[pycodestyle] Add blank line(s) rules (E301, E302, E303, `E30…

…4`, `E305`, `E306`) (astral-sh#9266)

Co-authored-by: Micha Reiser <micha@reiser.io>

crates/ruff_linter/src/checkers/logical_lines.rs

@@ -1,3 +1,4 @@
+use crate::line_width::IndentWidth;
 use ruff_diagnostics::Diagnostic;
 use ruff_python_codegen::Stylist;
 use ruff_python_parser::lexer::LexResult;
@@ -15,11 +16,11 @@ use crate::rules::pycodestyle::rules::logical_lines::{
 use crate::settings::LinterSettings;
 
 /// Return the amount of indentation, expanding tabs to the next multiple of the settings' tab size.
-fn expand_indent(line: &str, settings: &LinterSettings) -> usize {
+pub(crate) fn expand_indent(line: &str, indent_width: IndentWidth) -> usize {
     let line = line.trim_end_matches(['\n', '\r']);
 
     let mut indent = 0;
-    let tab_size = settings.tab_size.as_usize();
+    let tab_size = indent_width.as_usize();
     for c in line.bytes() {
         match c {
             b'\t' => indent = (indent / tab_size) * tab_size + tab_size,
@@ -85,7 +86,7 @@ pub(crate) fn check_logical_lines(
             TextRange::new(locator.line_start(first_token.start()), first_token.start())
         };
 
-        let indent_level = expand_indent(locator.slice(range), settings);
+        let indent_level = expand_indent(locator.slice(range), settings.tab_size);
 
         let indent_size = 4;
 

crates/ruff_linter/src/checkers/tokens.rs

@@ -4,6 +4,7 @@ use std::path::Path;
 
 use ruff_notebook::CellOffsets;
 use ruff_python_ast::PySourceType;
+use ruff_python_codegen::Stylist;
 use ruff_python_parser::lexer::LexResult;
 use ruff_python_parser::Tok;
 
@@ -14,24 +15,45 @@ use ruff_source_file::Locator;
 use crate::directives::TodoComment;
 use crate::lex::docstring_detection::StateMachine;
 use crate::registry::{AsRule, Rule};
+use crate::rules::pycodestyle::rules::BlankLinesChecker;
 use crate::rules::ruff::rules::Context;
 use crate::rules::{
     eradicate, flake8_commas, flake8_executable, flake8_fixme, flake8_implicit_str_concat,
     flake8_pyi, flake8_quotes, flake8_todos, pycodestyle, pygrep_hooks, pylint, pyupgrade, ruff,
 };
 use crate::settings::LinterSettings;
 
+#[allow(clippy::too_many_arguments)]
 pub(crate) fn check_tokens(
     tokens: &[LexResult],
     path: &Path,
     locator: &Locator,
     indexer: &Indexer,
+    stylist: &Stylist,
     settings: &LinterSettings,
     source_type: PySourceType,
     cell_offsets: Option<&CellOffsets>,
 ) -> Vec<Diagnostic> {
     let mut diagnostics: Vec<Diagnostic> = vec![];
 
+    if settings.rules.any_enabled(&[
+        Rule::BlankLineBetweenMethods,
+        Rule::BlankLinesTopLevel,
+        Rule::TooManyBlankLines,
+        Rule::BlankLineAfterDecorator,
+        Rule::BlankLinesAfterFunctionOrClass,
+        Rule::BlankLinesBeforeNestedDefinition,
+    ]) {
+        let mut blank_lines_checker = BlankLinesChecker::default();
+        blank_lines_checker.check_lines(
+            tokens,
+            locator,
+            stylist,
+            settings.tab_size,
+            &mut diagnostics,
+        );
+    }
+
     if settings.rules.enabled(Rule::BlanketNOQA) {
         pygrep_hooks::rules::blanket_noqa(&mut diagnostics, indexer, locator);
     }

