[ruff] Fix false negative for empty f-strings in deque calls (RUF037) (#20109)

## Summary

Fixes #20050

crates/ruff_linter/resources/test/fixtures/ruff/RUF037.py

@@ -107,3 +107,6 @@ deque(f"{x}" "")  # OK
 deque(t"")
 deque(t""  t"")
 deque(t"{""}") # OK
+
+# https://github.com/astral-sh/ruff/issues/20050
+deque(f"{""}")  # RUF037

crates/ruff_linter/src/rules/ruff/rules/unnecessary_literal_within_deque_call.rs

@@ -1,5 +1,7 @@
 use ruff_diagnostics::{Applicability, Edit};
 use ruff_macros::{ViolationMetadata, derive_message_formats};
+
+use ruff_python_ast::helpers::is_empty_f_string;
 use ruff_python_ast::parenthesize::parenthesized_range;
 use ruff_python_ast::{self as ast, Expr};
 use ruff_text_size::Ranged;
@@ -102,7 +104,7 @@ pub(crate) fn unnecessary_literal_within_deque_call(checker: &Checker, deque: &a
         }
         Expr::StringLiteral(string) => string.value.is_empty(),
         Expr::BytesLiteral(bytes) => bytes.value.is_empty(),
-        Expr::FString(fstring) => fstring.value.is_empty_literal(),
+        Expr::FString(fstring) => is_empty_f_string(fstring),
         Expr::TString(tstring) => tstring.value.is_empty_iterable(),
         _ => false,
     };

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF037_RUF037.py.snap

@@ -369,6 +369,7 @@ help: Replace with `deque()`
 107 + deque()
 108 | deque(t""  t"")
 109 | deque(t"{""}") # OK
+110 | 
 
 RUF037 [*] Unnecessary empty iterable within a deque call
    --> RUF037.py:108:1
@@ -386,3 +387,19 @@ help: Replace with `deque()`
     - deque(t""  t"")
 108 + deque()
 109 | deque(t"{""}") # OK
+110 | 
+111 | # https://github.com/astral-sh/ruff/issues/20050
+
+RUF037 [*] Unnecessary empty iterable within a deque call
+   --> RUF037.py:112:1
+    |
+111 | # https://github.com/astral-sh/ruff/issues/20050
+112 | deque(f"{""}")  # RUF037
+    | ^^^^^^^^^^^^^^
+    |
+help: Replace with `deque()`
+109 | deque(t"{""}") # OK
+110 | 
+111 | # https://github.com/astral-sh/ruff/issues/20050
+    - deque(f"{""}")  # RUF037
+112 + deque()  # RUF037

crates/ruff_python_ast/src/helpers.rs

@@ -1406,7 +1406,7 @@ fn is_non_empty_f_string(expr: &ast::ExprFString) -> bool {
 
 /// Returns `true` if the expression definitely resolves to the empty string, when used as an f-string
 /// expression.
-fn is_empty_f_string(expr: &ast::ExprFString) -> bool {
+pub fn is_empty_f_string(expr: &ast::ExprFString) -> bool {
     fn inner(expr: &Expr) -> bool {
         match expr {
             Expr::StringLiteral(ast::ExprStringLiteral { value, .. }) => value.is_empty(),