Merge pull request #1066 from napi-rs/issue/deref-u8-array

fix(napi): deref from Uint8ClampedArray

crates/napi/src/js_values/arraybuffer.rs

@@ -263,7 +263,8 @@ impl JsTypedArray {
 impl JsTypedArrayValue {
   #[inline]
   fn is_valid_as_ref(&self, dest_type: TypedArrayType) {
-    if self.typedarray_type == TypedArrayType::Uint8Clamped && dest_type != TypedArrayType::Uint8 {
+    // deref `Uint8ClampedArray` as `&[u8]` is valid
+    if self.typedarray_type == TypedArrayType::Uint8Clamped && dest_type == TypedArrayType::Uint8 {
       return;
     }
     if self.typedarray_type != dest_type {

examples/napi/__test__/typegen.spec.ts.md

@@ -145,6 +145,7 @@ Generated by [AVA](https://avajs.dev).
     export function convertU32Array(input: Uint32Array): Array<number>␊
     export function createExternalTypedArray(): Uint32Array␊
     export function mutateTypedArray(input: Float32Array): void␊
+    export function derefUint8Array(a: Uint8Array, b: Uint8ClampedArray): number␊
     /**␊
      * \`constructor\` option for \`struct\` requires all fields to be public,␊
      * otherwise tag impl fn as constructor␊

examples/napi/__test__/values.spec.ts

@@ -83,6 +83,7 @@ import {
   testSerdeRoundtrip,
   createObjWithProperty,
   dateToNumber,
+  derefUint8Array,
 } from '../'
 
 test('export const', (t) => {
@@ -358,6 +359,13 @@ test('mutate TypedArray', (t) => {
   t.deepEqual(input, new Float32Array([2.0, 4.0, 6.0, 8.0, 10.0]))
 })
 
+test('deref uint8 array', (t) => {
+  t.is(
+    derefUint8Array(new Uint8Array([1, 2]), new Uint8ClampedArray([3, 4])),
+    4,
+  )
+})
+
 test('async', async (t) => {
   const bufPromise = readFileAsync(join(__dirname, '../package.json'))
   await t.notThrowsAsync(bufPromise)

examples/napi/index.d.ts

@@ -135,6 +135,7 @@ export function appendBuffer(buf: Buffer): Buffer
 export function convertU32Array(input: Uint32Array): Array<number>
 export function createExternalTypedArray(): Uint32Array
 export function mutateTypedArray(input: Float32Array): void
+export function derefUint8Array(a: Uint8Array, b: Uint8ClampedArray): number
 /**
  * `constructor` option for `struct` requires all fields to be public,
  * otherwise tag impl fn as constructor

examples/napi/src/typed_array.rs

@@ -28,3 +28,8 @@ fn mutate_typed_array(mut input: Float32Array) {
     *item *= 2.0;
   }
 }
+
+#[napi]
+fn deref_uint8_array(a: Uint8Array, b: Uint8ClampedArray) -> u32 {
+  (a.len() + b.len()) as u32
+}