F401 - Recommend adding unused import bindings to `__all__` (#11314)

Followup on #11168 and resolve #10391

# User facing changes

* F401 now recommends a fix to add unused import bindings to to
`__all__` if a single `__all__` list or tuple is found in `__init__.py`.
* If there are no `__all__` found in the file, fall back to recommending
redundant-aliases.
* If there are multiple `__all__` or only one but of the wrong type (non
list or tuple) then diagnostics are generated without fixes.
* `fix_title` is updated to reflect what the fix/recommendation is.

Subtlety: For a renamed import such as `import foo as bees`, we can
generate a fix to add `bees` to `__all__` but cannot generate a fix to
produce a redundant import (because that would break uses of the binding
`bees`).

# Implementation changes

* Add `name` field to `ImportBinding` to contain the name of the
_binding_ we want to add to `__all__` (important for the `import foo as
bees` case). It previously only contained the `AnyImport` which can give
us information about the import but not the binding.
* Add `binding` field to `UnusedImport` to contain the same. (Naming
note: the field `name` field already existed on `UnusedImport` and
contains the qualified name of the imported symbol/module)
* Change `fix_by_reexporting` to branch on the size of `dunder_all:
Vec<&Expr>`
* For length 0 call the edit-producing function `make_redundant_alias`.
  * For length 1 call edit-producing function `add_to_dunder_all`.
  * Otherwise, produce no fix.
* Implement the edit-producing function `add_to_dunder_all` and add unit
tests.
* Implement several fixture tests: empty `__all__ = []`, nonempty
`__all__ = ["foo"]`, mis-typed `__all__ = None`, plus-eq `__all__ +=
["foo"]`
* `UnusedImportContext::Init` variant now has two fields: whether the
fix is in `__init__.py` and how many `__all__` were found.

# Other changes

* Remove a spurious pattern match and instead use field lookups b/c the
addition of a field would have required changing the unrelated pattern.
* Tweak input type of `make_redundant_alias`

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_25__all_nonempty/__init__.py

@@ -1,4 +1,4 @@
-"""__init__.py with __all__
+"""__init__.py with nonempty __all__
 
 Unused stdlib and third party imports are unsafe removals
 
@@ -33,10 +33,10 @@ from . import aliased as aliased  # Ok: is redundant alias
 from . import exported  # Ok: is exported in __all__
 
 
-# from . import unused # F401: add to __all__
+from . import unused  # F401: add to __all__
 
 
-# from . import renamed as bees # F401: add to __all__
+from . import renamed as bees  # F401: add to __all__
 
 
 __all__ = ["argparse", "exported"]

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_26__all_empty/__init__.py

@@ -0,0 +1,11 @@
+"""__init__.py with empty __all__
+"""
+
+
+from . import unused  # F401: add to __all__
+
+
+from . import renamed as bees  # F401: add to __all__
+
+
+__all__ = []

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_26__all_empty/renamed.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_26__all_empty/unused.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_27__all_mistyped/__init__.py

@@ -0,0 +1,11 @@
+"""__init__.py with mis-typed __all__
+"""
+
+
+from . import unused  # F401: recommend add to all w/o fix
+
+
+from . import renamed as bees  # F401: recommend add to all w/o fix
+
+
+__all__ = None

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_27__all_mistyped/renamed.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_27__all_mistyped/unused.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_28__all_multiple/__init__.py

@@ -0,0 +1,8 @@
+"""__init__.py with multiple imports added to all in one edit
+"""
+
+
+from . import unused, renamed as bees  # F401: add to __all__
+
+
+__all__ = [];

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_28__all_multiple/renamed.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_28__all_multiple/unused.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_29__all_conditional/__init__.py

