Add flynt to documentation (#4295)

LICENSE

@@ -550,6 +550,30 @@ are:
     THE SOFTWARE.
   """
 
+- flynt, licensed as follows:
+  """
+    MIT License
+
+    Copyright (c) 2019-2022 Ilya Kamenshchikov
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+  """
 
 - isort, licensed as follows:
   """

README.md

@@ -281,6 +281,7 @@ quality tools, including:
 - [flake8-tidy-imports](https://pypi.org/project/flake8-tidy-imports/)
 - [flake8-type-checking](https://pypi.org/project/flake8-type-checking/)
 - [flake8-use-pathlib](https://pypi.org/project/flake8-use-pathlib/)
+- [flynt](https://pypi.org/project/flynt/) ([#2102](https://github.com/charliermarsh/ruff/issues/2102))
 - [isort](https://pypi.org/project/isort/)
 - [mccabe](https://pypi.org/project/mccabe/)
 - [pandas-vet](https://pypi.org/project/pandas-vet/)

crates/ruff/src/rules/flynt/helpers.rs

@@ -1,6 +1,7 @@
-use ruff_python_ast::helpers::create_expr;
 use rustpython_parser::ast::{Constant, Expr, ExprKind};
 
+use ruff_python_ast::helpers::create_expr;
+
 /// Wrap an expression in a `FormattedValue` with no special formatting.
 fn to_formatted_value_expr(inner: &Expr) -> Expr {
     create_expr(ExprKind::FormattedValue {

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

@@ -4,12 +4,14 @@ pub(crate) mod rules;
 
 #[cfg(test)]
 mod tests {
+    use std::path::Path;
+
+    use anyhow::Result;
+    use test_case::test_case;
+
     use crate::registry::Rule;
     use crate::test::test_path;
     use crate::{assert_messages, settings};
-    use anyhow::Result;
-    use std::path::Path;
-    use test_case::test_case;
 
     #[test_case(Rule::StaticJoinToFString, Path::new("FLY002.py"); "FLY002")]
     fn rules(rule_code: Rule, path: &Path) -> Result<()> {

crates/ruff/src/rules/flynt/rules/static_join_to_fstring.rs

@@ -1,6 +1,6 @@
 use rustpython_parser::ast::{Expr, ExprKind};
 
-use ruff_diagnostics::{AutofixKind, Diagnostic, Edit, Violation};
+use ruff_diagnostics::{AlwaysAutofixableViolation, Diagnostic, Edit, Fix};
 use ruff_macros::{derive_message_formats, violation};
 use ruff_python_ast::helpers::{create_expr, unparse_expr};
 
@@ -11,21 +11,18 @@ use crate::rules::flynt::helpers;
 #[violation]
 pub struct StaticJoinToFString {
     pub expr: String,
-    pub fixable: bool,
 }
 
-impl Violation for StaticJoinToFString {
-    const AUTOFIX: AutofixKind = AutofixKind::Sometimes;
-
+impl AlwaysAutofixableViolation for StaticJoinToFString {
     #[derive_message_formats]
     fn message(&self) -> String {
-        let StaticJoinToFString { expr, .. } = self;
+        let StaticJoinToFString { expr } = self;
         format!("Consider `{expr}` instead of string join")
     }
 
-    fn autofix_title_formatter(&self) -> Option<fn(&Self) -> String> {
-        self.fixable
-            .then_some(|StaticJoinToFString { expr, .. }| format!("Replace with `{expr}`"))
+    fn autofix_title(&self) -> String {
+        let StaticJoinToFString { expr } = self;
+        format!("Replace with `{expr}`")
     }
 }
 
@@ -44,33 +41,33 @@ fn build_fstring(joiner: &str, joinees: &[Expr]) -> Option<Expr> {
             // gracefully right now.
             return None;
         }
-        if !first {
+        if !std::mem::take(&mut first) {
             fstring_elems.push(helpers::to_constant_string(joiner));
         }
         fstring_elems.push(helpers::to_fstring_elem(expr)?);
-        first = false;
     }
+
     Some(create_expr(ExprKind::JoinedStr {
         values: fstring_elems,
     }))
 }
 
 pub fn static_join_to_fstring(checker: &mut Checker, expr: &Expr, joiner: &str) {
     let ExprKind::Call {
-        func: _,
         args,
         keywords,
+        ..
     } = &expr.node else {
         return;
     };
 
     if !keywords.is_empty() || args.len() != 1 {
-        // If there are kwargs or more than one argument,
-        // this is some non-standard string join call.
+        // If there are kwargs or more than one argument, this is some non-standard
+        // string join call.
         return;
     }
 
-    // Get the elements to join; skip e.g. generators, sets, etc.
+    // Get the elements to join; skip (e.g.) generators, sets, etc.
     let joinees = match &args[0].node {
         ExprKind::List { elts, .. } if is_static_length(elts) => elts,
         ExprKind::Tuple { elts, .. } if is_static_length(elts) => elts,
@@ -86,12 +83,14 @@ pub fn static_join_to_fstring(checker: &mut Checker, expr: &Expr, joiner: &str)
     let mut diagnostic = Diagnostic::new(
         StaticJoinToFString {
             expr: contents.clone(),
-            fixable: true,
         },
         expr.range(),
     );
     if checker.patch(diagnostic.kind.rule()) {
-        diagnostic.set_fix(Edit::range_replacement(contents, expr.range()));
+        diagnostic.set_fix(Fix::unspecified(Edit::range_replacement(
+            contents,
+            expr.range(),
+        )));
     }
     checker.diagnostics.push(diagnostic);
 }

docs/faq.md

@@ -65,6 +65,7 @@ natively, including:
 - [flake8-tidy-imports](https://pypi.org/project/flake8-tidy-imports/)
 - [flake8-type-checking](https://pypi.org/project/flake8-type-checking/)
 - [flake8-use-pathlib](https://pypi.org/project/flake8-use-pathlib/)
+- [flynt](https://pypi.org/project/flynt/) ([#2102](https://github.com/charliermarsh/ruff/issues/2102))
 - [isort](https://pypi.org/project/isort/)
 - [mccabe](https://pypi.org/project/mccabe/)
 - [pandas-vet](https://pypi.org/project/pandas-vet/)
@@ -162,6 +163,7 @@ Today, Ruff can be used to replace Flake8 when used with any of the following pl
 - [flake8-tidy-imports](https://pypi.org/project/flake8-tidy-imports/)
 - [flake8-type-checking](https://pypi.org/project/flake8-type-checking/)
 - [flake8-use-pathlib](https://pypi.org/project/flake8-use-pathlib/)
+- [flynt](https://pypi.org/project/flynt/) ([#2102](https://github.com/charliermarsh/ruff/issues/2102))
 - [mccabe](https://pypi.org/project/mccabe/)
 - [pandas-vet](https://pypi.org/project/pandas-vet/)
 - [pep8-naming](https://pypi.org/project/pep8-naming/)