter) <- "linter"
+  attr(placeholder_linter, "name") <- "null"
   expect_lint(
     "a <- 1
     function() {
     b",
     rex::rex("unexpected end of input"),
-    structure(function(...) NULL, class = "linter", name = "null")
+    placeholder_linter
   )
 
   linter <- equals_na_linter()

tests/testthat/test-methods.R

@@ -50,7 +50,8 @@ test_that("as.data.frame.lints", {
   )
 
   # Convert lints to data.frame
-  lints <- structure(list(l1, l2), class = "lints")
+  lints <- list(l1, l2)
+  class(lints) <- "lints"
   df <- as.data.frame(lints)
   expect_s3_class(df, "data.frame")
 

tests/testthat/test-rstudio_markers.R

@@ -4,19 +4,15 @@ test_that("it returns markers which match lints", {
   mockery::stub(rstudio_source_markers, "rstudioapi::callFun", function(...) list(...))
   mockery::stub(rstudio_source_markers, "rstudioapi::executeCommand", function(...) NULL)
 
-  lint1 <- structure(
-    list(
-      Lint(
-        filename = "test_file",
-        line_number = 1L,
-        column_number = 2L,
-        type = "error",
-        line = "a line",
-        message = "hi"
-      )
-    ),
-    class = "lints"
-  )
+  lint1 <- list(Lint(
+    filename = "test_file",
+    line_number = 1L,
+    column_number = 2L,
+    type = "error",
+    line = "a line",
+    message = "hi"
+  ))
+  class(lint1) <- "lints"
   lint1[[1L]]$linter <- "linter_name"
 
   marker1 <- rstudio_source_markers(lint1)
@@ -27,26 +23,24 @@ test_that("it returns markers which match lints", {
   expect_identical(marker1$markers[[1L]]$column, lint1[[1L]]$column_number)
   expect_identical(marker1$markers[[1L]]$message, paste0("[", lint1[[1L]]$linter, "] ", lint1[[1L]]$message))
 
-  lint2 <- structure(
-    list(
-      Lint(
-        filename = "test_file",
-        line_number = 1L,
-        column_number = 2L,
-        type = "error",
-        line = "a line",
-        message = "hi"
-      ),
-      Lint(
-        filename = "test_file2",
-        line_number = 10L,
-        column_number = 1L,
-        type = "warning",
-        message = "test a message"
-      )
+  lint2 <- list(
+    Lint(
+      filename = "test_file",
+      line_number = 1L,
+      column_number = 2L,
+      type = "error",
+      line = "a line",
+      message = "hi"
     ),
-    class = "lints"
+    Lint(
+      filename = "test_file2",
+      line_number = 10L,
+      column_number = 1L,
+      type = "warning",
+      message = "test a message"
+    )
   )
+  class(lint2) <- "lints"
   lint2[[1L]]$linter <- "linter_name"
   lint2[[2L]]$linter <- "linter_name"
   marker2 <- rstudio_source_markers(lint2)
@@ -64,20 +58,16 @@ test_that("it prepends the package path if it exists", {
   mockery::stub(rstudio_source_markers, "rstudioapi::callFun", function(...) list(...))
   mockery::stub(rstudio_source_markers, "rstudioapi::executeCommand", function(...) NULL)
 
-  lint3 <- structure(
-    list(
-      Lint(
-        filename = "test_file",
-        line_number = 1L,
-        column_number = 2L,
-        type = "error",
-        line = "a line",
-        message = "hi"
-      )
-    ),
-    class = "lints",
-    path = "test"
-  )
+  lint3 <- list(Lint(
+    filename = "test_file",
+    line_number = 1L,
+    column_number = 2L,
+    type = "error",
+    line = "a line",
+    message = "hi"
+  ))
+  class(lint3) <- "lints"
+  attr(lint3, "path") <- "test"
   lint3[[1L]]$linter <- "linter_name"
   marker3 <- rstudio_source_markers(lint3)
   expect_identical(marker3$name, "lintr")
@@ -95,10 +85,7 @@ test_that("it returns an empty list of markers if there are no lints", {
   mockery::stub(rstudio_source_markers, "rstudioapi::callFun", function(...) list(...))
   mockery::stub(rstudio_source_markers, "rstudioapi::executeCommand", function(...) NULL)
 
-  lint4 <- structure(
-    list(),
-    class = "lints"
-  )
+  lint4 <- `class<-`(list(), "lints")
   marker4 <- rstudio_source_markers(lint4)
   expect_identical(marker4$name, "lintr")
   expect_identical(marker4$markers, list())