@@ -0,0 +1,16 @@
+"""__init__.py with __all__ populated by conditional plus-eq
+
+multiple __all__ so cannot offer a fix to add to them
+"""
+
+import sys
+
+from . import unused, exported, renamed as bees
+
+if sys.version_info > (3, 9):
+    from . import also_exported
+
+__all__ = ["exported"]
+
+if sys.version_info >= (3, 9):
+    __all__ += ["also_exported"]

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_29__all_conditional/also_exported.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_29__all_conditional/exported.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_29__all_conditional/renamed.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/resources/test/fixtures/pyflakes/F401_29__all_conditional/unused.py

@@ -0,0 +1 @@
+# empty module imported by __init__.py for test fixture

crates/ruff_linter/src/fix/edits.rs

@@ -1,10 +1,12 @@
 //! Interface for generating fix edits from higher-level actions (e.g., "remove an argument").
 
+use std::borrow::Cow;
+
 use anyhow::{Context, Result};
 
 use ruff_diagnostics::Edit;
 use ruff_python_ast::parenthesize::parenthesized_range;
-use ruff_python_ast::{self as ast, Arguments, ExceptHandler, Stmt};
+use ruff_python_ast::{self as ast, Arguments, ExceptHandler, Expr, ExprList, Stmt};
 use ruff_python_ast::{AnyNodeRef, ArgOrKeyword};
 use ruff_python_codegen::Stylist;
 use ruff_python_index::Indexer;
@@ -124,7 +126,7 @@ pub(crate) fn remove_unused_imports<'a>(
 
 /// Edits to make the specified imports explicit, e.g. change `import x` to `import x as x`.
 pub(crate) fn make_redundant_alias<'a>(
-    member_names: impl Iterator<Item = &'a str>,
+    member_names: impl Iterator<Item = Cow<'a, str>>,
     stmt: &Stmt,
 ) -> Vec<Edit> {
     let aliases = match stmt {
@@ -144,6 +146,53 @@ pub(crate) fn make_redundant_alias<'a>(
         .collect()
 }
 
+/// Fix to add the specified imports to the `__all__` export list.
+pub(crate) fn add_to_dunder_all<'a>(
+    names: impl Iterator<Item = &'a str>,
+    expr: &Expr,
+    stylist: &Stylist,
+) -> Vec<Edit> {
+    let (insertion_point, export_prefix_length) = match expr {
+        Expr::List(ExprList { elts, range, .. }) => (
+            elts.last()
+                .map_or(range.end() - "]".text_len(), Ranged::end),
+            elts.len(),
+        ),
+        Expr::Tuple(tup) if tup.parenthesized => (
+            tup.elts
+                .last()
+                .map_or(tup.end() - ")".text_len(), Ranged::end),
+            tup.elts.len(),
+        ),
+        Expr::Tuple(tup) if !tup.parenthesized => (
+            tup.elts
+                .last()
+                .expect("unparenthesized empty tuple is not possible")
+                .range()
+                .end(),
+            tup.elts.len(),
+        ),
+        _ => {
+            // we don't know how to insert into this expression
+            return vec![];
+        }
+    };
+    let quote = stylist.quote();
+    let mut edits: Vec<_> = names
+        .enumerate()
+        .map(|(offset, name)| match export_prefix_length + offset {
+            0 => Edit::insertion(format!("{quote}{name}{quote}"), insertion_point),
+            _ => Edit::insertion(format!(", {quote}{name}{quote}"), insertion_point),
+        })
+        .collect();
+    if let Expr::Tuple(tup) = expr {
+        if tup.parenthesized && export_prefix_length + edits.len() == 1 {
+            edits.push(Edit::insertion(",".to_string(), insertion_point));
+        }
+    }
+    edits
+}
+
 #[derive(Debug, Copy, Clone)]
 pub(crate) enum Parentheses {
     /// Remove parentheses, if the removed argument is the only argument left.
@@ -477,14 +526,20 @@ fn all_lines_fit(
 
 #[cfg(test)]
 mod tests {
-    use anyhow::Result;
+    use anyhow::{anyhow, Result};
+    use std::borrow::Cow;
+    use test_case::test_case;
 
