--- /dev/null	2018-12-11 16:56:58.027999799 +0100
+++ new/test/jdk/java/util/HashMap/ResizeTest.java	2018-12-11 19:51:02.532403368 +0100
@@ -0,0 +1,90 @@
+import org.testng.annotations.Test;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+import java.lang.invoke.VarHandle;
+import java.util.HashMap;
+import java.util.stream.IntStream;
+
+import static java.util.stream.Collectors.toMap;
+import static org.testng.Assert.assertEquals;
+
+/**
+ * @test
+ * @bug 8210280
+ * @run testng ResizeTest
+ */
+
+public class ResizeTest {
+    final MethodHandle TABLE_SIZE_FOR;
+    final MethodHandle RESIZE;
+    final VarHandle THRESHOLD;
+    final VarHandle TABLE;
+
+    public ResizeTest() throws IllegalAccessException, NoSuchMethodException, NoSuchFieldException,
+                                       ClassNotFoundException {
+        Class<?> mClass = HashMap.class;
+        String nodeClassName = mClass.getName() + "$Node";
+        Class<?> nodeArrayClass = Class.forName("[L" + nodeClassName + ";");
+        MethodHandles.Lookup lookup = MethodHandles.privateLookupIn(mClass, MethodHandles.lookup());
+        TABLE = lookup.findVarHandle(mClass, "table", nodeArrayClass);
+        this.TABLE_SIZE_FOR = lookup.findStatic(
+                mClass, "tableSizeFor",
+                MethodType.methodType(int.class, int.class));
+        this.RESIZE = lookup.findVirtual(mClass, "resize", MethodType.methodType(nodeArrayClass, int.class));
+        this.THRESHOLD = lookup.findVarHandle(mClass, "threshold", int.class);
+    }
+
+    int tableSizeFor(int n) {
+        try {
+            return (int) TABLE_SIZE_FOR.invoke(n);
+        } catch (Throwable t) { throw new AssertionError(t); }
+    }
+
+    @Test
+    public void testTableSizeFor() {
+        assertEquals(tableSizeFor(0), 1);
+        assertEquals(tableSizeFor(1), 1);
+        assertEquals(tableSizeFor(2), 2);
+        assertEquals(tableSizeFor(3), 4);
+        assertEquals(tableSizeFor(15), 16);
+        assertEquals(tableSizeFor(16), 16);
+        assertEquals(tableSizeFor(17), 32);
+        int maxSize = 1 << 30;
+        assertEquals(tableSizeFor(maxSize - 1), maxSize);
+        assertEquals(tableSizeFor(maxSize), maxSize);
+        assertEquals(tableSizeFor(maxSize + 1), maxSize);
+        assertEquals(tableSizeFor(Integer.MAX_VALUE), maxSize);
+    }
+
+    @Test
+    public void putAllCapacityTest() {
+        var map = new HashMap<Integer, Integer>();
+        map.putAll(IntStream.range(0, 10).boxed().collect(toMap(i -> i, i -> i)));
+
+        int capacity = ((Object[]) TABLE.get(map)).length;
+        assertEquals(capacity, 16);
+    }
+
+    @Test
+    public void callResizeWithSizeTest() throws Throwable {
+        var map = new HashMap<Integer, Integer>();
+
+        RESIZE.invoke(map, 0);
+        int capacity = ((Object[]) TABLE.get(map)).length;
+        assertEquals(capacity, 1);
+
+        RESIZE.invoke(map, 15);
+        capacity = ((Object[]) TABLE.get(map)).length;
+        assertEquals(capacity, 16);
+
+        RESIZE.invoke(map, 256);
+        capacity = ((Object[]) TABLE.get(map)).length;
+        assertEquals(capacity, 256);
+
+        RESIZE.invoke(map, 257);
+        capacity = ((Object[]) TABLE.get(map)).length;
+        assertEquals(capacity, 512);
+    }
+}