1 files changed, 63 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/cacheir/megamorphic-get-has-dense.js b/js/src/jit-test/tests/cacheir/megamorphic-get-has-dense.js
new file mode 100644
index 0000000000..b6098435a1
--- /dev/null
+++ b/js/src/jit-test/tests/cacheir/megamorphic-get-has-dense.js
@@ -0,0 +1,63 @@
+setJitCompilerOption("ic.force-megamorphic", 1);
+
+function testBasic() {
+  // Create various native objects with dense elements.
+  var objs = [[1, 2, 3], {0: 1, 1: 2, 2: 3}];
+  var fun = x => x;
+  fun[0] = 1;
+  fun[1] = 2;
+  fun[2] = 3;
+  objs.push(fun);
+  for (var i = 0; i < 20; i++) {
+    var o = {};
+    o["x" + i] = i;
+    o[0] = 1;
+    o[1] = 2;
+    if (i < 10) {
+      o[2] = 3;
+    } else {
+      // o[2] will be a hole.
+      o[3] = 4;
+    }
+    objs.push(o);
+  }
+
+  // Access their dense elements.
+  for (var i = 0; i < 10; i++) {
+    for (var j = 0; j < objs.length; j++) {
+      var obj = objs[j];
+      assertEq(obj[0], 1);
+      assertEq(obj[1], 2);
+      assertEq(obj[2], j < 13 ? 3 : undefined);
+      assertEq(obj[3], j >= 13 ? 4 : undefined);
+      assertEq(0 in obj, true);
+      assertEq(1 in obj, true);
+      assertEq(2 in obj, j < 13);
+      assertEq(3 in obj, j >= 13);
+      assertEq(Object.hasOwn(obj, 0), true);
+      assertEq(Object.hasOwn(obj, 1), true);
+      assertEq(Object.hasOwn(obj, 2), j < 13);
+      assertEq(Object.hasOwn(obj, 3), j >= 13);
+    }
+  }
+}
+testBasic();
+
+function testNonNative() {
+  var arr = [1, 2, 3];
+  var proxy = new Proxy({}, {
+    get(target, prop) { return 456; },
+    has(target, prop) { return prop === "0"; },
+  });
+  for (var i = 0; i < 100; i++) {
+    var obj = i < 95 ? arr : proxy;
+    assertEq(obj[0], i < 95 ? 1 : 456);
+    assertEq(0 in obj, true);
+    assertEq(1 in obj, i < 95);
+    assertEq(4 in obj, false);
+    assertEq(Object.hasOwn(obj, 0), i < 95);
+    assertEq(Object.hasOwn(obj, 1), i < 95);
+    assertEq(Object.hasOwn(obj, 4), false);
+  }
+}
+testNonNative();