[ruff] Stabilize checking for file-level directives in unused-noqa (RUF100) (#18497)

Note that the preview behavior was not documented (shame on us!) so the
documentation was not modified.

---------

Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>

Author: dylwil3

crates/ruff_linter/src/checkers/noqa.rs

@@ -12,7 +12,6 @@ use crate::fix::edits::delete_comment;
 use crate::noqa::{
     Code, Directive, FileExemption, FileNoqaDirectives, NoqaDirectives, NoqaMapping,
 };
-use crate::preview::is_check_file_level_directives_enabled;
 use crate::registry::{AsRule, Rule, RuleSet};
 use crate::rule_redirects::get_redirect_target;
 use crate::rules::pygrep_hooks;
@@ -112,25 +111,16 @@ pub(crate) fn check_noqa(
         && !exemption.includes(Rule::UnusedNOQA)
         && !per_file_ignores.contains(Rule::UnusedNOQA)
     {
-        let directives: Vec<_> = if is_check_file_level_directives_enabled(settings) {
-            noqa_directives
-                .lines()
-                .iter()
-                .map(|line| (&line.directive, &line.matches, false))
-                .chain(
-                    file_noqa_directives
-                        .lines()
-                        .iter()
-                        .map(|line| (&line.parsed_file_exemption, &line.matches, true)),
-                )
-                .collect()
-        } else {
-            noqa_directives
-                .lines()
-                .iter()
-                .map(|line| (&line.directive, &line.matches, false))
-                .collect()
-        };
+        let directives = noqa_directives
+            .lines()
+            .iter()
+            .map(|line| (&line.directive, &line.matches, false))
+            .chain(
+                file_noqa_directives
+                    .lines()
+                    .iter()
+                    .map(|line| (&line.parsed_file_exemption, &line.matches, true)),
+            );
         for (directive, matches, is_file_level) in directives {
             match directive {
                 Directive::All(directive) => {

crates/ruff_linter/src/preview.rs

@@ -109,11 +109,6 @@ pub(crate) const fn is_allow_nested_roots_enabled(settings: &LinterSettings) ->
     settings.preview.is_enabled()
 }
 
-// https://github.com/astral-sh/ruff/pull/17061
-pub(crate) const fn is_check_file_level_directives_enabled(settings: &LinterSettings) -> bool {
-    settings.preview.is_enabled()
-}
-
 // https://github.com/astral-sh/ruff/pull/18208
 pub(crate) const fn is_multiple_with_statements_fix_safe_enabled(
     settings: &LinterSettings,

crates/ruff_linter/src/rules/ruff/mod.rs

@@ -324,10 +324,7 @@ mod tests {
     fn ruff_noqa_filedirective_unused() -> Result<()> {
         let diagnostics = test_path(
             Path::new("ruff/RUF100_6.py"),
-            &settings::LinterSettings {
-                preview: PreviewMode::Enabled,
-                ..settings::LinterSettings::for_rules(vec![Rule::UnusedNOQA])
-            },
+            &settings::LinterSettings::for_rules(vec![Rule::UnusedNOQA]),
         )?;
         assert_messages!(diagnostics);
         Ok(())
@@ -337,15 +334,12 @@ mod tests {
     fn ruff_noqa_filedirective_unused_last_of_many() -> Result<()> {
         let diagnostics = test_path(
             Path::new("ruff/RUF100_7.py"),
-            &settings::LinterSettings {
-                preview: PreviewMode::Enabled,
-                ..settings::LinterSettings::for_rules(vec![
-                    Rule::UnusedNOQA,
-                    Rule::FStringMissingPlaceholders,
-                    Rule::LineTooLong,
-                    Rule::UnusedVariable,
-                ])
-            },
+            &settings::LinterSettings::for_rules(vec![
+                Rule::UnusedNOQA,
+                Rule::FStringMissingPlaceholders,
+                Rule::LineTooLong,
+                Rule::UnusedVariable,
+            ]),
         )?;
         assert_messages!(diagnostics);
         Ok(())