biomejs · dyc3 · Feb 15, 2026 · Feb 14, 2026 · ematipico · Feb 15, 2026
diff --git a/.gitignore b/.gitignore
@@ -5,6 +5,7 @@ Profile-*.json
 .idea
 .vs
 .zed/*
+.opencode/plans/
 # Release artifacts
 **/target
 # Ignore test files that contributors could create locally

diff --git a/crates/biome_cli/tests/cases/handle_svelte_files.rs b/crates/biome_cli/tests/cases/handle_svelte_files.rs
@@ -907,3 +907,53 @@ let isChecked = false;
         result,
     ));
 }
+
+#[test]
+fn no_comma_operator_triggered_in_svelte_template_expression() {
+    let fs = MemoryFileSystem::default();
+    let mut console = BufferConsole::default();
+
+    fs.insert(
+        "biome.json".into(),
+        r#"{ "html": { "linter": {"enabled": true}, "experimentalFullSupportEnabled": true } }"#
+            .as_bytes(),
+    );
+
+    let file = Utf8Path::new("file.svelte");
+    fs.insert(
+        file.into(),
+        r#"<script>
+  let x = 1;
+</script>
+
+<!-- Comma operator in template expression - should be flagged -->
+<p>{(console.log("side effect"), x)}</p>"#
+            .as_bytes(),
+    );
+
+    let (fs, result) = run_cli(
+        fs,
+        &mut console,
+        Args::from(["lint", "--only=noCommaOperator", file.as_str()].as_slice()),
+    );
+
+    // The comma operator SHOULD be flagged in Svelte (hack only applies to Vue)
+    // Result is Ok because it's a warning, but console should contain the diagnostic
+    assert!(result.is_ok(), "run_cli returned {result:?}");
+    let has_comma_operator = console.out_buffer.iter().any(|m| {
+        let content = format!("{:?}", m.content);
+        content.contains("noCommaOperator")
+    });
+    assert!(
+        has_comma_operator,
+        "Expected noCommaOperator diagnostic in console output"
+    );
+
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "no_comma_operator_triggered_in_svelte_template_expression",
+        fs,
+        console,
+        result,
+    ));
+}
diff --git a/crates/biome_cli/tests/cases/handle_vue_files.rs b/crates/biome_cli/tests/cases/handle_vue_files.rs
@@ -1570,3 +1570,47 @@ import { mdiSquareOutline } from "@mdi/js";
         result,
     ));
 }
+
+#[test]
+fn no_comma_operator_not_triggered_in_v_for() {
+    let fs = MemoryFileSystem::default();
+    let mut console = BufferConsole::default();
+
+    fs.insert(
+        "biome.json".into(),
+        r#"{ "html": { "linter": {"enabled": true}, "experimentalFullSupportEnabled": true } }"#
+            .as_bytes(),
+    );
+
+    let file = Utf8Path::new("file.vue");
+    fs.insert(
+        file.into(),
+        r#"<template>
+  <v-list-item
+    v-for="(rate, index) in playbackRate.availablePlaybackRates.value"
+    :key="index"
+    :value="rate"
+    @click="setRate(rate)"
+  >
+    <v-list-item-title>{{ formatRate(rate) }}</v-list-item-title>
+  </v-list-item>
+</template>"#
+            .as_bytes(),
+    );
+
+    let (fs, result) = run_cli(
+        fs,
+        &mut console,
+        Args::from(["lint", "--only=noCommaOperator", file.as_str()].as_slice()),
+    );
+
+    assert!(result.is_ok(), "run_cli returned {result:?}");
+
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "no_comma_operator_not_triggered_in_v_for",
+        fs,
+        console,
+        result,
+    ));
+}
diff --git a/...es_handle_svelte_files/no_comma_operator_not_triggered_in_svelte_template_expression.snap b/...es_handle_svelte_files/no_comma_operator_not_triggered_in_svelte_template_expression.snap
@@ -0,0 +1,31 @@
+---
+source: crates/biome_cli/tests/snap_test.rs
+expression: redactor(content)
+---
+## `biome.json`
+
+```json
+{
+  "html": {
+    "linter": { "enabled": true },
+    "experimentalFullSupportEnabled": true
+  }
+}
+```
+
+## `file.svelte`
+
+```svelte
+<script>
+  let x = 1;
+</script>
+
+<!-- Comma operator in template expression - skipped by the hack -->
+<p>{(console.log("side effect"), x)}</p>
+```
+
+# Emitted Messages
+
+```block
+Checked 1 file in <TIME>. No fixes applied.
