Add atan to Math

src/js.rs

@@ -273,6 +273,11 @@ extern {
     #[wasm_bindgen(static_method_of = Math)]
     pub fn asinh(number: i32) -> Number;
 
+    /// The Math.atan() function returns the arctangent (in radians) of a
+    /// number, that is Math.atan(x) = arctan(x) = the unique y ∊ [-π2;π2]such that
+    /// tan(y) = x
+    #[wasm_bindgen(static_method_of = Math)]
+    pub fn atan(number: i32) -> Number;
 
 }
 

tests/all/js_globals/Math.rs

@@ -134,3 +134,29 @@ fn asinh() {
         "#)
         .test()
 }
+
+#[test]
+fn atan() {
+    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 atan(number: i32) -> js::Number {
+                js::Math::atan(number)
+            }
+        "#)
+        .file("test.ts", r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                assert.equal(wasm.atan(1), Math.atan(1));
+            }
+        "#)
+        .test()
+}