crates/ruff_linter/src/codes.rs

@@ -137,6 +137,12 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Pycodestyle, "E274") => (RuleGroup::Nursery, rules::pycodestyle::rules::logical_lines::TabBeforeKeyword),
         #[allow(deprecated)]
         (Pycodestyle, "E275") => (RuleGroup::Nursery, rules::pycodestyle::rules::logical_lines::MissingWhitespaceAfterKeyword),
+        (Pycodestyle, "E301") => (RuleGroup::Preview, rules::pycodestyle::rules::BlankLineBetweenMethods),
+        (Pycodestyle, "E302") => (RuleGroup::Preview, rules::pycodestyle::rules::BlankLinesTopLevel),
+        (Pycodestyle, "E303") => (RuleGroup::Preview, rules::pycodestyle::rules::TooManyBlankLines),
+        (Pycodestyle, "E304") => (RuleGroup::Preview, rules::pycodestyle::rules::BlankLineAfterDecorator),
+        (Pycodestyle, "E305") => (RuleGroup::Preview, rules::pycodestyle::rules::BlankLinesAfterFunctionOrClass),
+        (Pycodestyle, "E306") => (RuleGroup::Preview, rules::pycodestyle::rules::BlankLinesBeforeNestedDefinition),
         (Pycodestyle, "E401") => (RuleGroup::Stable, rules::pycodestyle::rules::MultipleImportsOnOneLine),
         (Pycodestyle, "E402") => (RuleGroup::Stable, rules::pycodestyle::rules::ModuleImportNotAtTopOfFile),
         (Pycodestyle, "E501") => (RuleGroup::Stable, rules::pycodestyle::rules::LineTooLong),

crates/ruff_linter/src/linter.rs

@@ -109,6 +109,7 @@ pub fn check_path(
             path,
             locator,
             indexer,
+            stylist,
             settings,
             source_type,
             source_kind.as_ipy_notebook().map(Notebook::cell_offsets),

crates/ruff_linter/src/registry.rs

@@ -264,6 +264,11 @@ impl Rule {
             | Rule::BadQuotesMultilineString
             | Rule::BlanketNOQA
             | Rule::BlanketTypeIgnore
+            | Rule::BlankLineAfterDecorator
+            | Rule::BlankLineBetweenMethods
+            | Rule::BlankLinesAfterFunctionOrClass
+            | Rule::BlankLinesBeforeNestedDefinition
+            | Rule::BlankLinesTopLevel
             | Rule::CommentedOutCode
             | Rule::EmptyComment
             | Rule::ExtraneousParentheses
@@ -296,6 +301,7 @@ impl Rule {
             | Rule::ShebangNotFirstLine
             | Rule::SingleLineImplicitStringConcatenation
             | Rule::TabIndentation
+            | Rule::TooManyBlankLines
             | Rule::TrailingCommaOnBareTuple
             | Rule::TypeCommentInStub
             | Rule::UselessSemicolon

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

@@ -136,6 +136,13 @@ mod tests {
         Path::new("E25.py")
     )]
     #[test_case(Rule::MissingWhitespaceAroundParameterEquals, Path::new("E25.py"))]
+    #[test_case(Rule::BlankLineBetweenMethods, Path::new("E30.py"))]
+    #[test_case(Rule::BlankLinesTopLevel, Path::new("E30.py"))]
+    #[test_case(Rule::TooManyBlankLines, Path::new("E30.py"))]
+    #[test_case(Rule::BlankLineAfterDecorator, Path::new("E30.py"))]
+    #[test_case(Rule::BlankLinesAfterFunctionOrClass, Path::new("E30.py"))]
+    #[test_case(Rule::BlankLinesBeforeNestedDefinition, Path::new("E30.py"))]
+
     fn logical(rule_code: Rule, path: &Path) -> Result<()> {
         let snapshot = format!("{}_{}", rule_code.noqa_code(), path.to_string_lossy());
         let diagnostics = test_path(