[pycodestyle] Do not ignore lines before the first logical line in blank lines rules (#10382)

## Summary

Ignoring all lines until the first logical line does not match the
behavior from pycodestyle. This PR therefore removes the `if
state.is_not_first_logical_line` skipping the line check before the
first logical line, and applies it only to `E302`.

For example, in the snippet below a rule violation should be detected on
the second comment and on the import.

```python
# first comment




# second comment




import foo
```

Fixes #10374

## Test Plan

Add test cases, update the snapshots and verify the ecosystem check output

Author: hoel-bagard

crates/ruff_linter/resources/test/fixtures/pycodestyle/E302_first_line_docstring.py

@@ -0,0 +1,4 @@
+"""Test where the error is after the module's docstring."""
+
+def fn():
+    pass

crates/ruff_linter/resources/test/fixtures/pycodestyle/E302_first_line_expression.py

@@ -0,0 +1,4 @@
+"Test where the first line is a comment, " + "and the rule violation follows it."
+
+def fn():
+    pass

crates/ruff_linter/resources/test/fixtures/pycodestyle/E302_first_line_function.py

@@ -0,0 +1,5 @@
+def fn1():
+    pass
+
+def fn2():
+    pass

crates/ruff_linter/resources/test/fixtures/pycodestyle/E302_first_line_statement.py

@@ -0,0 +1,4 @@
+print("Test where the first line is a statement, and the rule violation follows it.")
+
+def fn():
+    pass

crates/ruff_linter/resources/test/fixtures/pycodestyle/E303_first_line_comment.py

@@ -0,0 +1,6 @@
+# Test where the first line is a comment, and the rule violation follows it.
+
+
+
+def fn():
+    pass

crates/ruff_linter/resources/test/fixtures/pycodestyle/E303_first_line_docstring.py

@@ -0,0 +1,6 @@
+"""Test where the error is after the module's docstring."""
+
+
+
+def fn():
+    pass

crates/ruff_linter/resources/test/fixtures/pycodestyle/E303_first_line_expression.py

@@ -0,0 +1,6 @@
+"Test where the first line is a comment, " + "and the rule violation follows it."
+
+
+
+def fn():
+    pass

crates/ruff_linter/resources/test/fixtures/pycodestyle/E303_first_line_statement.py

@@ -0,0 +1,6 @@
+print("Test where the first line is a statement, and the rule violation follows it.")
+
+
+
+def fn():
+    pass

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

@@ -171,6 +171,24 @@ mod tests {
         Ok(())
     }
 
+    #[test_case(Rule::BlankLinesTopLevel, Path::new("E302_first_line_docstring.py"))]
+    #[test_case(Rule::BlankLinesTopLevel, Path::new("E302_first_line_expression.py"))]
+    #[test_case(Rule::BlankLinesTopLevel, Path::new("E302_first_line_function.py"))]
+    #[test_case(Rule::BlankLinesTopLevel, Path::new("E302_first_line_statement.py"))]
+    #[test_case(Rule::TooManyBlankLines, Path::new("E303_first_line_comment.py"))]
+    #[test_case(Rule::TooManyBlankLines, Path::new("E303_first_line_docstring.py"))]
+    #[test_case(Rule::TooManyBlankLines, Path::new("E303_first_line_expression.py"))]
+    #[test_case(Rule::TooManyBlankLines, Path::new("E303_first_line_statement.py"))]
+    fn blank_lines_first_line(rule_code: Rule, path: &Path) -> Result<()> {
+        let snapshot = format!("{}_{}", rule_code.noqa_code(), path.to_string_lossy());
+        let diagnostics = test_path(
+            Path::new("pycodestyle").join(path).as_path(),
+            &settings::LinterSettings::for_rule(rule_code),
+        )?;
+        assert_messages!(snapshot, diagnostics);
+        Ok(())
+    }
+
     #[test_case(Rule::BlankLineBetweenMethods, Path::new("E30.py"))]
     #[test_case(Rule::BlankLinesTopLevel, Path::new("E30.py"))]
     #[test_case(Rule::TooManyBlankLines, Path::new("E30.py"))]

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

@@ -696,9 +696,7 @@ impl<'a> BlankLinesChecker<'a> {
             state.class_status.update(&logical_line);
             state.fn_status.update(&logical_line);
 
-            if state.is_not_first_logical_line {
-                self.check_line(&logical_line, &state, prev_indent_length, diagnostics);
-            }
+            self.check_line(&logical_line, &state, prev_indent_length, diagnostics);
 
             match logical_line.kind {
                 LogicalLineKind::Class => {
@@ -818,6 +816,8 @@ impl<'a> BlankLinesChecker<'a> {
             && line.kind.is_class_function_or_decorator()
             // Blank lines in stub files are used to group definitions. Don't enforce blank lines.
             && !self.source_type.is_stub()
+            // Do not expect blank lines before the first logical line.
+            && state.is_not_first_logical_line
         {
             // E302
             let mut diagnostic = Diagnostic::new(