-    use ruff_diagnostics::Edit;
+    use ruff_diagnostics::{Diagnostic, Edit, Fix};
-    use ruff_python_parser::parse_suite;
+    use ruff_python_codegen::Stylist;
+    use ruff_python_parser::{lexer, parse_expression, parse_suite, Mode};
     use ruff_source_file::Locator;
     use ruff_text_size::{Ranged, TextRange, TextSize};
 
-    use crate::fix::edits::{make_redundant_alias, next_stmt_break, trailing_semicolon};
+    use crate::fix::apply_fixes;
+    use crate::fix::edits::{
+        add_to_dunder_all, make_redundant_alias, next_stmt_break, trailing_semicolon,
+    };
 
     #[test]
     fn find_semicolon() -> Result<()> {
@@ -562,7 +617,7 @@ x = 1 \
         let program = parse_suite(contents).unwrap();
         let stmt = program.first().unwrap();
         assert_eq!(
-            make_redundant_alias(["x"].into_iter(), stmt),
+            make_redundant_alias(["x"].into_iter().map(Cow::from), stmt),
             vec![Edit::range_replacement(
                 String::from("x as x"),
                 TextRange::new(TextSize::new(7), TextSize::new(8)),
@@ -570,7 +625,7 @@ x = 1 \
             "make just one item redundant"
         );
         assert_eq!(
-            make_redundant_alias(vec!["x", "y"].into_iter(), stmt),
+            make_redundant_alias(vec!["x", "y"].into_iter().map(Cow::from), stmt),
             vec![Edit::range_replacement(
                 String::from("x as x"),
                 TextRange::new(TextSize::new(7), TextSize::new(8)),
@@ -578,7 +633,7 @@ x = 1 \
             "the second item is already a redundant alias"
         );
         assert_eq!(
-            make_redundant_alias(vec!["x", "z"].into_iter(), stmt),
+            make_redundant_alias(vec!["x", "z"].into_iter().map(Cow::from), stmt),
             vec![Edit::range_replacement(
                 String::from("x as x"),
                 TextRange::new(TextSize::new(7), TextSize::new(8)),
@@ -586,4 +641,47 @@ x = 1 \
             "the third item is already aliased to something else"
         );
     }
+
+    #[test_case("()",             &["x", "y"], r#"("x", "y")"#             ; "2 into empty tuple")]
+    #[test_case("()",             &["x"],      r#"("x",)"#                 ; "1 into empty tuple adding a trailing comma")]
+    #[test_case("[]",             &["x", "y"], r#"["x", "y"]"#             ; "2 into empty list")]
+    #[test_case("[]",             &["x"],      r#"["x"]"#                  ; "1 into empty list")]
+    #[test_case(r#""a", "b""#,    &["x", "y"], r#""a", "b", "x", "y""#     ; "2 into unparenthesized tuple")]
+    #[test_case(r#""a", "b""#,    &["x"],      r#""a", "b", "x""#          ; "1 into unparenthesized tuple")]
+    #[test_case(r#""a", "b","#,   &["x", "y"], r#""a", "b", "x", "y","#    ; "2 into unparenthesized tuple w/trailing comma")]
+    #[test_case(r#""a", "b","#,   &["x"],      r#""a", "b", "x","#         ; "1 into unparenthesized tuple w/trailing comma")]
+    #[test_case(r#"("a", "b")"#,  &["x", "y"], r#"("a", "b", "x", "y")"#   ; "2 into nonempty tuple")]
+    #[test_case(r#"("a", "b")"#,  &["x"],      r#"("a", "b", "x")"#        ; "1 into nonempty tuple")]
+    #[test_case(r#"("a", "b",)"#, &["x", "y"], r#"("a", "b", "x", "y",)"#  ; "2 into nonempty tuple w/trailing comma")]
+    #[test_case(r#"("a", "b",)"#, &["x"],      r#"("a", "b", "x",)"#       ; "1 into nonempty tuple w/trailing comma")]
+    #[test_case(r#"["a", "b",]"#, &["x", "y"], r#"["a", "b", "x", "y",]"#  ; "2 into nonempty list w/trailing comma")]
+    #[test_case(r#"["a", "b",]"#, &["x"],      r#"["a", "b", "x",]"#       ; "1 into nonempty list w/trailing comma")]
+    #[test_case(r#"["a", "b"]"#,  &["x", "y"], r#"["a", "b", "x", "y"]"#   ; "2 into nonempty list")]
+    #[test_case(r#"["a", "b"]"#,  &["x"],      r#"["a", "b", "x"]"#        ; "1 into nonempty list")]
+    fn add_to_dunder_all_test(raw: &str, names: &[&str], expect: &str) -> Result<()> {
+        let locator = Locator::new(raw);
+        let edits = {
+            let expr = parse_expression(raw)?;
+            let stylist = Stylist::from_tokens(
+                &lexer::lex(raw, Mode::Expression).collect::<Vec<_>>(),
+                &locator,
+            );
+            // SUT
+            add_to_dunder_all(names.iter().copied(), &expr, &stylist)
+        };
+        let diag = {
+            use crate::rules::pycodestyle::rules::MissingNewlineAtEndOfFile;
+            let mut iter = edits.into_iter();
+            Diagnostic::new(
+                MissingNewlineAtEndOfFile, // The choice of rule here is arbitrary.
+                TextRange::default(),
+            )
+            .with_fix(Fix::safe_edits(
+                iter.next().ok_or(anyhow!("expected edits nonempty"))?,
+                iter,
+            ))
+        };
+        assert_eq!(apply_fixes([diag].iter(), &locator).code, expect);
+        Ok(())
+    }
 }

