Remove special pre-visit for module docstrings (#9261)

This ensures that we visit the module docstring like any other string.

Closes #9260.

crates/ruff_linter/resources/test/fixtures/pycodestyle/E402_1.py

@@ -0,0 +1,9 @@
+import a
+
+"""Some other docstring."""
+
+import b
+
+"""Some other docstring."""
+
+import c

crates/ruff_linter/resources/test/fixtures/pyflakes/F404_1.py

@@ -0,0 +1,5 @@
+"""Docstring"""
+
+"""Non-docstring"""
+
+from __future__ import absolute_import

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP025.py

@@ -1,30 +1,28 @@
-# These should change
-x = u"Hello"
+u"Hello"
 
-u'world'
+x = u"Hello"  # UP025
 
-print(u"Hello")
+u'world'  # UP025
 
-print(u'world')
+print(u"Hello")  # UP025
 
-import foo
-
-foo(u"Hello", U"world", a=u"Hello", b=u"world")
+print(u'world')  # UP025
 
-# These should stay quoted they way they are
+import foo
 
-x = u'hello'
-x = u"""hello"""
-x = u'''hello'''
-x = u'Hello "World"'
+foo(u"Hello", U"world", a=u"Hello", b=u"world")  # UP025
 
-# These should not change
-u = "Hello"
+# Retain quotes when fixing.
+x = u'hello'  # UP025
+x = u"""hello"""  # UP025
+x = u'''hello'''  # UP025
+x = u'Hello "World"'  # UP025
 
-u = u
+u = "Hello"  # OK
+u = u  # OK
 
 def hello():
-    return"Hello"
+    return"Hello"  # OK
 
-f"foo"u"bar"
-f"foo" u"bar"
+f"foo"u"bar"  # OK
+f"foo" u"bar"  # OK

crates/ruff_linter/src/checkers/ast/mod.rs

@@ -287,7 +287,18 @@ where
 
         // Track whether we've seen docstrings, non-imports, etc.
         match stmt {
+            Stmt::Expr(ast::StmtExpr { value, .. })
+                if !self
+                    .semantic
+                    .flags
+                    .intersects(SemanticModelFlags::MODULE_DOCSTRING)
+                    && value.is_string_literal_expr() =>
+            {
+                self.semantic.flags |= SemanticModelFlags::MODULE_DOCSTRING;
+            }
             Stmt::ImportFrom(ast::StmtImportFrom { module, names, .. }) => {
+                self.semantic.flags |= SemanticModelFlags::MODULE_DOCSTRING;
+
                 // Allow __future__ imports until we see a non-__future__ import.
                 if let Some("__future__") = module.as_deref() {
                     if names
@@ -301,9 +312,11 @@ where
                 }
             }
             Stmt::Import(_) => {
+                self.semantic.flags |= SemanticModelFlags::MODULE_DOCSTRING;
                 self.semantic.flags |= SemanticModelFlags::FUTURES_BOUNDARY;
             }
             _ => {
+                self.semantic.flags |= SemanticModelFlags::MODULE_DOCSTRING;
                 self.semantic.flags |= SemanticModelFlags::FUTURES_BOUNDARY;
                 if !(self.semantic.seen_import_boundary()
                     || helpers::is_assignment_to_a_dunder(stmt)
@@ -1435,11 +1448,8 @@ where
 
 impl<'a> Checker<'a> {
     /// Visit a [`Module`]. Returns `true` if the module contains a module-level docstring.
-    fn visit_module(&mut self, python_ast: &'a Suite) -> bool {
+    fn visit_module(&mut self, python_ast: &'a Suite) {
         analyze::module(python_ast, self);
-
-        let docstring = docstrings::extraction::docstring_from(python_ast);
-        docstring.is_some()
     }
 
     /// Visit a list of [`Comprehension`] nodes, assumed to be the comprehensions that compose a
@@ -2006,14 +2016,8 @@ pub(crate) fn check_ast(
     );
     checker.bind_builtins();
 
-    // Check for module docstring.
-    let python_ast = if checker.visit_module(python_ast) {
-        &python_ast[1..]
-    } else {
-        python_ast
-    };
-
     // Iterate over the AST.
+    checker.visit_module(python_ast);
     checker.visit_body(python_ast);
 
     // Visit any deferred syntax nodes. Take care to visit in order, such that we avoid adding

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

@@ -35,7 +35,8 @@ mod tests {
     #[test_case(Rule::LineTooLong, Path::new("E501_3.py"))]
     #[test_case(Rule::MixedSpacesAndTabs, Path::new("E101.py"))]
     #[test_case(Rule::ModuleImportNotAtTopOfFile, Path::new("E40.py"))]
-    #[test_case(Rule::ModuleImportNotAtTopOfFile, Path::new("E402.py"))]
+    #[test_case(Rule::ModuleImportNotAtTopOfFile, Path::new("E402_0.py"))]
+    #[test_case(Rule::ModuleImportNotAtTopOfFile, Path::new("E402_1.py"))]
     #[test_case(Rule::ModuleImportNotAtTopOfFile, Path::new("E402.ipynb"))]
     #[test_case(Rule::MultipleImportsOnOneLine, Path::new("E40.py"))]
     #[test_case(Rule::MultipleStatementsOnOneLineColon, Path::new("E70.py"))]
@@ -65,7 +66,7 @@ mod tests {
     }
 