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E302_E302_first_line_docstring.py.snap

@@ -0,0 +1,19 @@
+---
+source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
+---
+E302_first_line_docstring.py:3:1: E302 [*] Expected 2 blank lines, found 1
+  |
+1 | """Test where the error is after the module's docstring."""
+2 | 
+3 | def fn():
+  | ^^^ E302
+4 |     pass
+  |
+  = help: Add missing blank line(s)
+
+ℹ Safe fix
+1 1 | """Test where the error is after the module's docstring."""
+2 2 | 
+  3 |+
+3 4 | def fn():
+4 5 |     pass

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E302_E302_first_line_expression.py.snap

@@ -0,0 +1,19 @@
+---
+source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
+---
+E302_first_line_expression.py:3:1: E302 [*] Expected 2 blank lines, found 1
+  |
+1 | "Test where the first line is a comment, " + "and the rule violation follows it."
+2 | 
+3 | def fn():
+  | ^^^ E302
+4 |     pass
+  |
+  = help: Add missing blank line(s)
+
+ℹ Safe fix
+1 1 | "Test where the first line is a comment, " + "and the rule violation follows it."
+2 2 | 
+  3 |+
+3 4 | def fn():
+4 5 |     pass

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E302_E302_first_line_function.py.snap

@@ -0,0 +1,20 @@
+---
+source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
+---
+E302_first_line_function.py:4:1: E302 [*] Expected 2 blank lines, found 1
+  |
+2 |     pass
+3 | 
+4 | def fn2():
+  | ^^^ E302
+5 |     pass
+  |
+  = help: Add missing blank line(s)
+
+ℹ Safe fix
+1 1 | def fn1():
+2 2 |     pass
+3 3 | 
+  4 |+
+4 5 | def fn2():
+5 6 |     pass

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E302_E302_first_line_statement.py.snap

@@ -0,0 +1,19 @@
+---
+source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
+---
+E302_first_line_statement.py:3:1: E302 [*] Expected 2 blank lines, found 1
+  |
+1 | print("Test where the first line is a statement, and the rule violation follows it.")
+2 | 
+3 | def fn():
+  | ^^^ E302
+4 |     pass
+  |
+  = help: Add missing blank line(s)
+
+ℹ Safe fix
+1 1 | print("Test where the first line is a statement, and the rule violation follows it.")
+2 2 | 
+  3 |+
+3 4 | def fn():
+4 5 |     pass

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E303_E303_first_line_comment.py.snap

@@ -0,0 +1,18 @@
+---
+source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
+---
+E303_first_line_comment.py:5:1: E303 [*] Too many blank lines (3)
+  |
+5 | def fn():
+  | ^^^ E303
+6 |     pass
+  |
+  = help: Remove extraneous blank line(s)
+
+ℹ Safe fix
+1 1 | # Test where the first line is a comment, and the rule violation follows it.
+2 2 | 
+3 3 | 
+4   |-
+5 4 | def fn():
+6 5 |     pass

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E303_E303_first_line_docstring.py.snap

@@ -0,0 +1,18 @@
+---
+source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
+---
+E303_first_line_docstring.py:5:1: E303 [*] Too many blank lines (3)
+  |
+5 | def fn():
+  | ^^^ E303
+6 |     pass
+  |
+  = help: Remove extraneous blank line(s)
+
+ℹ Safe fix
+1 1 | """Test where the error is after the module's docstring."""
+2 2 | 
+3 3 | 
+4   |-
+5 4 | def fn():
+6 5 |     pass

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E303_E303_first_line_expression.py.snap

@@ -0,0 +1,18 @@
+---
+source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
+---
+E303_first_line_expression.py:5:1: E303 [*] Too many blank lines (3)
+  |
+5 | def fn():
+  | ^^^ E303
+6 |     pass
+  |
+  = help: Remove extraneous blank line(s)
+
+ℹ Safe fix
+1 1 | "Test where the first line is a comment, " + "and the rule violation follows it."
+2 2 | 
+3 3 | 
+4   |-
+5 4 | def fn():
+6 5 |     pass

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E303_E303_first_line_statement.py.snap

@@ -0,0 +1,18 @@
+---
+source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
+---
+E303_first_line_statement.py:5:1: E303 [*] Too many blank lines (3)
+  |
+5 | def fn():
+  | ^^^ E303
+6 |     pass
+  |
+  = help: Remove extraneous blank line(s)
+
+ℹ Safe fix
+1 1 | print("Test where the first line is a statement, and the rule violation follows it.")
+2 2 | 
+3 3 | 
+4   |-
+5 4 | def fn():
+6 5 |     pass