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

@@ -207,7 +207,11 @@ mod tests {
     #[test_case(Rule::UnusedVariable, Path::new("F841_4.py"))]
     #[test_case(Rule::UnusedImport, Path::new("__init__.py"))]
     #[test_case(Rule::UnusedImport, Path::new("F401_24/__init__.py"))]
-    #[test_case(Rule::UnusedImport, Path::new("F401_25__all/__init__.py"))]
+    #[test_case(Rule::UnusedImport, Path::new("F401_25__all_nonempty/__init__.py"))]
+    #[test_case(Rule::UnusedImport, Path::new("F401_26__all_empty/__init__.py"))]
+    #[test_case(Rule::UnusedImport, Path::new("F401_27__all_mistyped/__init__.py"))]
+    #[test_case(Rule::UnusedImport, Path::new("F401_28__all_multiple/__init__.py"))]
+    #[test_case(Rule::UnusedImport, Path::new("F401_29__all_conditional/__init__.py"))]
     fn preview_rules(rule_code: Rule, path: &Path) -> Result<()> {
         let snapshot = format!(
             "preview__{}_{}",

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

@@ -6,8 +6,11 @@ use rustc_hash::FxHashMap;
 
 use ruff_diagnostics::{Applicability, Diagnostic, Fix, FixAvailability, Violation};
 use ruff_macros::{derive_message_formats, violation};
+use ruff_python_ast as ast;
 use ruff_python_ast::{Stmt, StmtImportFrom};
-use ruff_python_semantic::{AnyImport, Exceptions, Imported, NodeId, Scope};
+use ruff_python_semantic::{
+    AnyImport, BindingKind, Exceptions, Imported, NodeId, Scope, SemanticModel,
+};
 use ruff_text_size::{Ranged, TextRange};
 
 use crate::checkers::ast::Checker;
@@ -18,7 +21,10 @@ use crate::rules::{isort, isort::ImportSection, isort::ImportType};
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 enum UnusedImportContext {
     ExceptHandler,
-    Init { first_party: bool },
+    Init {
+        first_party: bool,
+        dunder_all_count: usize,
+    },
 }
 