     #[test_case(Rule::IsLiteral, Path::new("constant_literals.py"))]
-    #[test_case(Rule::ModuleImportNotAtTopOfFile, Path::new("E402.py"))]
+    #[test_case(Rule::ModuleImportNotAtTopOfFile, Path::new("E402_0.py"))]
     #[test_case(Rule::TypeComparison, Path::new("E721.py"))]
     fn preview_rules(rule_code: Rule, path: &Path) -> Result<()> {
         let snapshot = format!(

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E402_E402.py.snap → crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E402_E402_0.py.snap

@@ -1,7 +1,7 @@
 ---
 source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
 ---
-E402.py:25:1: E402 Module level import not at top of file
+E402_0.py:25:1: E402 Module level import not at top of file
    |
 23 | sys.path.insert(0, "some/path")
 24 | 
@@ -11,7 +11,7 @@ E402.py:25:1: E402 Module level import not at top of file
 27 | import matplotlib
    |
 
-E402.py:27:1: E402 Module level import not at top of file
+E402_0.py:27:1: E402 Module level import not at top of file
    |
 25 | import f
 26 | 
@@ -21,7 +21,7 @@ E402.py:27:1: E402 Module level import not at top of file
 29 | matplotlib.use("Agg")
    |
 
-E402.py:31:1: E402 Module level import not at top of file
+E402_0.py:31:1: E402 Module level import not at top of file
    |
 29 | matplotlib.use("Agg")
 30 | 
@@ -31,23 +31,23 @@ E402.py:31:1: E402 Module level import not at top of file
 33 | __some__magic = 1
    |
 
-E402.py:35:1: E402 Module level import not at top of file
+E402_0.py:35:1: E402 Module level import not at top of file
    |
 33 | __some__magic = 1
 34 | 
 35 | import h
    | ^^^^^^^^ E402
    |
 
-E402.py:45:1: E402 Module level import not at top of file
+E402_0.py:45:1: E402 Module level import not at top of file
    |
 43 |     import j
 44 | 
 45 | import k; import l
    | ^^^^^^^^ E402
    |
 
-E402.py:45:11: E402 Module level import not at top of file
+E402_0.py:45:11: E402 Module level import not at top of file
    |
 43 |     import j
 44 | 

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E402_E402_1.py.snap

@@ -0,0 +1,22 @@
+---
+source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
+---
+E402_1.py:5:1: E402 Module level import not at top of file
+  |
+3 | """Some other docstring."""
+4 | 
+5 | import b
+  | ^^^^^^^^ E402
+6 | 
+7 | """Some other docstring."""
+  |
+
+E402_1.py:9:1: E402 Module level import not at top of file
+  |
+7 | """Some other docstring."""
+8 | 
+9 | import c
+  | ^^^^^^^^ E402
+  |
+
+

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__preview__E402_E402.py.snap → crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__preview__E402_E402_0.py.snap

@@ -1,23 +1,23 @@
 ---
 source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
 ---
-E402.py:35:1: E402 Module level import not at top of file
+E402_0.py:35:1: E402 Module level import not at top of file
    |
 33 | __some__magic = 1
 34 | 
 35 | import h
    | ^^^^^^^^ E402
    |
 
-E402.py:45:1: E402 Module level import not at top of file
+E402_0.py:45:1: E402 Module level import not at top of file
    |
 43 |     import j
 44 | 
 45 | import k; import l
    | ^^^^^^^^ E402
    |
 
-E402.py:45:11: E402 Module level import not at top of file
+E402_0.py:45:11: E402 Module level import not at top of file
    |
 43 |     import j
 44 | 

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

@@ -55,7 +55,8 @@ mod tests {
     #[test_case(Rule::UnusedImport, Path::new("F401_20.py"))]
     #[test_case(Rule::ImportShadowedByLoopVar, Path::new("F402.py"))]
     #[test_case(Rule::UndefinedLocalWithImportStar, Path::new("F403.py"))]
-    #[test_case(Rule::LateFutureImport, Path::new("F404.py"))]
+    #[test_case(Rule::LateFutureImport, Path::new("F404_0.py"))]
+    #[test_case(Rule::LateFutureImport, Path::new("F404_1.py"))]
     #[test_case(Rule::UndefinedLocalWithImportStarUsage, Path::new("F405.py"))]
     #[test_case(Rule::UndefinedLocalWithNestedImportStarUsage, Path::new("F406.py"))]
     #[test_case(Rule::FutureFeatureNotDefined, Path::new("F407.py"))]

crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__F404_F404.py.snap → crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__F404_F404_0.py.snap

@@ -1,7 +1,7 @@
 ---
 source: crates/ruff_linter/src/rules/pyflakes/mod.rs
 ---
-F404.py:6:1: F404 `from __future__` imports must occur at the beginning of the file
+F404_0.py:6:1: F404 `from __future__` imports must occur at the beginning of the file
   |
 4 | from collections import namedtuple
 5 | 

crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__F404_F404_1.py.snap

@@ -0,0 +1,12 @@
+---
+source: crates/ruff_linter/src/rules/pyflakes/mod.rs
+---
+F404_1.py:5:1: F404 `from __future__` imports must occur at the beginning of the file
+  |
+3 | """Non-docstring"""
+4 | 
+5 | from __future__ import absolute_import
+  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ F404
+  |
+
+