From e05b1ae6ba9127b9b6c1869cc83f670c53813b6e Mon Sep 17 00:00:00 2001
From: Jonathan Sundqvist <sundqvist.jonathan@gmail.com>
Date: Mon, 25 Jun 2018 22:47:21 +0200
Subject: [PATCH] Add clz32 to Math

---
 src/js.rs                    |  7 +++++++
 tests/all/js_globals/Math.rs | 27 +++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/src/js.rs b/src/js.rs
index 3221ebad5..1dad9a926 100644
--- a/src/js.rs
+++ b/src/js.rs
@@ -308,6 +308,13 @@ extern {
     /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/ceil
     #[wasm_bindgen(static_method_of = Math)]
     pub fn ceil(x: f32) -> Number;
+
+    /// The Math.clz32() function returns the number of leading zero bits in
+    /// the 32-bit binary representation of a number.
+    ///
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/clz32
+    #[wasm_bindgen(static_method_of = Math)]
+    pub fn clz32(x: i32) -> Number;
 }
 
 // Number.
diff --git a/tests/all/js_globals/Math.rs b/tests/all/js_globals/Math.rs
index a69077046..1fbf95028 100644
--- a/tests/all/js_globals/Math.rs
+++ b/tests/all/js_globals/Math.rs
@@ -265,3 +265,30 @@ fn ceil() {
         "#)
         .test()
 }
+
+#[test]
+fn clz32() {
+    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 clz32(x: i32) -> js::Number {
+                js::Math::clz32(x)
+            }
+        "#)
+        .file("test.ts", r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                assert.equal(wasm.clz32(1), 31);
+                assert.equal(wasm.clz32(1000), 22);
+            }
+        "#)
+        .test()
+}