 /// ## What it does
@@ -79,7 +85,10 @@ enum UnusedImportContext {
 /// - [Typing documentation: interface conventions](https://typing.readthedocs.io/en/latest/source/libraries.html#library-interface-public-and-private-symbols)
 #[violation]
 pub struct UnusedImport {
+    /// Qualified name of the import
     name: String,
+    /// Name of the import binding
+    binding: String,
     context: Option<UnusedImportContext>,
     multiple: bool,
 }
@@ -106,16 +115,31 @@ impl Violation for UnusedImport {
     }
 
     fn fix_title(&self) -> Option<String> {
-        let UnusedImport { name, multiple, .. } = self;
+        let UnusedImport {
-        let resolution = match self.context {
+            name,
-            Some(UnusedImportContext::Init { first_party: true }) => "Use a redundant alias",
+            binding,
-            _ => "Remove unused import",
+            multiple,
-        };
+            ..
-        Some(if *multiple {
+        } = self;
-            resolution.to_string()
+        match self.context {
+            Some(UnusedImportContext::Init {
+                first_party: true,
+                dunder_all_count: 1,
+            }) => Some(format!("Add unused import `{binding}` to __all__")),
+
+            Some(UnusedImportContext::Init {
+                first_party: true,
+                dunder_all_count: 0,
+            }) => Some(format!(
+                "Use an explicit re-export: `{binding} as {binding}`"
+            )),
+
+            _ => Some(if *multiple {
+                "Remove unused import".to_string()
             } else {
-            format!("{resolution}: `{name}`")
+                format!("Remove unused import: `{name}`")
-        })
+            }),
+        }
     }
 }
 
@@ -138,9 +162,32 @@ fn is_first_party(qualified_name: &str, level: u32, checker: &Checker) -> bool {
     }
 }
 
+/// Find the `Expr` for top level `__all__` bindings.
+fn find_dunder_all_exprs<'a>(semantic: &'a SemanticModel) -> Vec<&'a ast::Expr> {
+    semantic
+        .global_scope()
+        .get_all("__all__")
+        .filter_map(|binding_id| {
+            let binding = semantic.binding(binding_id);
+            let stmt = match binding.kind {
+                BindingKind::Export(_) => binding.statement(semantic),
+                _ => None,
+            }?;
+            match stmt {
+                Stmt::Assign(ast::StmtAssign { value, .. }) => Some(&**value),
+                Stmt::AnnAssign(ast::StmtAnnAssign { value, .. }) => value.as_deref(),
+                Stmt::AugAssign(ast::StmtAugAssign { value, .. }) => Some(&**value),
+                _ => None,
+            }
+        })
+        .collect()
+}
+
 /// For some unused binding in an import statement...
 ///
-///  __init__.py ∧ 1stpty → safe,   convert to redundant-alias
+///  __init__.py ∧ 1stpty → safe,   if one __all__, add to __all__
+///                         safe,   if no __all__, convert to redundant-alias
+///                         n/a,    if multiple __all__, offer no fix
 ///  __init__.py ∧ stdlib → unsafe, remove
 ///  __init__.py ∧ 3rdpty → unsafe, remove
 ///
@@ -173,6 +220,7 @@ pub(crate) fn unused_import(checker: &Checker, scope: &Scope, diagnostics: &mut
         };
 
         let import = ImportBinding {
+            name: binding.name(checker.locator()),
             import,
             range: binding.range(),
             parent_range: binding.parent_range(checker.semantic()),
@@ -197,6 +245,7 @@ pub(crate) fn unused_import(checker: &Checker, scope: &Scope, diagnostics: &mut
 
     let in_init = checker.path().ends_with("__init__.py");
     let fix_init = checker.settings.preview.is_enabled();
+    let dunder_all_exprs = find_dunder_all_exprs(checker.semantic());
 
