1 files changed, 74 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/basic/dictionary-delete-compact.js b/js/src/jit-test/tests/basic/dictionary-delete-compact.js
new file mode 100644
index 0000000000..73887c978c
--- /dev/null
+++ b/js/src/jit-test/tests/basic/dictionary-delete-compact.js
@@ -0,0 +1,74 @@
+// Stress test dictionary object/map property deletion/addition/compaction.
+
+const numProps = 1000;
+
+// Delete a range of properties and check correctness.
+function deleteRange(deleteStart, deleteEnd) {
+    for (var i = 0; i < numProps; i++) {
+        o["x" + i] = i;
+    }
+    for (var i = deleteStart; i < deleteEnd; i++) {
+        delete o["x" + i];
+    }
+    assertEq(Object.getOwnPropertyNames(o).length,
+             numProps - (deleteEnd - deleteStart));
+    for (var i = 0; i < numProps; i++) {
+        if (deleteStart <= i && i < deleteEnd) {
+            assertEq(("x" + i) in o, false);
+        } else {
+            assertEq(o["x" + i], i);
+        }
+    }
+}
+
+// For every "stride" properties, delete all of them except one.
+function deleteMany(stride) {
+    for (var i = 0; i < numProps; i++) {
+        o["x" + i] = i;
+    }
+    var propsNotDeleted = 0;
+    for (var i = 0; i < numProps; i++) {
+        if ((i % stride) === 1) {
+            propsNotDeleted++;
+            continue;
+        }
+        delete o["x" + i];
+    }
+    assertEq(Object.getOwnPropertyNames(o).length, propsNotDeleted);
+    for (var i = 0; i < numProps; i++) {
+        if ((i % stride) !== 1) {
+            assertEq(("x" + i) in o, false);
+        } else {
+            assertEq(o["x" + i], i);
+        }
+    }
+}
+
+var o = {};
+
+function test(useFreshObject) {
+    function testOne(f) {
+        if (useFreshObject) {
+            o = {};
+        }
+        f();
+    }
+
+    for (var i = 6; i < 12; i++) {
+        testOne(_ => deleteRange(i, 1000));
+    }
+    testOne(_ => deleteRange(100, 1000));
+    testOne(_ => deleteRange(0, 1000));
+    testOne(_ => deleteRange(1, 1000));
+    testOne(_ => deleteRange(8, 990));
+
+    testOne(_ => deleteMany(3));
+    testOne(_ => deleteMany(7));
+    testOne(_ => deleteMany(8));
+    testOne(_ => deleteMany(15));
+    testOne(_ => deleteMany(111));
+}
+
+test(true);
+o = {};
+test(false);