1 files changed, 64 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/large-arraybuffers/arraybuffer-transfer.js b/js/src/jit-test/tests/large-arraybuffers/arraybuffer-transfer.js
new file mode 100644
index 0000000000..3f522e741c
--- /dev/null
+++ b/js/src/jit-test/tests/large-arraybuffers/arraybuffer-transfer.js
@@ -0,0 +1,64 @@
+const gb = 1 * 1024 * 1024 * 1024;
+
+const smallByteLength = 1024;
+const largeByteLength = 4 * gb;
+
+// Fast alternative to |assertEq| to avoid a slow VM-call.
+// Should only be used when looping over the TypedArray contents to avoid
+// unnecessary test slowdowns.
+function assertEqNum(e, a) {
+  if (e !== a) {
+    assertEq(e, a);
+  }
+}
+
+{
+  let smallBuffer = new ArrayBuffer(smallByteLength);
+
+  let i8 = new Uint8Array(smallBuffer);
+  for (let i = 0; i < smallByteLength; ++i) {
+    assertEqNum(i8[i], 0);
+    i8[i] = i;
+  }
+
+  assertEq(smallBuffer.byteLength, smallByteLength);
+  assertEq(smallBuffer.detached, false);
+
+  // Copy from a small into a large buffer.
+  let largeBuffer = smallBuffer.transfer(largeByteLength);
+
+  assertEq(smallBuffer.byteLength, 0);
+  assertEq(smallBuffer.detached, true);
+
+  assertEq(largeBuffer.byteLength, largeByteLength);
+  assertEq(largeBuffer.detached, false);
+
+  i8 = new Uint8Array(largeBuffer);
+  for (let i = 0; i < smallByteLength; ++i) {
+    assertEqNum(i8[i], i & 0xff);
+  }
+
+  // Test the first 100 new bytes.
+  for (let i = smallByteLength; i < smallByteLength + 100; ++i) {
+    assertEqNum(i8[i], 0);
+  }
+
+  // And the last 100 new bytes.
+  for (let i = largeByteLength - 100; i < largeByteLength; ++i) {
+    assertEqNum(i8[i], 0);
+  }
+
+  // Copy back from a large into a small buffer.
+  smallBuffer = largeBuffer.transfer(smallByteLength);
+
+  assertEq(largeBuffer.byteLength, 0);
+  assertEq(largeBuffer.detached, true);
+
+  assertEq(smallBuffer.byteLength, smallByteLength);
+  assertEq(smallBuffer.detached, false);
+
+  i8 = new Uint8Array(smallBuffer);
+  for (let i = 0; i < smallByteLength; ++i) {
+    assertEqNum(i8[i], i & 0xff);
+  }
+}