     // Generate a diagnostic for every import, but share fixes across all imports within the same
     // statement (excluding those that are ignored).
@@ -225,6 +274,7 @@ pub(crate) fn unused_import(checker: &Checker, scope: &Scope, diagnostics: &mut
                             level,
                             checker,
                         ),
+                        dunder_all_count: dunder_all_exprs.len(),
                     })
                 } else {
                     None
@@ -234,7 +284,10 @@ pub(crate) fn unused_import(checker: &Checker, scope: &Scope, diagnostics: &mut
             .partition(|(_, context)| {
                 matches!(
                     context,
-                    Some(UnusedImportContext::Init { first_party: true })
+                    Some(UnusedImportContext::Init {
+                        first_party: true,
+                        ..
+                    })
                 )
             });
 
@@ -251,7 +304,8 @@ pub(crate) fn unused_import(checker: &Checker, scope: &Scope, diagnostics: &mut
                 fix_by_reexporting(
                     checker,
                     import_statement,
-                    to_reexport.iter().map(|(binding, _)| binding),
+                    &to_reexport.iter().map(|(b, _)| b).collect::<Vec<_>>(),
+                    &dunder_all_exprs,
                 )
                 .ok(),
             )
@@ -266,6 +320,7 @@ pub(crate) fn unused_import(checker: &Checker, scope: &Scope, diagnostics: &mut
             let mut diagnostic = Diagnostic::new(
                 UnusedImport {
                     name: binding.import.qualified_name().to_string(),
+                    binding: binding.name.to_string(),
                     context,
                     multiple,
                 },
@@ -285,21 +340,17 @@ pub(crate) fn unused_import(checker: &Checker, scope: &Scope, diagnostics: &mut
 
     // Separately, generate a diagnostic for every _ignored_ import, to ensure that the
     // suppression comments aren't marked as unused.
-    for ImportBinding {
+    for binding in ignored.into_values().flatten() {
-        import,
-        range,
-        parent_range,
-    } in ignored.into_values().flatten()
-    {
         let mut diagnostic = Diagnostic::new(
             UnusedImport {
-                name: import.qualified_name().to_string(),
+                name: binding.import.qualified_name().to_string(),
+                binding: binding.name.to_string(),
                 context: None,
                 multiple: false,
             },
-            range,
+            binding.range,
         );
-        if let Some(range) = parent_range {
+        if let Some(range) = binding.parent_range {
             diagnostic.set_parent(range.start());
         }
         diagnostics.push(diagnostic);
@@ -309,6 +360,8 @@ pub(crate) fn unused_import(checker: &Checker, scope: &Scope, diagnostics: &mut
 /// An unused import with its surrounding context.
 #[derive(Debug)]
 struct ImportBinding<'a> {
+    /// Name of the binding, which for renamed imports will differ from the qualified name.
+    name: &'a str,
     /// The qualified name of the import (e.g., `typing.List` for `from typing import List`).
     import: AnyImport<'a, 'a>,
     /// The trimmed range of the import (e.g., `List` in `from typing import List`).
@@ -364,23 +417,31 @@ fn fix_by_removing_imports<'a>(
     )
 }
 
-/// Generate a [`Fix`] to make bindings in a statement explicit, by changing from `import a` to
+/// Generate a [`Fix`] to make bindings in a statement explicit, either by adding them to `__all__`
-/// `import a as a`.
+/// or changing them from `import a` to `import a as a`.
-fn fix_by_reexporting<'a>(
+fn fix_by_reexporting(
     checker: &Checker,
     node_id: NodeId,
-    imports: impl Iterator<Item = &'a ImportBinding<'a>>,
+    imports: &[&ImportBinding],
+    dunder_all_exprs: &[&ast::Expr],
 ) -> Result<Fix> {
     let statement = checker.semantic().statement(node_id);
-
+    if imports.is_empty() {
-    let member_names = imports
-        .map(|binding| binding.import.member_name())
-        .collect::<Vec<_>>();
-    if member_names.is_empty() {
         bail!("Expected import bindings");
     }
 
