fix(lint): skip noUselessStringConcat for tagged templates

.changeset/pretty-hornets-rescue.md

@@ -0,0 +1,5 @@
+---
+"@biomejs/biome": patch
+---
+
+Fixed [#9505](https://github.com/biomejs/biome/issues/9505): [`noUselessStringConcat`](https://biomejs.dev/linter/rules/no-useless-string-concat/) no longer reports tagged template literals as useless string concatenations. Tagged templates invoke a function and can return non-string values, so combining them with `+` is not equivalent to a single template literal.

crates/biome_js_analyze/src/lint/complexity/no_useless_string_concat.rs

@@ -227,7 +227,7 @@ fn is_string_expression(expression: &Option<AnyJsExpression>) -> bool {
             (Some(literal_expression), _) => literal_expression
                 .as_js_string_literal_expression()
                 .is_some(),
-            (_, Some(_template_expression)) => true,
+            (_, Some(template_expression)) => template_expression.tag().is_none(),
             _ => false,
         }
     })
@@ -373,6 +373,12 @@ fn extract_string_value(expression: &Option<AnyJsExpression>) -> Option<String>
         }
 
         Some(AnyJsExpression::JsTemplateExpression(template_expression)) => {
+            // Tagged templates (e.g. sql`query`) have different semantics and
+            // their string value cannot be extracted.
+            if template_expression.tag().is_some() {
+                return None;
+            }
+
             let is_useless_template_literal = template_expression
                 .elements()
                 .into_iter()

crates/biome_js_analyze/tests/specs/complexity/noUselessStringConcat/valid.js

@@ -18,3 +18,7 @@ const stylisticConcatLeading = 'foo' // formatting
 const stylisticConcatLeading = `foo`
                         + 'bar'
                         + `baz`
+// Tagged templates should not be treated as plain strings
+const a = t`translate-me` + "!"
+const a = "prefix" + sql`query`
+const a = tag`a` + tag`b`

crates/biome_js_analyze/tests/specs/complexity/noUselessStringConcat/valid.js.snap

@@ -1,5 +1,6 @@
 ---
 source: crates/biome_js_analyze/tests/spec_tests.rs
+assertion_line: 149
 expression: valid.js
 ---
 # Input
@@ -24,5 +25,9 @@ const stylisticConcatLeading = 'foo' // formatting
 const stylisticConcatLeading = `foo`
                         + 'bar'
                         + `baz`
+// Tagged templates should not be treated as plain strings
+const a = t`translate-me` + "!"
+const a = "prefix" + sql`query`
+const a = tag`a` + tag`b`
 
 ```