Remove multiple-statements-on-one-line-def (E704) (#2773)

BREAKING_CHANGES.md

@@ -1,5 +1,12 @@
 # Breaking Changes
 
+## 0.0.246
+
+### `multiple-statements-on-one-line-def` (`E704`) was removed ([#2773](https://github.com/charliermarsh/ruff/pull/2773))
+
+This rule was introduced in v0.0.245. However, it turns out that pycodestyle and Flake8 ignore this
+rule by default, as it is not part of PEP 8. As such, we've removed it from Ruff.
+
 ## 0.0.245
 
 ### Ruff's public `check` method was removed ([#2709](https://github.com/charliermarsh/ruff/pull/2709))

crates/ruff/src/checkers/tokens.rs

@@ -40,10 +40,7 @@ pub fn check_tokens(
         || settings
             .rules
             .enabled(&Rule::MultipleStatementsOnOneLineSemicolon)
-        || settings.rules.enabled(&Rule::UselessSemicolon)
-        || settings
-            .rules
-            .enabled(&Rule::MultipleStatementsOnOneLineDef);
+        || settings.rules.enabled(&Rule::UselessSemicolon);
     let enforce_invalid_escape_sequence = settings.rules.enabled(&Rule::InvalidEscapeSequence);
     let enforce_implicit_string_concatenation = settings
         .rules
@@ -117,7 +114,7 @@ pub fn check_tokens(
         }
     }
 
-    // E701, E702, E703, E704
+    // E701, E702, E703
     if enforce_compound_statements {
         diagnostics.extend(
             pycodestyle::rules::compound_statements(tokens)

crates/ruff/src/flake8_to_ruff/parser.rs

@@ -282,10 +282,6 @@ mod tests {
                 pattern: "examples/*".to_string(),
                 prefix: RuleCodePrefix::F841.into(),
             },
-            PatternPrefixPair {
-                pattern: "*.pyi".to_string(),
-                prefix: RuleCodePrefix::E704.into(),
-            },
         ];
         assert_eq!(actual, expected);
 

crates/ruff/src/registry.rs

@@ -63,7 +63,6 @@ ruff_macros::define_rule_mapping!(
     E701 => rules::pycodestyle::rules::MultipleStatementsOnOneLineColon,
     E702 => rules::pycodestyle::rules::MultipleStatementsOnOneLineSemicolon,
     E703 => rules::pycodestyle::rules::UselessSemicolon,
-    E704 => rules::pycodestyle::rules::MultipleStatementsOnOneLineDef,
     E711 => rules::pycodestyle::rules::NoneComparison,
     E712 => rules::pycodestyle::rules::TrueFalseComparison,
     E713 => rules::pycodestyle::rules::NotInTest,
@@ -774,7 +773,6 @@ impl Rule {
             | Rule::TrailingCommaOnBareTupleProhibited
             | Rule::MultipleStatementsOnOneLineColon
             | Rule::UselessSemicolon
-            | Rule::MultipleStatementsOnOneLineDef
             | Rule::MultipleStatementsOnOneLineSemicolon
             | Rule::TrailingCommaProhibited => &LintSource::Tokens,
             Rule::IOError => &LintSource::Io,

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

@@ -30,7 +30,6 @@ mod tests {
     #[test_case(Rule::ModuleImportNotAtTopOfFile, Path::new("E402.py"))]
     #[test_case(Rule::MultipleImportsOnOneLine, Path::new("E40.py"))]
     #[test_case(Rule::MultipleStatementsOnOneLineColon, Path::new("E70.py"))]
-    #[test_case(Rule::MultipleStatementsOnOneLineDef, Path::new("E70.py"))]
     #[test_case(Rule::MultipleStatementsOnOneLineSemicolon, Path::new("E70.py"))]
     #[test_case(Rule::NoNewLineAtEndOfFile, Path::new("W292_0.py"))]
     #[test_case(Rule::NoNewLineAtEndOfFile, Path::new("W292_1.py"))]

crates/ruff/src/rules/pycodestyle/rules/compound_statements.rs

@@ -36,21 +36,10 @@ impl Violation for UselessSemicolon {
     }
 }
 
-define_violation!(
-    pub struct MultipleStatementsOnOneLineDef;
-);
-impl Violation for MultipleStatementsOnOneLineDef {
-    #[derive_message_formats]
-    fn message(&self) -> String {
-        format!("Multiple statements on one line (def)")
-    }
-}
-
 pub fn compound_statements(lxr: &[LexResult]) -> Vec<Diagnostic> {
     let mut diagnostics = vec![];
 
     // Track the last seen instance of a variety of tokens.
-    let mut def = None;
     let mut colon = None;
     let mut semi = None;
     let mut class = None;
@@ -103,7 +92,6 @@ pub fn compound_statements(lxr: &[LexResult]) -> Vec<Diagnostic> {
                 }
 
                 // Reset.
-                def = None;
                 colon = None;
                 semi = None;
                 class = None;
@@ -117,12 +105,8 @@ pub fn compound_statements(lxr: &[LexResult]) -> Vec<Diagnostic> {
                 while_ = None;
                 with = None;
             }
-            Tok::Def => {
-                def = Some((start, end));
-            }
             Tok::Colon => {
-                if def.is_some()
-                    || class.is_some()
+                if class.is_some()
                     || elif.is_some()
                     || else_.is_some()
                     || except.is_some()
@@ -152,20 +136,12 @@ pub fn compound_statements(lxr: &[LexResult]) -> Vec<Diagnostic> {
                 }
 
                 if let Some((start, end)) = colon {
-                    if let Some((start, end)) = def {
-                        diagnostics.push(Diagnostic::new(
-                            MultipleStatementsOnOneLineDef,
-                            Range::new(start, end),
-                        ));
-                    } else {
-                        diagnostics.push(Diagnostic::new(
-                            MultipleStatementsOnOneLineColon,
-                            Range::new(start, end),
-                        ));
-                    }
+                    diagnostics.push(Diagnostic::new(
+                        MultipleStatementsOnOneLineColon,
+                        Range::new(start, end),
+                    ));
 
                     // Reset.
-                    def = None;
                     colon = None;
                     class = None;
                     elif = None;
@@ -184,7 +160,6 @@ pub fn compound_statements(lxr: &[LexResult]) -> Vec<Diagnostic> {
         match tok {
             Tok::Lambda => {
                 // Reset.
-                def = None;
                 colon = None;
                 class = None;
                 elif = None;

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

@@ -3,8 +3,8 @@ pub use ambiguous_function_name::{ambiguous_function_name, AmbiguousFunctionName
 pub use ambiguous_variable_name::{ambiguous_variable_name, AmbiguousVariableName};
 pub use bare_except::{bare_except, BareExcept};
 pub use compound_statements::{
-    compound_statements, MultipleStatementsOnOneLineColon, MultipleStatementsOnOneLineDef,
-    MultipleStatementsOnOneLineSemicolon, UselessSemicolon,
+    compound_statements, MultipleStatementsOnOneLineColon, MultipleStatementsOnOneLineSemicolon,
+    UselessSemicolon,
 };
 pub use doc_line_too_long::{doc_line_too_long, DocLineTooLong};
 pub use errors::{syntax_error, IOError, SyntaxError};