Support serde's JSON type

.travis.yml

@@ -5,8 +5,8 @@ before_script:
 - "./.travis/setup.sh"
 script:
 - cargo test
-- cargo test --features "uuid rustc-serialize time unix_socket"
-- cargo doc --no-deps --features "uuid rustc-serialize time unix_socket"
+- cargo test --features "uuid rustc-serialize time unix_socket serde"
+- cargo doc --no-deps --features "uuid rustc-serialize time unix_socket serde"
 after_success:
   - test $TRAVIS_PULL_REQUEST == "false" && test $TRAVIS_BRANCH == "master" && ./.travis/update_docs.sh
 env:

Cargo.toml

@@ -33,6 +33,7 @@ debug-builders = "0.1"
 uuid = { version = "0.1", optional = true }
 unix_socket = { version = "0.3", optional = true }
 time = { version = "0.1.14", optional = true }
+serde = { version = "0.3", optional = true }
 
 [dev-dependencies]
 url = "0.2"

README.md

@@ -243,17 +243,22 @@ OSX, BSD and Linux.
 ### UUID type
 
 [UUID](http://www.postgresql.org/docs/9.4/static/datatype-uuid.html) support is
-provided optionally by the `uuid` feature.
+provided optionally by the `uuid` feature, which adds `ToSql` and `FromSql`
+implementations for `uuid`'s `Uuid` type.
 
 ### JSON/JSONB types
 
 [JSON and JSONB](http://www.postgresql.org/docs/9.4/static/datatype-json.html)
-support is provided optionally by the `rustc-serialize` feature.
+support is provided optionally by the `rustc-serialize` feature, which adds
+`ToSql` and `FromSql` implementations for `rustc-serialize`'s `Json` type and
+the `serde` feature which adds implementations for `serde`'s `json::Value`
+type.
 
 ### TIMESTAMP/TIMESTAMPTZ types
 
 [TIMESTAMP and TIMESTAMPTZ](http://www.postgresql.org/docs/9.1/static/datatype-datetime.html)
-support is provided optionally by the `time` feature.
+support is provided optionally by the `time` feature, which adds `ToSql` and
+`FromSql` implementations for `time`'s `Timespec` type.
 
 ## Development
 Like Rust itself, Rust-Postgres is still in the early stages of development, so

src/types/mod.rs

@@ -48,7 +48,9 @@ mod uuid;
 mod time;
 mod slice;
 #[cfg(feature = "rustc-serialize")]
-mod json;
+mod rustc_serialize;
+#[cfg(feature = "serde")]
+mod serde;
 
 /// A Postgres OID
 pub type Oid = u32;

src/types/serde.rs

@@ -0,0 +1,37 @@
+extern crate serde;
+
+use std::io::prelude::*;
+use byteorder::{ReadBytesExt, WriteBytesExt};
+use self::serde::json::{self, Value};
+
+use {Result, Error};
+use types::{FromSql, ToSql, IsNull, Type};
+
+impl FromSql for Value {
+    fn from_sql<R: Read>(ty: &Type, raw: &mut R) -> Result<Value> {
+        if let Type::Jsonb = *ty {
+            // We only support version 1 of the jsonb binary format
+            if try!(raw.read_u8()) != 1 {
+                return Err(Error::BadResponse);
+            }
+        }
+        json::de::from_reader(raw).map_err(|_| Error::BadResponse)
+    }
+
+    accepts!(Type::Json, Type::Jsonb);
+}
+
+impl ToSql for Value {
+    fn to_sql<W: Write+?Sized>(&self, ty: &Type, mut out: &mut W) -> Result<IsNull> {
+        if let Type::Jsonb = *ty {
+            try!(out.write_u8(1));
+        }
+
+        try!(write!(out, "{:?}", self));
+
+        Ok(IsNull::No)
+    }
+
+    accepts!(Type::Json, Type::Jsonb);
+    to_sql_checked!();
+}

tests/types/mod.rs

@@ -11,7 +11,9 @@ mod uuid;
 #[cfg(feature = "time")]
 mod time;
 #[cfg(feature = "rustc-serialize")]
-mod json;
+mod rustc_serialize;
+#[cfg(feature = "serde")]
+mod serde;
 
 fn test_type<T: PartialEq+FromSql+ToSql, S: fmt::Display>(sql_type: &str, checks: &[(T, S)]) {
     let conn = or_panic!(Connection::connect("postgres://postgres@localhost", &SslMode::None));

tests/types/rustc_serialize.rs

@@ -13,7 +13,6 @@ fn test_json_params() {
 
 #[test]
 fn test_jsonb_params() {
-    if option_env!("TRAVIS").is_some() { return } // Travis doesn't have Postgres 9.4 yet
     test_type("JSONB", &[(Some(Json::from_str("[10, 11, 12]").unwrap()),
                           "'[10, 11, 12]'"),
                          (Some(Json::from_str("{\"f\": \"asd\"}").unwrap()),

tests/types/serde.rs

@@ -0,0 +1,22 @@
+extern crate serde;
+
+use self::serde::json::{self, Value};
+use types::test_type;
+
+#[test]
+fn test_json_params() {
+    test_type("JSON", &[(Some(json::from_str::<Value>("[10, 11, 12]").unwrap()),
+                        "'[10, 11, 12]'"),
+                       (Some(json::from_str::<Value>("{\"f\": \"asd\"}").unwrap()),
+                        "'{\"f\": \"asd\"}'"),
+                       (None, "NULL")])
+}
+
+#[test]
+fn test_jsonb_params() {
+    test_type("JSONB", &[(Some(json::from_str::<Value>("[10, 11, 12]").unwrap()),
+                          "'[10, 11, 12]'"),
+                         (Some(json::from_str::<Value>("{\"f\": \"asd\"}").unwrap()),
+                          "'{\"f\": \"asd\"}'"),
+                         (None, "NULL")])
+}