[flake8-errmsg] Stabilize extending raw-string-in-exception (EM101) to support byte strings (#20273)

Introduced in #18867. Removed gating, updated tests, updated docs.

Author: dylwil3

crates/ruff_linter/src/preview.rs

@@ -200,11 +200,6 @@ pub(crate) const fn is_optional_as_none_in_union_enabled(settings: &LinterSettin
     settings.preview.is_enabled()
 }
 
-// https://github.com/astral-sh/ruff/pull/18867
-pub(crate) const fn is_raise_exception_byte_string_enabled(settings: &LinterSettings) -> bool {
-    settings.preview.is_enabled()
-}
-
 // https://github.com/astral-sh/ruff/pull/18683
 pub(crate) const fn is_safe_super_call_with_parameters_fix_enabled(
     settings: &LinterSettings,

crates/ruff_linter/src/rules/flake8_errmsg/mod.rs

@@ -9,7 +9,6 @@ mod tests {
     use anyhow::Result;
 
     use crate::registry::Rule;
-    use crate::settings::types::PreviewMode;
     use crate::test::test_path;
     use crate::{assert_diagnostics, settings};
 
@@ -47,15 +46,14 @@ mod tests {
     }
 
     #[test]
-    fn preview_string_exception() -> Result<()> {
+    fn string_exception() -> Result<()> {
         let diagnostics = test_path(
             Path::new("flake8_errmsg/EM101_byte_string.py"),
             &settings::LinterSettings {
-                preview: PreviewMode::Enabled,
                 ..settings::LinterSettings::for_rule(Rule::RawStringInException)
             },
         )?;
-        assert_diagnostics!("preview", diagnostics);
+        assert_diagnostics!(diagnostics);
         Ok(())
     }
 }

crates/ruff_linter/src/rules/flake8_errmsg/rules/string_in_exception.rs

@@ -7,16 +7,12 @@ use ruff_text_size::Ranged;
 
 use crate::Locator;
 use crate::checkers::ast::Checker;
-use crate::preview::is_raise_exception_byte_string_enabled;
 use crate::registry::Rule;
 use crate::{Edit, Fix, FixAvailability, Violation};
 
 /// ## What it does
 /// Checks for the use of string literals in exception constructors.
 ///
-/// In [preview], this rule checks for byte string literals in
-/// exception constructors.
-///
 /// ## Why is this bad?
 /// Python includes the `raise` in the default traceback (and formatters
 /// like Rich and IPython do too).
@@ -51,8 +47,6 @@ use crate::{Edit, Fix, FixAvailability, Violation};
 ///     raise RuntimeError(msg)
 /// RuntimeError: 'Some value' is incorrect
 /// ```
-///
-/// [preview]: https://docs.astral.sh/ruff/preview/
 #[derive(ViolationMetadata)]
 pub(crate) struct RawStringInException;
 
@@ -218,9 +212,7 @@ pub(crate) fn string_in_exception(checker: &Checker, stmt: &Stmt, exc: &Expr) {
             // Check for byte string literals.
             Expr::BytesLiteral(ast::ExprBytesLiteral { value: bytes, .. }) => {
                 if checker.settings().rules.enabled(Rule::RawStringInException) {
-                    if bytes.len() >= checker.settings().flake8_errmsg.max_string_length
-                        && is_raise_exception_byte_string_enabled(checker.settings())
-                    {
+                    if bytes.len() >= checker.settings().flake8_errmsg.max_string_length {
                         let mut diagnostic =
                             checker.report_diagnostic(RawStringInException, first.range());
                         if let Some(indentation) = whitespace::indentation(checker.source(), stmt) {