Move the cyclocomp namespace check into the factory (#2785)

Author: MichaelChirico

R/cyclocomp_linter.R

@@ -22,16 +22,16 @@
 #' @seealso [linters] for a complete list of linters available in lintr.
 #' @export
 cyclocomp_linter <- function(complexity_limit = 15L) {
+  # nocov start
+  if (!requireNamespace("cyclocomp", quietly = TRUE)) {
+    cli::cli_warn(c(
+      "Cyclocomp complexity is computed using {.fn cyclocomp::cyclocomp}.",
+      i = "Please install the needed {.pkg cyclocomp} package."
+    ))
+    return(Linter(function(.) cli_abort("cyclocomp_linter is disabled due to lack of the {.pkg cyclocomp} package")))
+  }
+  # nocov end
   Linter(linter_level = "expression", function(source_expression) {
-    # nocov start
-    if (!requireNamespace("cyclocomp", quietly = TRUE)) {
-      cli::cli_abort(c(
-        "Cyclocomp complexity is computed using {.fn cyclocomp::cyclocomp}.",
-        i = "Please install the needed {.pkg cyclocomp} package."
-      ))
-    }
-    # nocov end
-
     complexity <- try_silently(
       cyclocomp::cyclocomp(parse(text = source_expression$content))
     )

R/settings.R

@@ -157,7 +157,7 @@ read_config_file <- function(config_file, call = parent.frame()) {
       error = malformed
     ),
     warning = function(w) {
-      cli::cli_warn(
+      cli_warn(
         "Warning encountered while loading config:",
         parent = w
       )

tests/testthat/test-cyclocomp_linter.R

@@ -59,3 +59,15 @@ test_that("returns the correct linting", {
     cyclocomp_linter(5L)
   )
 })
+
+test_that("a null linter is returned, with warning, if cyclocomp is unavailable", {
+  # simple requireNamspace->FALSE won't work since expect_no_lint checks for testthat
+  local_mocked_bindings(
+    requireNamespace = function(pkg, ...) pkg != "cyclocomp" && base::requireNamespace(pkg, ...)
+  )
+  expect_warning(regexp = "Please install", fixed = TRUE, {
+    linter <- cyclocomp_linter(1L)
+  })
+
+  expect_error(lint(text = "if (TRUE) 1 else 2", linters = linter), "disabled", fixed = TRUE)
+})

tests/testthat/test-get_source_expressions.R

@@ -104,6 +104,7 @@ test_that("Multi-byte character truncated by parser is ignored", {
 })
 
 test_that("Can read non UTF-8 file", {
+  withr::local_options(lintr.linter_file = tempfile())
   file <- test_path("dummy_projects", "project", "cp1252.R")
   lintr:::read_settings(file)
   expect_null(get_source_expressions(file)$error)

tests/testthat/test-linter_tags.R

@@ -53,6 +53,8 @@ test_that("default_linters and default tag match up", {
 })
 
 test_that("warnings occur only for deprecated linters", {
+  skip_if_not_installed("cyclocomp") # actually we expect a warning there
+
   expect_silent(linters_with_tags(tags = NULL))
   num_deprecated_linters <- nrow(available_linters(tags = "deprecated", exclude_tags = NULL))
   deprecation_warns_seen <- 0L

tests/testthat/test-settings.R

@@ -106,6 +106,8 @@ test_that("linters_with_defaults doesn't break on very long input", {
 })
 
 test_that("it has a smart default for encodings", {
+  withr::local_options(list(lintr.linter_file = tempfile()))
+
   lintr:::read_settings(NULL)
   expect_identical(settings$encoding, "UTF-8")
 

tests/testthat/test-use_lintr.R

@@ -32,6 +32,7 @@ test_that("use_lintr with type = full also works", {
     file.path(normalize_path(tmp), ".lintr")
   )
 
+  skip_if_not_installed("cyclocomp") # avoid warning
   lints <- lint_dir(tmp)
   expect_length(lints, 0L)
 })

tests/testthat/test-with.R

@@ -64,6 +64,8 @@ test_that("all default linters are tagged default", {
 })
 
 test_that("can instantiate all linters without arguments", {
+  skip_if_not_installed("cyclocomp") # avoid warning
+
   all_linters <- linters_with_tags(tags = NULL)
 
   expect_type(all_linters, "list")
@@ -100,13 +102,17 @@ test_that("linters_with_defaults(default = .) is supported with a deprecation wa
 })
 
 test_that("all_linters contains all available linters", {
+  skip_if_not_installed("cyclocomp") # avoid warning
+
   all_linters <- all_linters(packages = "lintr")
 
   expect_identical(linters_with_tags(NULL, packages = "lintr"), all_linters)
   expect_length(all_linters, nrow(available_linters()))
 })
 
 test_that("all_linters respects ellipsis argument", {
+  skip_if_not_installed("cyclocomp") # avoid warning
+
   expect_identical(
     linters_with_tags(tags = NULL, implicit_integer_linter = NULL),
     all_linters(packages = "lintr", implicit_integer_linter = NULL)