From 2a8b117c937b2a5de6d6437aa38ea42c08bc553b Mon Sep 17 00:00:00 2001
From: snek <snek@deno.com>
Date: Mon, 3 Jun 2024 13:47:57 -0700
Subject: [PATCH] feat: add DataView constructor (#1491)

---
 src/array_buffer.rs | 24 ++++++++++++++++++++++++
 src/binding.cc      |  7 +++++++
 tests/test_api.rs   | 16 ++++++++++++++++
 3 files changed, 47 insertions(+)

diff --git a/src/array_buffer.rs b/src/array_buffer.rs
index 6baa64e362..b6be735156 100644
--- a/src/array_buffer.rs
+++ b/src/array_buffer.rs
@@ -16,6 +16,7 @@ use crate::support::SharedRef;
 use crate::support::UniquePtr;
 use crate::support::UniqueRef;
 use crate::ArrayBuffer;
+use crate::DataView;
 use crate::HandleScope;
 use crate::Isolate;
 use crate::Local;
@@ -68,6 +69,12 @@ extern "C" {
   ) -> bool;
   fn v8__BackingStore__DELETE(this: *mut BackingStore);
 
+  fn v8__DataView__New(
+    arraybuffer: *const ArrayBuffer,
+    byte_offset: usize,
+    length: usize,
+  ) -> *const DataView;
+
   fn std__shared_ptr__v8__BackingStore__COPY(
     ptr: *const SharedPtrBase<BackingStore>,
   ) -> SharedPtrBase<BackingStore>;
@@ -616,3 +623,20 @@ impl ArrayBuffer {
     ))
   }
 }
+
+impl DataView {
+  /// Returns a new DataView.
+  #[inline(always)]
+  pub fn new<'s>(
+    scope: &mut HandleScope<'s>,
+    arraybuffer: Local<'s, ArrayBuffer>,
+    byte_offset: usize,
+    length: usize,
+  ) -> Local<'s, DataView> {
+    unsafe {
+      scope
+        .cast_local(|_| v8__DataView__New(&*arraybuffer, byte_offset, length))
+    }
+    .unwrap()
+  }
+}
diff --git a/src/binding.cc b/src/binding.cc
index c25a668aac..9461dc1195 100644
--- a/src/binding.cc
+++ b/src/binding.cc
@@ -1802,6 +1802,13 @@ size_t v8__ArrayBuffer__ByteLength(const v8::ArrayBuffer& self) {
   return self.ByteLength();
 }
 
+const v8::DataView* v8__DataView__New(
+    const v8::ArrayBuffer& ab,
+    size_t offset,
+    size_t length) {
+  return local_to_ptr(v8::DataView::New(ptr_to_local(&ab), offset, length));
+}
+
 struct InternalFieldData {
   uint32_t data;
 };
diff --git a/tests/test_api.rs b/tests/test_api.rs
index fe31b99d3f..51d3d4163c 100644
--- a/tests/test_api.rs
+++ b/tests/test_api.rs
@@ -734,6 +734,22 @@ fn handles_from_isolate() {
   let _ = v8::Boolean::new(isolate, true);
 }
 
+#[test]
+fn data_view() {
+  let _setup_guard = setup::parallel_test();
+  let isolate = &mut v8::Isolate::new(Default::default());
+  {
+    let scope = &mut v8::HandleScope::new(isolate);
+    let context = v8::Context::new(scope);
+    let scope = &mut v8::ContextScope::new(scope, context);
+
+    let ab = v8::ArrayBuffer::new(scope, 42);
+
+    let dv = v8::DataView::new(scope, ab, 0, 42);
+    assert!(dv.is_data_view());
+  }
+}
+
 #[test]
 fn array_buffer() {
   let _setup_guard = setup::parallel_test();