From 23cb0ea656cd7447c80a3b31c17d629485a6a7d9 Mon Sep 17 00:00:00 2001
From: Andrew Chin <achin@eminence32.net>
Date: Thu, 9 Aug 2018 20:54:13 -0400
Subject: [PATCH] Add initial support and tests for JSON

---
 crates/js-sys/src/lib.rs         | 25 ++++++++++++
 crates/js-sys/tests/wasm/JSON.rs | 69 ++++++++++++++++++++++++++++++++
 crates/js-sys/tests/wasm/main.rs |  1 +
 3 files changed, 95 insertions(+)
 create mode 100644 crates/js-sys/tests/wasm/JSON.rs

diff --git a/crates/js-sys/src/lib.rs b/crates/js-sys/src/lib.rs
index e0f01f7bc..caaf9cdac 100644
--- a/crates/js-sys/src/lib.rs
+++ b/crates/js-sys/src/lib.rs
@@ -2663,6 +2663,31 @@ extern "C" {
     pub fn validate(bufferSource: &JsValue) -> Result<bool, JsValue>;
 }
 
+// JSON
+#[wasm_bindgen]
+extern "C" {
+
+    #[derive(Clone, Debug)]
+    pub type JSON;
+
+    /// The `JSON.parse()` method parses a JSON string, constructing the
+    /// JavaScript value or object described by the string.
+    ///
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse
+    #[wasm_bindgen(catch, static_method_of = JSON)]
+    pub fn parse(text: &str) -> Result<JsValue, JsValue>;
+
+    /// The JSON.stringify() method converts a JavaScript value to a JSON string,
+    /// optionally replacing values if a replacer function is specified or
+    /// optionally including only the specified properties if a replacer array is
+    /// specified.
+    ///
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
+    #[wasm_bindgen(static_method_of = JSON)]
+    pub fn stringify(obj: &JsValue) -> JsString;
+
+}
+
 // JsString
 #[wasm_bindgen]
 extern "C" {
diff --git a/crates/js-sys/tests/wasm/JSON.rs b/crates/js-sys/tests/wasm/JSON.rs
new file mode 100644
index 000000000..70ece6e8f
--- /dev/null
+++ b/crates/js-sys/tests/wasm/JSON.rs
@@ -0,0 +1,69 @@
+use wasm_bindgen::JsValue;
+use wasm_bindgen_test::*;
+use wasm_bindgen::JsCast;
+use js_sys::*;
+
+#[wasm_bindgen_test]
+fn parse_array() {
+
+    let js_array = JSON::parse("[1, 2, 3]").unwrap();;
+    assert!(Array::is_array(&js_array));
+
+    let array = Array::from(&js_array);
+    assert_eq!(array.length(), 3);
+    assert_eq!(array.pop(), 3);
+    assert_eq!(array.pop(), 2);
+    assert_eq!(array.pop(), 1);
+
+}
+
+#[wasm_bindgen_test]
+fn parse_object() {
+
+    let js_object = JSON::parse("{\"x\": 5, \"y\": true, \"z\": [\"foo\", \"bar\"]}").unwrap();
+    assert!(js_object.is_object());
+
+    let obj = Object::from(js_object);
+    let keys = Object::keys(&obj);
+    assert_eq!(keys.length(), 3);
+    assert_eq!(keys.pop().as_string().unwrap(), "z");
+    assert_eq!(keys.pop().as_string().unwrap(), "y");
+    assert_eq!(keys.pop().as_string().unwrap(), "x");
+
+    let values = Object::values(&obj);
+    assert_eq!(values.length(), 3);
+
+    let z = values.pop();
+    assert!(Array::is_array(&z));
+    let z_array = Array::from(&z);
+    assert_eq!(z_array.length(), 2);
+
+    let y = values.pop();
+    assert_eq!(y.as_bool(), Some(true));
+
+    let x = values.pop();
+    assert!(Number::is_integer(&x));
+    let x_num = Number::new(&x);
+    assert_eq!(x_num.value_of(), 5.0);
+
+}
+
+#[wasm_bindgen_test]
+fn parse_error() {
+    let js_object = JSON::parse("invalid json");
+    assert!(js_object.is_err());
+    let err = js_object.unwrap_err();
+    assert!(err.is_instance_of::<Error>());
+}
+
+#[wasm_bindgen_test]
+fn stringify() {
+    let arr = Array::new();
+    arr.push(&JsValue::from(1));
+    arr.push(&JsValue::from(true));
+    arr.push(&JsValue::from("hello"));
+
+    let str = JSON::stringify(&JsValue::from(arr));
+    let rust_str: String = From::from(str);
+    assert_eq!(rust_str, "[1,true,\"hello\"]");
+}
\ No newline at end of file
diff --git a/crates/js-sys/tests/wasm/main.rs b/crates/js-sys/tests/wasm/main.rs
index 1c4414b07..fdc5bbef4 100755
--- a/crates/js-sys/tests/wasm/main.rs
+++ b/crates/js-sys/tests/wasm/main.rs
@@ -18,6 +18,7 @@ pub mod Function;
 pub mod Generator;
 pub mod Intl;
 pub mod JsString;
+pub mod JSON;
 pub mod Map;
 pub mod MapIterator;
 pub mod Math;