test: fix tests after V8 6.0 GC changes

test/object.js

@@ -21,7 +21,7 @@ describe('Object', function () {
     assert.deepEqual(obj, out)
   })
 
-  it('should retain references to written Objects', function () {
+  it('should retain references to written Objects', function (done) {
     var o_gc = false
     var buf_gc = false
     var o = { foo: 'bar' }
@@ -41,9 +41,12 @@ describe('Object', function () {
 
     // now GC `buf`
     buf = null
-    gc()
-    assert(buf_gc, '"buf" has not been garbage collected')
-    assert(o_gc, '"o" has not been garbage collected')
+    setImmediate(function () {
+      gc()
+      assert(buf_gc, '"buf" has not been garbage collected')
+      assert(o_gc, '"o" has not been garbage collected')
+      done()
+    });
   })
 
   it('should throw an Error when reading an Object from the NULL pointer', function () {

test/pointer.js

@@ -20,7 +20,7 @@ describe('pointer', function () {
     assert.strictEqual(ref.address(out), ref.address(test))
   })
 
-  it('should retain references to a written pointer in a Buffer', function () {
+  it('should retain references to a written pointer in a Buffer', function (done) {
     var child_gc = false
     var parent_gc = false
     var child = new Buffer('a pointer holding some data...')
@@ -40,9 +40,12 @@ describe('pointer', function () {
 
     // now GC `parent`
     parent = null
-    gc()
-    assert(parent_gc, '"parent" has not been garbage collected')
-    assert(child_gc, '"child" has not been garbage collected')
+    setImmediate(function () {
+      gc()
+      assert(parent_gc, '"parent" has not been garbage collected')
+      assert(child_gc, '"child" has not been garbage collected')
+      done()
+    });
   })
 
   it('should throw an Error when reading from the NULL pointer', function () {