wip

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

@@ -1,5 +1,5 @@
 use ruff_text_size::TextRange;
-use rustpython_parser::ast::{self, Expr, Ranged};
+use rustpython_parser::ast::{self, Constant, Expr, Ranged};
 
 use ruff_diagnostics::{AlwaysAutofixableViolation, Diagnostic, Edit, Fix};
 use ruff_macros::{derive_message_formats, violation};
@@ -33,6 +33,7 @@ fn is_static_length(elts: &[Expr]) -> bool {
 fn build_fstring(joiner: &str, joinees: &[Expr]) -> Option<Expr> {
     let mut fstring_elems = Vec::with_capacity(joinees.len() * 2);
     let mut first = true;
+    let mut only_strings = true;
 
     for expr in joinees {
         if matches!(expr, Expr::JoinedStr(_)) {
@@ -44,11 +45,29 @@ fn build_fstring(joiner: &str, joinees: &[Expr]) -> Option<Expr> {
             fstring_elems.push(helpers::to_constant_string(joiner));
         }
         fstring_elems.push(helpers::to_fstring_elem(expr)?);
+
+        if !matches!(
+            expr,
+            Expr::Constant(ast::ExprConstant {
+                value: Constant::Str(_),
+                ..
+            })
+        ) {
+            only_strings = false;
+        }
     }
 
-    let node = ast::ExprJoinedStr {
-        values: fstring_elems,
-        range: TextRange::default(),
+    let node = if only_strings {
+        ast::Expr::Constant(ast::ExprConstant {
+            value: fstring_elems.iter().collect::<String>().into(),
+            range: TextRange::default(),
+            kind: None,
+        })
+    } else {
+        ast::ExprJoinedStr {
+            values: fstring_elems,
+            range: TextRange::default(),
+        }
     };
     Some(node.into())
 }
@@ -58,7 +77,7 @@ pub(crate) fn static_join_to_fstring(checker: &mut Checker, expr: &Expr, joiner:
         args,
         keywords,
         ..
-    })= expr else {
+    }) = expr else {
         return;
     };