+```
diff --git a/..._cases_handle_svelte_files/no_comma_operator_triggered_in_svelte_template_expression.snap b/..._cases_handle_svelte_files/no_comma_operator_triggered_in_svelte_template_expression.snap
@@ -0,0 +1,46 @@
+---
+source: crates/biome_cli/tests/snap_test.rs
+expression: redactor(content)
+---
+## `biome.json`
+
+```json
+{
+  "html": {
+    "linter": { "enabled": true },
+    "experimentalFullSupportEnabled": true
+  }
+}
+```
+
+## `file.svelte`
+
+```svelte
+<script>
+  let x = 1;
+</script>
+
+<!-- Comma operator in template expression - should be flagged -->
+<p>{(console.log("side effect"), x)}</p>
+```
+
+# Emitted Messages
+
+```block
+file.svelte:6:32 lint/complexity/noCommaOperator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  ! The comma operator is disallowed.
+
+    5 │ <!-- Comma operator in template expression - should be flagged -->
+  > 6 │ <p>{(console.log("side effect"), x)}</p>
+      │                                ^
+
+  i Its use is often confusing and obscures side effects.
+
+
+```
+
+```block
+Checked 1 file in <TIME>. No fixes applied.
+Found 1 warning.
+```
diff --git a/...tests/snapshots/main_cases_handle_vue_files/no_comma_operator_not_triggered_in_v_for.snap b/...tests/snapshots/main_cases_handle_vue_files/no_comma_operator_not_triggered_in_v_for.snap
@@ -0,0 +1,35 @@
+---
+source: crates/biome_cli/tests/snap_test.rs
+expression: redactor(content)
+---
+## `biome.json`
+
+```json
+{
+  "html": {
+    "linter": { "enabled": true },
+    "experimentalFullSupportEnabled": true
+  }
+}
+```
+
+## `file.vue`
+
+```vue
+<template>
+  <v-list-item
+    v-for="(rate, index) in playbackRate.availablePlaybackRates.value"
+    :key="index"
+    :value="rate"
+    @click="setRate(rate)"
+  >
+    <v-list-item-title>{{ formatRate(rate) }}</v-list-item-title>
+  </v-list-item>
+</template>
+```
+
+# Emitted Messages
+
+```block
+Checked 1 file in <TIME>. No fixes applied.
+```
diff --git a/crates/biome_js_analyze/src/lint/complexity/no_comma_operator.rs b/crates/biome_js_analyze/src/lint/complexity/no_comma_operator.rs
@@ -1,7 +1,7 @@
 use biome_analyze::context::RuleContext;
 use biome_analyze::{Ast, Rule, RuleDiagnostic, RuleSource, declare_lint_rule};
 use biome_diagnostics::Severity;
-use biome_js_syntax::{JsForStatement, JsSequenceExpression};
+use biome_js_syntax::{JsFileSource, JsForStatement, JsSequenceExpression};
 use biome_rowan::AstNode;
 use biome_rule_options::no_comma_operator::NoCommaOperatorOptions;
 
@@ -66,6 +66,15 @@ impl Rule for NoCommaOperator {
                 return None;
             }
         }
+
+        // HACK: Skip in Vue template expressions (e.g., v-for="(item, index) in items")
+        // This is a temporary workaround until v-for expressions are parsed correctly
+        // https://github.com/biomejs/biome/issues/9075
+        let file_source = ctx.source_type::<JsFileSource>();
+        if file_source.is_template_expression() && file_source.as_embedding_kind().is_vue() {
+            return None;
+        }
+
         Some(())
     }