From f5dccc96fdfdcadb177e64bb9357b901f6606e40 Mon Sep 17 00:00:00 2001
From: Boshen <boshenc@gmail.com>
Date: Tue, 30 Apr 2024 23:11:22 +0800
Subject: [PATCH] refactor(coverage): avoid an `String::from_utf8` over head
 during serialization (#3145)

---
 crates/oxc_ast/src/serialize.rs | 12 +++++++++---
 tasks/coverage/src/suite.rs     |  4 ++--
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/crates/oxc_ast/src/serialize.rs b/crates/oxc_ast/src/serialize.rs
index fbbf1bccd..3d334f5cd 100644
--- a/crates/oxc_ast/src/serialize.rs
+++ b/crates/oxc_ast/src/serialize.rs
@@ -28,11 +28,17 @@ impl serde_json::ser::Formatter for EcmaFormatter {
 impl<'a> Program<'a> {
     /// # Panics
     pub fn to_json(&self) -> String {
-        let buf = std::vec::Vec::new();
-        let mut ser = serde_json::Serializer::with_formatter(buf, crate::serialize::EcmaFormatter);
-        self.serialize(&mut ser).unwrap();
+        let ser = self.serializer();
         String::from_utf8(ser.into_inner()).unwrap()
     }
+
+    /// # Panics
+    pub fn serializer(&self) -> serde_json::Serializer<std::vec::Vec<u8>, EcmaFormatter> {
+        let buf = std::vec::Vec::new();
+        let mut ser = serde_json::Serializer::with_formatter(buf, EcmaFormatter);
+        self.serialize(&mut ser).unwrap();
+        ser
+    }
 }
 
 impl Serialize for RegExpFlags {
diff --git a/tasks/coverage/src/suite.rs b/tasks/coverage/src/suite.rs
index 445958664..f844bf907 100644
--- a/tasks/coverage/src/suite.rs
+++ b/tasks/coverage/src/suite.rs
@@ -322,8 +322,8 @@ pub trait Case: Sized + Sync + Send + UnwindSafe {
             return res;
         }
 
-        // Make sure serialization doesn't crash for ast and hir, also for code coverage.
-        let _json = parser_ret.program.to_json();
+        // Make sure serialization doesn't crash; also for code coverage.
+        let _serializer = parser_ret.program.serializer();
 
         let program = allocator.alloc(parser_ret.program);
         let semantic_ret = SemanticBuilder::new(source_text, source_type)