From 9633642e6ed7ff494b0b610cdd62dc9eea13c5b3 Mon Sep 17 00:00:00 2001
From: Jonathan Sundqvist <sundqvist.jonathan@gmail.com>
Date: Mon, 25 Jun 2018 21:41:28 +0200
Subject: [PATCH] Add abs to Math

---
 src/js.rs                    | 12 ++++++++++++
 tests/all/js_globals/Math.rs | 31 +++++++++++++++++++++++++++++++
 tests/all/js_globals/mod.rs  |  1 +
 3 files changed, 44 insertions(+)
 create mode 100644 tests/all/js_globals/Math.rs

diff --git a/src/js.rs b/src/js.rs
index f82573c63..e50b3b403 100644
--- a/src/js.rs
+++ b/src/js.rs
@@ -231,6 +231,18 @@ extern {
     pub fn name(this: &JsFunction) -> JsString;
 }
 
+// Math
+#[wasm_bindgen]
+extern {
+    pub type Math;
+    /// The Math.abs() function returns the absolute value of a number, that is
+    /// Math.abs(x) = |x|
+    ///
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/abs
+    #[wasm_bindgen(static_method_of = Math)]
+    pub fn abs(number: i32) -> Number;
+}
+
 // Number.
 #[wasm_bindgen]
 extern {
diff --git a/tests/all/js_globals/Math.rs b/tests/all/js_globals/Math.rs
new file mode 100644
index 000000000..98992f457
--- /dev/null
+++ b/tests/all/js_globals/Math.rs
@@ -0,0 +1,31 @@
+#![allow(non_snake_case)]
+
+use super::project;
+
+
+#[test]
+fn abs() {
+    project()
+        .file("src/lib.rs", r#"
+            #![feature(proc_macro, wasm_custom_section)]
+
+            extern crate wasm_bindgen;
+            use wasm_bindgen::prelude::*;
+            use wasm_bindgen::js;
+
+            #[wasm_bindgen]
+            pub fn abs(number: i32) -> js::Number {
+                js::Math::abs(number)
+            }
+        "#)
+        .file("test.ts", r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                assert.equal(wasm.abs(-32), Math.abs(-32));
+                assert.equal(wasm.abs(32), 32));
+            }
+        "#)
+        .test()
+}
diff --git a/tests/all/js_globals/mod.rs b/tests/all/js_globals/mod.rs
index a5d242466..3fd54d808 100644
--- a/tests/all/js_globals/mod.rs
+++ b/tests/all/js_globals/mod.rs
@@ -8,6 +8,7 @@ mod ArrayIterator;
 mod JsFunction;
 mod JsString;
 mod Number;
+mod Math;
 
 #[test]
 #[cfg(feature = "std")]