fix(linter): prevent useConsistentCurlyBraces from producing invalid JSX

Add '{', '<', and '&' to FORBIDDEN_CHARS to prevent the rule from suggesting
to remove curly braces from strings containing characters that cannot appear
unescaped in JSX text, which would produce invalid or semantically different JSX.

Fixes #8011

Author: tt-a1i

.changeset/fix-curly-braces-opening-brace.md

@@ -0,0 +1,5 @@
+---
+"@biomejs/biome": patch
+---
+
+Fixed [#8011](https://github.com/biomejs/biome/issues/8011): [`useConsistentCurlyBraces`](https://biomejs.dev/linter/rules/use-consistent-curly-braces/) no longer suggests removing curly braces from JSX expression children containing characters that would cause parsing issues or semantic changes when converted to plain JSX text (`{`, `}`, `<`, `>`, `&`).

crates/biome_js_analyze/src/lint/style/use_consistent_curly_braces.rs

@@ -410,7 +410,17 @@ fn contains_only_spaces(literal: &JsStringLiteralExpression) -> bool {
         .is_ok_and(|text| text.bytes().all(|b| b == b' '))
 }
 
-const FORBIDDEN_CHARS: [char; 4] = ['>', '"', '\'', '}'];
+/// Characters that would cause parsing issues or semantic changes if a JSX expression
+/// child is converted to plain JSX text. When a string literal contains any of these,
+/// we must NOT suggest removing the curly braces.
+///
+/// - `{` `}` - would be parsed as expression delimiters
+/// - `<` `>` - would be parsed as tag delimiters
+/// - `&` - would be parsed as HTML entity start
+/// - `"` `'` - included for consistency, though mainly relevant in attribute contexts
+///
+/// See: https://github.com/biomejs/biome/issues/8011
+const FORBIDDEN_CHARS: [char; 7] = ['{', '}', '<', '>', '&', '"', '\''];
 
 fn contains_forbidden_chars(str_literal: &JsStringLiteralExpression) -> bool {
     str_literal.inner_string_text().is_ok_and(|text| {

crates/biome_js_analyze/tests/specs/style/useConsistentCurlyBraces/valid.jsx

@@ -28,6 +28,22 @@ let baz = 4;
 
 <Foo>{'Invalid closing tag }'}</Foo>
 
+<Foo>Invalid opening tag {'{'}</Foo>
+
+<Foo>{'Invalid opening tag {'}</Foo>
+
+<Foo>{'start {{'}</Foo>
+
+<Foo>{'}} end'}</Foo>
+
+<Foo>{'<script>'}</Foo>
+
+<Foo>{'a < b'}</Foo>
+
+<Foo>{'&amp;'}</Foo>
+
+<Foo>{'Tom & Jerry'}</Foo>
+
 <Foo>Jupiter {">"} Venus</Foo>
 
 <Foo>Jupiter {'>'} Venus</Foo>

crates/biome_js_analyze/tests/specs/style/useConsistentCurlyBraces/valid.jsx.snap

@@ -34,6 +34,22 @@ let baz = 4;
 
 <Foo>{'Invalid closing tag }'}</Foo>
 
+<Foo>Invalid opening tag {'{'}</Foo>
+
+<Foo>{'Invalid opening tag {'}</Foo>
+
+<Foo>{'start {{'}</Foo>
+
+<Foo>{'}} end'}</Foo>
+
+<Foo>{'<script>'}</Foo>
+
+<Foo>{'a < b'}</Foo>
+
+<Foo>{'&amp;'}</Foo>
+
+<Foo>{'Tom & Jerry'}</Foo>
+
 <Foo>Jupiter {">"} Venus</Foo>
 
 <Foo>Jupiter {'>'} Venus</Foo>