Fixed error in serializing json

src/io/json/write/mod.rs

@@ -1,6 +1,7 @@
 //! APIs to write to JSON
 mod format;
 mod serialize;
+mod utf8;
 pub use fallible_streaming_iterator::*;
 pub use format::*;
 pub use serialize::serialize;

src/io/json/write/serialize.rs

@@ -1,5 +1,4 @@
 use lexical_core::ToLexical;
-use serde_json::Value;
 use streaming_iterator::StreamingIterator;
 
 use crate::bitmap::utils::zip_validity;
@@ -8,6 +7,7 @@ use crate::io::iterator::BufStreamingIterator;
 use crate::util::lexical_to_bytes_mut;
 use crate::{array::*, datatypes::DataType, types::NativeType};
 
+use super::utf8::utf8_serialize;
 use super::{JsonArray, JsonFormat};
 
 fn boolean_serializer<'a>(
@@ -137,20 +137,6 @@ fn list_serializer<'a, O: Offset>(
     ))
 }
 
-#[inline]
-fn utf8_serialize(value: &str, buf: &mut Vec<u8>) {
-    if value.as_bytes().is_ascii() {
-        buf.reserve(value.len() + 2);
-        buf.push(b'"');
-        buf.extend_from_slice(value.as_bytes());
-        buf.push(b'"');
-    } else {
-        // it may contain reserved keywords: perform roundtrip for
-        // todo: avoid this roundtrip over serde_json
-        serde_json::to_writer(buf, &Value::String(value.to_string())).unwrap();
-    }
-}
-
 fn new_serializer<'a>(
     array: &'a dyn Array,
 ) -> Box<dyn StreamingIterator<Item = [u8]> + 'a + Send + Sync> {

tests/it/io/json/write.rs

@@ -301,7 +301,26 @@ fn write_escaped_utf8() -> Result<()> {
 
     assert_eq!(
         String::from_utf8(buf).unwrap().as_bytes(),
-        b"{\"c1\":\"a\na\"}\n{\"c1\":null}\n"
+        b"{\"c1\":\"a\\na\"}\n{\"c1\":null}\n"
+    );
+    Ok(())
+}
+
+#[test]
+fn write_quotation_marks_in_utf8() -> Result<()> {
+    let a = Utf8Array::<i32>::from(&vec![Some("a\"a"), None]);
+
+    let batch = Chunk::try_new(vec![&a as &dyn Array]).unwrap();
+
+    let buf = write_batch(
+        batch,
+        vec!["c1".to_string()],
+        json_write::LineDelimited::default(),
+    )?;
+
+    assert_eq!(
+        String::from_utf8(buf).unwrap().as_bytes(),
+        b"{\"c1\":\"a\\\"a\"}\n{\"c1\":null}\n"
     );
     Ok(())
 }