Added diff support for serde_json Value

.travis.yml

@@ -7,6 +7,6 @@ rust:
 - beta
 - nightly
 script:
-- cargo test --features=with-rustc-serialize
+- cargo test --all-features
 - cargo doc
 

Cargo.toml

@@ -10,7 +10,9 @@ version = "0.1.0"
 
 [dependencies]
 rustc-serialize = {version = "0.3.22", optional = true}
+serde_json = {version = "0.9", optional = true}
 
 [features]
 with-rustc-serialize = ["rustc-serialize"]
+with-serde-json = ["serde_json"]
 

src/lib.rs

@@ -1,6 +1,8 @@
 //! See what's different in arbitrary data structures.
 #[cfg(feature = "with-rustc-serialize")]
 extern crate rustc_serialize;
+#[cfg(feature = "with-serde-json")]
+extern crate serde_json;
 
 
 mod traitdef;

src/value/json/mod.rs

@@ -1,3 +1,9 @@
 
+mod shared;
+pub use self::shared::*;
+
 #[cfg(feature = "with-rustc-serialize")]
 pub mod rustc_serialize;
+
+#[cfg(feature = "with-serde-json")]
+pub mod serde_json;

src/value/json/rustc_serialize.rs

@@ -3,12 +3,7 @@ use rustc_serialize::json::{Object, Json};
 use merger::Mergeable;
 use std::mem;
 use std::collections::btree_map::Entry::*;
-
-#[derive(Debug, Clone, PartialEq, Eq, Ord, PartialOrd)]
-pub enum JsonKey {
-    Index(usize),
-    String(String),
-}
+use super::JsonKey;
 
 impl Value for Json {
     type Item = Json;

src/value/json/serde_json.rs

@@ -0,0 +1,19 @@
+use traitdef::Value;
+use super::JsonKey;
+use serde_json::Value as Json;
+
+impl Value for Json {
+    type Item = Json;
+    type Key = JsonKey;
+    fn items<'a>(&'a self) -> Option<Box<Iterator<Item = (Self::Key, &'a Self::Item)> + 'a>> {
+        match *self {
+            Json::String(_) | Json::Number(_) | Json::Bool(_) | Json::Null => None,
+            Json::Array(ref inner) => {
+                Some(Box::new(inner.iter().enumerate().map(|(i, v)| (JsonKey::Index(i), v))))
+            }
+            Json::Object(ref inner) => {
+                Some(Box::new(inner.iter().map(|(s, v)| (JsonKey::String(s.clone()), v))))
+            }
+        }
+    }
+}

src/value/json/shared.rs

@@ -0,0 +1,5 @@
+#[derive(Debug, Clone, PartialEq, Eq, Ord, PartialOrd)]
+pub enum JsonKey {
+    Index(usize),
+    String(String),
+}

tests/diff.rs

@@ -5,7 +5,7 @@ extern crate treediff;
 mod diff {
     extern crate rustc_serialize;
     use treediff::{diff, Recorder};
-    use treediff::value::json::rustc_serialize::JsonKey;
+    use treediff::value::json::JsonKey;
     use self::rustc_serialize::json::Json;
     use treediff::ChangeType::*;
 

tests/json_value.rs

@@ -1,7 +1,10 @@
 extern crate treediff;
 
 macro_rules! make_suite {
-    ($make:ident, $index:tt, $null:expr, $bool:expr) => {
+    ($make:ident, $null:expr, $bool:expr) => {
+        use treediff::Value;
+        use treediff::value::json::JsonKey;
+
         #[test]
         fn scalar_values() {
             for v in &["null", "true", "1.23", "-1234456", "1234456", "\"string\""] {
@@ -14,16 +17,16 @@ macro_rules! make_suite {
         fn array() {
             let j = $make(r#"[null, true]"#);
             assert_eq!(j.items().unwrap().collect::<Vec<_>>(),
-                       vec![($index::Index(0), &$null),
-                            ($index::Index(1), &$bool(true))]);
+                       vec![(JsonKey::Index(0), &$null),
+                            (JsonKey::Index(1), &$bool(true))]);
         }
 
         #[test]
         fn object() {
             let j = $make(r#"{"a": null, "b": true}"#);
             assert_eq!(j.items().unwrap().collect::<Vec<_>>(),
-                       vec![($index::String("a".into()), &$null),
-                            ($index::String("b".into()), &$bool(true))]);
+                       vec![(JsonKey::String("a".into()), &$null),
+                            (JsonKey::String("b".into()), &$bool(true))]);
         }
 
         #[test]
@@ -35,18 +38,26 @@ macro_rules! make_suite {
 }
 
 
+#[cfg(feature = "with-serde-json")]
+mod serde_json {
+    extern crate serde_json;
+    use self::serde_json::Value as Json;
+
+    fn make_json(v: &str) -> Json {
+        v.parse().unwrap()
+    }
+
+    make_suite!(make_json, Json::Null, Json::Bool);
+}
+
 #[cfg(feature = "with-rustc-serialize")]
 mod rustc_serialize {
     extern crate rustc_serialize;
-    use treediff::value::json::rustc_serialize::JsonKey;
     use self::rustc_serialize::json::Json;
-    use treediff::Value;
 
     fn make_json(v: &str) -> Json {
         v.parse().unwrap()
     }
 
-    make_suite!(make_json, JsonKey, Json::Null, Json::Boolean);
-
-
+    make_suite!(make_json, Json::Null, Json::Boolean);
 }