1 files changed, 121 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/sharedbuf/slice.js b/js/src/jit-test/tests/sharedbuf/slice.js
new file mode 100644
index 0000000000..0ae188e79f
--- /dev/null
+++ b/js/src/jit-test/tests/sharedbuf/slice.js
@@ -0,0 +1,121 @@
+// |jit-test| skip-if: !this.SharedArrayBuffer
+
+// SharedArrayBuffer.prototype.slice
+
+load(libdir + "asserts.js");
+
+let buf = new SharedArrayBuffer(1024);
+let bufAsI8 = new Int8Array(buf);
+for ( let i=0 ; i < buf.length ; i++ )
+    bufAsI8[i] = i;
+
+let base = 10;
+let len = 10;
+
+let buf2 = buf.slice(base, base+len);
+
+// Smells right?
+assertEq(buf2 instanceof SharedArrayBuffer, true);
+assertEq(buf2.byteLength, len);
+
+// Data got copied correctly?
+let buf2AsI8 = new Int8Array(buf2);
+for ( let i=0 ; i < buf2AsI8.length ; i++ )
+    assertEq(buf2AsI8[i], bufAsI8[base+i]);
+
+// Storage not shared?
+let correct = bufAsI8[base];
+bufAsI8[base]++;
+assertEq(buf2AsI8[0], correct);
+
+// Start beyond end
+let notail = buf.slice(buf.byteLength+1);
+assertEq(notail.byteLength, 0);
+
+// Negative start
+let tail = buf.slice(-5, buf.byteLength);
+assertEq(tail.byteLength, 5);
+let tailAsI8 = new Int8Array(tail);
+for ( let i=0 ; i < tailAsI8.length ; i++ )
+    assertEq(tailAsI8[i], bufAsI8[buf.byteLength-5+i]);
+
+// Negative end
+let head = buf.slice(0, -5);
+assertEq(head.byteLength, buf.byteLength-5);
+let headAsI8 = new Int8Array(head);
+for ( let i=0 ; i < headAsI8.length ; i++ )
+    assertEq(headAsI8[i], bufAsI8[i]);
+
+// Subtyping
+class MySharedArrayBuffer1 extends SharedArrayBuffer {
+    constructor(n) { super(n) }
+}
+
+let myBuf = new MySharedArrayBuffer1(1024);
+
+let myBufAsI8 = new Int8Array(myBuf);
+for ( let i=0 ; i < myBuf.length ; i++ )
+    myBufAsI8[i] = i;
+
+let myBufSlice = myBuf.slice(0, 20);
+
+assertEq(myBufSlice instanceof MySharedArrayBuffer1, true);
+
+assertEq(myBufSlice.byteLength, 20);
+
+let myBufSliceAsI8 = new Int8Array(myBufSlice);
+for ( let i=0 ; i < myBufSlice.length ; i++ )
+    assertEq(myBufAsI8[i], myBufSliceAsI8[i]);
+
+// Error mode: the method requires an object
+assertThrowsInstanceOf(() => buf.slice.call(false, 0, 1), TypeError);
+
+// Error mode: the method is not generic.
+assertThrowsInstanceOf(() => buf.slice.call([1,2,3], 0, 1), TypeError);
+
+// Error mode (step 15): the buffer constructed on behalf of slice
+// is too short.
+
+class MySharedArrayBuffer2 extends SharedArrayBuffer {
+    constructor(n) { super(n-1) }
+}
+
+let myBuf2 = new MySharedArrayBuffer2(10);
+
+assertThrowsInstanceOf(() => myBuf2.slice(0, 5), TypeError);
+
+// Error mode (step 13): the buffer constructed on behalf of slice
+// is not a SharedArrayBuffer.
+
+let subvert = false;
+
+class MySharedArrayBuffer3 extends SharedArrayBuffer {
+    constructor(n) {
+	super(n);
+	if (subvert)
+	    return new Array(n);
+    }
+}
+
+let myBuf3 = new MySharedArrayBuffer3(10);
+
+subvert = true;
+assertThrowsInstanceOf(() => myBuf3.slice(0, 5), TypeError);
+
+// Error mode (step 14): the buffer constructed on behalf of slice
+// is the same as the input buffer.
+
+let sneaky = null;
+
+class MySharedArrayBuffer4 extends SharedArrayBuffer {
+    constructor(n) {
+	super(n);
+	if (sneaky)
+	    return sneaky;
+    }
+}
+
+let myBuf4 = new MySharedArrayBuffer4(10);
+
+sneaky = myBuf4;
+assertThrowsInstanceOf(() => myBuf4.slice(0, 5), TypeError);