Suppress coercion warnings (#2568)

Author: MichaelChirico

NEWS.md

@@ -22,6 +22,7 @@
 * `.lintr` config validation correctly accepts regular expressions which only compile under `perl = TRUE` (#2375, @MichaelChirico). These have always been valid (since `rex::re_matches()`, which powers the lint exclusion logic, also uses this setting), but the new up-front validation in v3.1.1 incorrectly used `perl = FALSE`.
 * `.lintr` configs set by option `lintr.linter_file` or environment variable `R_LINTR_LINTER_FILE` can point to subdirectories (#2512, @MichaelChirico).
 * `indentation_linter()` returns `ranges[1L]==1L` when the offending line has 0 spaces (#2550, @MichaelChirico).
+* `literal_coercion_linter()` doesn't surface a warning about NAs during coercion for code like `as.integer("a")` (#2566, @MichaelChirico).
 
 ## Changes to default linters
 

R/literal_coercion_linter.R

@@ -97,9 +97,14 @@ literal_coercion_linter <- function() {
         needs_prefix <- is_rlang_coercer & !startsWith(coercion_str, "rlang::")
         coercion_str[needs_prefix] <- paste0("rlang::", coercion_str[needs_prefix])
       }
-      # the linter logic & rlang requirement should ensure that it's safe to run eval() here
+      # the linter logic & rlang requirement should ensure that it's safe to run eval() here;
+      #   suppressWarnings() is for cases like 'as.integer("a")' which have an NA result, #2566.
       # TODO(#2473): Avoid a recommendation like '1' that clashes with implicit_integer_linter().
-      literal_equivalent_str <- vapply(str2expression(coercion_str), function(expr) deparse1(eval(expr)), character(1L))
+      literal_equivalent_str <- vapply(
+        str2expression(coercion_str),
+        function(expr) deparse1(suppressWarnings(eval(expr))),
+        character(1L)
+      )
       lint_message <- sprintf(
         "Use %s instead of %s, i.e., use literals directly where possible, instead of coercion.",
         literal_equivalent_str, report_str

tests/testthat/test-literal_coercion_linter.R

@@ -1,5 +1,5 @@
 test_that("literal_coercion_linter skips allowed usages", {
-  linter <- line_length_linter()
+  linter <- literal_coercion_linter()
 
   # naive xpath includes the "_f0" here as a literal
   expect_lint('as.numeric(x$"_f0")', NULL, linter)
@@ -23,7 +23,7 @@ test_that("literal_coercion_linter skips allowed usages", {
 })
 
 test_that("literal_coercion_linter skips allowed rlang usages", {
-  linter <- line_length_linter()
+  linter <- literal_coercion_linter()
 
   expect_lint("int(1, 2.0, 3)", NULL, linter)
   expect_lint("chr('e', 'ab', 'xyz')", NULL, linter)
@@ -40,6 +40,18 @@ test_that("literal_coercion_linter skips quoted keyword arguments", {
   expect_lint("as.numeric(foo('a' = 1))", NULL, literal_coercion_linter())
 })
 
+test_that("no warnings surfaced by running coercion", {
+  linter <- literal_coercion_linter()
+
+  expect_no_warning(
+    expect_lint("as.integer('a')", "Use NA_integer_", linter)
+  )
+
+  expect_no_warning(
+    expect_lint("as.integer(2147483648)", "Use NA_integer_", linter)
+  )
+})
+
 skip_if_not_installed("tibble")
 patrick::with_parameters_test_that(
   "literal_coercion_linter blocks simple disallowed usages",