From f9d2dbd0b6ca2a05f2660a04cbcfacd98dec69eb Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Wed, 10 Oct 2018 15:53:50 -0700
Subject: [PATCH] js-sys: Add bindings for `TypedArray.slice`

This commit adds support for the `slice` function on all `TypedArray`
instances. The `slice` function is similar to `subarray` except that it
actually copies the data, whereas `subarray` just returns a different
view into data.
---
 crates/js-sys/src/lib.rs               | 54 ++++++++++++++++++++++++++
 crates/js-sys/tests/wasm/TypedArray.rs | 12 ++++++
 2 files changed, 66 insertions(+)

diff --git a/crates/js-sys/src/lib.rs b/crates/js-sys/src/lib.rs
index 249e89a4812..b4000db345e 100644
--- a/crates/js-sys/src/lib.rs
+++ b/crates/js-sys/src/lib.rs
@@ -719,6 +719,12 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn subarray(this: &Float32Array, begin: u32, end: u32) -> Float32Array;
 
+    /// The `slice()` method returns a shallow copy of a portion of a typed
+    /// array into a new typed array object. This method has the same algorithm
+    /// as `Array.prototype.slice()`.
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Float32Array, begin: u32, end: u32) -> Uint8ClampedArray;
+
     /// The `forEach()` method executes a provided function once per array
     /// element. This method has the same algorithm as
     /// `Array.prototype.forEach()`. `TypedArray` is one of the typed array
@@ -772,6 +778,12 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn subarray(this: &Float64Array, begin: u32, end: u32) -> Float64Array;
 
+    /// The `slice()` method returns a shallow copy of a portion of a typed
+    /// array into a new typed array object. This method has the same algorithm
+    /// as `Array.prototype.slice()`.
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Float64Array, begin: u32, end: u32) -> Uint8ClampedArray;
+
     /// The `forEach()` method executes a provided function once per array
     /// element. This method has the same algorithm as
     /// `Array.prototype.forEach()`. `TypedArray` is one of the typed array
@@ -960,6 +972,12 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn subarray(this: &Int8Array, begin: u32, end: u32) -> Int8Array;
 
+    /// The `slice()` method returns a shallow copy of a portion of a typed
+    /// array into a new typed array object. This method has the same algorithm
+    /// as `Array.prototype.slice()`.
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Int8Array, begin: u32, end: u32) -> Uint8ClampedArray;
+
     /// The `forEach()` method executes a provided function once per array
     /// element. This method has the same algorithm as
     /// `Array.prototype.forEach()`. `TypedArray` is one of the typed array
@@ -1013,6 +1031,12 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn subarray(this: &Int16Array, begin: u32, end: u32) -> Int16Array;
 
+    /// The `slice()` method returns a shallow copy of a portion of a typed
+    /// array into a new typed array object. This method has the same algorithm
+    /// as `Array.prototype.slice()`.
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Int16Array, begin: u32, end: u32) -> Uint8ClampedArray;
+
     /// The `forEach()` method executes a provided function once per array
     /// element. This method has the same algorithm as
     /// `Array.prototype.forEach()`. `TypedArray` is one of the typed array
@@ -1066,6 +1090,12 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn subarray(this: &Int32Array, begin: u32, end: u32) -> Int32Array;
 
+    /// The `slice()` method returns a shallow copy of a portion of a typed
+    /// array into a new typed array object. This method has the same algorithm
+    /// as `Array.prototype.slice()`.
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Int32Array, begin: u32, end: u32) -> Uint8ClampedArray;
+
     /// The `forEach()` method executes a provided function once per array
     /// element. This method has the same algorithm as
     /// `Array.prototype.forEach()`. `TypedArray` is one of the typed array
@@ -2803,6 +2833,12 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn subarray(this: &Uint8Array, begin: u32, end: u32) -> Uint8Array;
 
+    /// The `slice()` method returns a shallow copy of a portion of a typed
+    /// array into a new typed array object. This method has the same algorithm
+    /// as `Array.prototype.slice()`.
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Uint8Array, begin: u32, end: u32) -> Uint8ClampedArray;
+
     /// The `forEach()` method executes a provided function once per array
     /// element. This method has the same algorithm as
     /// `Array.prototype.forEach()`. `TypedArray` is one of the typed array
@@ -2858,6 +2894,12 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn subarray(this: &Uint8ClampedArray, begin: u32, end: u32) -> Uint8ClampedArray;
 
+    /// The `slice()` method returns a shallow copy of a portion of a typed
+    /// array into a new typed array object. This method has the same algorithm
+    /// as `Array.prototype.slice()`.
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Uint8ClampedArray, begin: u32, end: u32) -> Uint8ClampedArray;
+
     /// The `forEach()` method executes a provided function once per array
     /// element. This method has the same algorithm as
     /// `Array.prototype.forEach()`. `TypedArray` is one of the typed array
@@ -2911,6 +2953,12 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn subarray(this: &Uint16Array, begin: u32, end: u32) -> Uint16Array;
 
+    /// The `slice()` method returns a shallow copy of a portion of a typed
+    /// array into a new typed array object. This method has the same algorithm
+    /// as `Array.prototype.slice()`.
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Uint16Array, begin: u32, end: u32) -> Uint8ClampedArray;
+
     /// The `forEach()` method executes a provided function once per array
     /// element. This method has the same algorithm as
     /// `Array.prototype.forEach()`. `TypedArray` is one of the typed array
@@ -2964,6 +3012,12 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn subarray(this: &Uint32Array, begin: u32, end: u32) -> Uint32Array;
 
+    /// The `slice()` method returns a shallow copy of a portion of a typed
+    /// array into a new typed array object. This method has the same algorithm
+    /// as `Array.prototype.slice()`.
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Uint32Array, begin: u32, end: u32) -> Uint8ClampedArray;
+
     /// The `forEach()` method executes a provided function once per array
     /// element. This method has the same algorithm as
     /// `Array.prototype.forEach()`. `TypedArray` is one of the typed array
diff --git a/crates/js-sys/tests/wasm/TypedArray.rs b/crates/js-sys/tests/wasm/TypedArray.rs
index a4a3af344f4..8a82ba5ff04 100644
--- a/crates/js-sys/tests/wasm/TypedArray.rs
+++ b/crates/js-sys/tests/wasm/TypedArray.rs
@@ -88,3 +88,15 @@ macro_rules! test_fill {
 fn new_fill() {
     each!(test_fill);
 }
+
+macro_rules! test_slice {
+    ($arr:ident) => {{
+        let arr = $arr::new(&4.into());
+        assert_eq!(arr.length(), 4);
+        assert_eq!(arr.slice(1, 2).length(), 1);
+    }};
+}
+#[wasm_bindgen_test]
+fn new_slice() {
+    each!(test_slice);
+}