-    let edits = fix::edits::make_redundant_alias(member_names.iter().map(AsRef::as_ref), statement);
+    let edits = match dunder_all_exprs {
+        [] => fix::edits::make_redundant_alias(
+            imports.iter().map(|b| b.import.member_name()),
+            statement,
+        ),
+        [dunder_all] => fix::edits::add_to_dunder_all(
+            imports.iter().map(|b| b.name),
+            dunder_all,
+            checker.stylist(),
+        ),
+        _ => bail!("Cannot offer a fix when there are multiple __all__ definitions"),
+    };
 
     // Only emit a fix if there are edits
     let mut tail = edits.into_iter();

crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__preview__F401_F401_24____init__.py.snap

@@ -22,7 +22,7 @@ __init__.py:33:15: F401 [*] `.unused` imported but unused; consider removing, ad
 33 | from . import unused  # F401: change to redundant alias
    |               ^^^^^^ F401
    |
-   = help: Use a redundant alias: `.unused`
+   = help: Use an explicit re-export: `unused as unused`
 
 ℹ Safe fix
 30 30 | from . import aliased as aliased  # Ok: is redundant alias
@@ -39,4 +39,4 @@ __init__.py:36:26: F401 `.renamed` imported but unused; consider removing, addin
 36 | from . import renamed as bees  # F401: no fix
    |                          ^^^^ F401
    |
-   = help: Use a redundant alias: `.renamed`
+   = help: Use an explicit re-export: `bees as bees`

crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__preview__F401_F401_25__all____init__.py.snap

@@ -1,18 +0,0 @@
----
-source: crates/ruff_linter/src/rules/pyflakes/mod.rs
----
-__init__.py:19:8: F401 [*] `sys` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
-   |
-19 | import sys  # F401: remove unused
-   |        ^^^ F401
-   |
-   = help: Remove unused import: `sys`
-
-ℹ Unsafe fix
-16 16 | import argparse  # Ok: is exported in __all__
-17 17 | 
-18 18 | 
-19    |-import sys  # F401: remove unused
-20 19 | 
-21 20 | 
-22 21 | # first-party

crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__preview__F401_F401_25__all_nonempty____init__.py.snap

@@ -0,0 +1,46 @@
+---
+source: crates/ruff_linter/src/rules/pyflakes/mod.rs
+---
+__init__.py:19:8: F401 [*] `sys` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+   |
+19 | import sys  # F401: remove unused
+   |        ^^^ F401
+   |
+   = help: Remove unused import: `sys`
+
+ℹ Unsafe fix
+16 16 | import argparse  # Ok: is exported in __all__
+17 17 | 
+18 18 | 
+19    |-import sys  # F401: remove unused
+20 19 | 
+21 20 | 
+22 21 | # first-party
+
+__init__.py:36:15: F401 [*] `.unused` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+   |
+36 | from . import unused  # F401: add to __all__
+   |               ^^^^^^ F401
+   |
+   = help: Add unused import `unused` to __all__
+
+ℹ Safe fix
+39 39 | from . import renamed as bees  # F401: add to __all__
+40 40 | 
+41 41 | 
+42    |-__all__ = ["argparse", "exported"]
+   42 |+__all__ = ["argparse", "exported", "unused"]
+
+__init__.py:39:26: F401 [*] `.renamed` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+   |
+39 | from . import renamed as bees  # F401: add to __all__
+   |                          ^^^^ F401
+   |
+   = help: Add unused import `bees` to __all__
+
+ℹ Safe fix
+39 39 | from . import renamed as bees  # F401: add to __all__
+40 40 | 
+41 41 | 
+42    |-__all__ = ["argparse", "exported"]
+   42 |+__all__ = ["argparse", "exported", "bees"]

crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__preview__F401_F401_26__all_empty____init__.py.snap

