properly serialize null values (#102)

Cargo.toml

@@ -24,7 +24,6 @@ version = "0.1.2"
 async-trait = "0.1.83"
 axum = "0.6.20"
 base64 = "0.22.1"
-bytes = "1.9.0"
 clap = "4.5.20"
 color-eyre = "0.6.3"
 console-subscriber = "0.3.0"

crates/googleapis/Cargo.toml

@@ -8,7 +8,6 @@ doctest = false
 
 [dependencies]
 base64 = { workspace = true }
-bytes = { workspace = true }
 prost = { workspace = true }
 serde = { workspace = true, features = ["serde_derive"] }
 thiserror = { workspace = true }
@@ -21,6 +20,7 @@ tonic-build = { workspace = true }
 [dev-dependencies]
 itertools = { workspace = true }
 rstest = { workspace = true }
+serde_json = { workspace = true }
 
 # Do not use workspace lints here, because generated code is not that clean.
 [lints.rust]

crates/googleapis/build.rs

@@ -26,7 +26,11 @@ fn main() {
         .enum_attribute(".google.firestore.v1.Value", "#[serde(untagged)]")
         .field_attribute(
             "bytes_value",
-            r#"#[serde(serialize_with="crate::bytes_base64::serialize")]"#,
+            r#"#[serde(serialize_with="crate::ser::as_base64")]"#,
+        )
+        .field_attribute(
+            "value_type.null_value",
+            r#"#[serde(serialize_with="crate::ser::as_null")]"#,
         )
         .compile(
             &["include/google/firestore/v1/firestore.proto"],

crates/googleapis/src/lib.rs

@@ -3,7 +3,7 @@
 
 tonic::include_proto!("googleapis");
 
-mod bytes_base64;
+mod ser;
 mod timestamp_ext;
 mod transaction_options_ext;
 mod value_ext;

crates/googleapis/src/ser.rs

@@ -0,0 +1,28 @@
+use base64::{display::Base64Display, prelude::BASE64_STANDARD_NO_PAD};
+use serde::Serializer;
+
+pub(crate) fn as_base64<T: AsRef<[u8]>, S: Serializer>(v: T, s: S) -> Result<S::Ok, S::Error> {
+    s.collect_str(&Base64Display::new(v.as_ref(), &BASE64_STANDARD_NO_PAD))
+}
+
+pub(crate) fn as_null<T, S: Serializer>(_v: T, s: S) -> Result<S::Ok, S::Error> {
+    s.serialize_unit()
+}
+
+#[cfg(test)]
+mod tests {
+    use prost::bytes::Bytes;
+
+    use crate::google::firestore::v1::{value::ValueType, Value};
+
+    #[test]
+    fn serialization() {
+        let values = [
+            Value::null(),
+            Value {
+                value_type: Some(ValueType::BytesValue(Bytes::from_static(b"\xff\xff\xbe"))),
+            },
+        ];
+        assert_eq!(serde_json::to_string(&values).unwrap(), r#"[null,"//++"]"#);
+    }
+}

crates/googleapis/src/value_ext.rs

@@ -266,14 +266,13 @@ impl PartialOrd for LatLng {
 const REFERENCE_NAME_MIN_ID: &str = "__id-9223372036854775808__";
 
 fn prep_ref_for_cmp(path: &str) -> Cow<str> {
-    (|| -> Option<Cow<str>> {
+    (|| {
         let path = path.strip_suffix(REFERENCE_NAME_MIN_ID)?;
         let collection = path.strip_suffix('/')?;
-        let result = match collection.strip_suffix('\0') {
-            Some(collection) => Cow::Owned(collection.to_string() + "@"),
-            None => Cow::Borrowed(path),
-        };
-        Some(result)
+        match collection.strip_suffix('\0') {
+            Some(collection) => Some(Cow::Owned(collection.to_string() + "@")),
+            None => Some(Cow::Borrowed(path)),
+        }
     })()
     .unwrap_or(Cow::Borrowed(path))
 }