@@ -0,0 +1,30 @@
+---
+source: crates/ruff_linter/src/rules/pyflakes/mod.rs
+---
+__init__.py:5:15: F401 [*] `.unused` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+  |
+5 | from . import unused  # F401: add to __all__
+  |               ^^^^^^ F401
+  |
+  = help: Add unused import `unused` to __all__
+
+ℹ Safe fix
+8  8  | from . import renamed as bees  # F401: add to __all__
+9  9  | 
+10 10 | 
+11    |-__all__ = []
+   11 |+__all__ = ["unused"]
+
+__init__.py:8:26: F401 [*] `.renamed` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+  |
+8 | from . import renamed as bees  # F401: add to __all__
+  |                          ^^^^ F401
+  |
+  = help: Add unused import `bees` to __all__
+
+ℹ Safe fix
+8  8  | from . import renamed as bees  # F401: add to __all__
+9  9  | 
+10 10 | 
+11    |-__all__ = []
+   11 |+__all__ = ["bees"]

crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__preview__F401_F401_27__all_mistyped____init__.py.snap

@@ -0,0 +1,16 @@
+---
+source: crates/ruff_linter/src/rules/pyflakes/mod.rs
+---
+__init__.py:5:15: F401 `.unused` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+  |
+5 | from . import unused  # F401: recommend add to all w/o fix
+  |               ^^^^^^ F401
+  |
+  = help: Add unused import `unused` to __all__
+
+__init__.py:8:26: F401 `.renamed` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+  |
+8 | from . import renamed as bees  # F401: recommend add to all w/o fix
+  |                          ^^^^ F401
+  |
+  = help: Add unused import `bees` to __all__

crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__preview__F401_F401_28__all_multiple____init__.py.snap

@@ -0,0 +1,30 @@
+---
+source: crates/ruff_linter/src/rules/pyflakes/mod.rs
+---
+__init__.py:5:15: F401 [*] `.unused` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+  |
+5 | from . import unused, renamed as bees  # F401: add to __all__
+  |               ^^^^^^ F401
+  |
+  = help: Add unused import `unused` to __all__
+
+ℹ Safe fix
+5 5 | from . import unused, renamed as bees  # F401: add to __all__
+6 6 | 
+7 7 | 
+8   |-__all__ = [];
+  8 |+__all__ = ["bees", "unused"];
+
+__init__.py:5:34: F401 [*] `.renamed` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+  |
+5 | from . import unused, renamed as bees  # F401: add to __all__
+  |                                  ^^^^ F401
+  |
+  = help: Add unused import `bees` to __all__
+
+ℹ Safe fix
+5 5 | from . import unused, renamed as bees  # F401: add to __all__
+6 6 | 
+7 7 | 
+8   |-__all__ = [];
+  8 |+__all__ = ["bees", "unused"];

crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__preview__F401_F401_29__all_conditional____init__.py.snap

@@ -0,0 +1,24 @@
+---
+source: crates/ruff_linter/src/rules/pyflakes/mod.rs
+---
+__init__.py:8:15: F401 `.unused` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+   |
+ 6 | import sys
+ 7 | 
+ 8 | from . import unused, exported, renamed as bees
+   |               ^^^^^^ F401
+ 9 | 
+10 | if sys.version_info > (3, 9):
+   |
+   = help: Remove unused import
+
+__init__.py:8:44: F401 `.renamed` imported but unused; consider removing, adding to `__all__`, or using a redundant alias
+   |
+ 6 | import sys
+ 7 | 
+ 8 | from . import unused, exported, renamed as bees
+   |                                            ^^^^ F401
+ 9 | 
+10 | if sys.version_info > (3, 9):
+   |
+   = help: Remove unused import