Add JS heap snapshotting functionality to Telemetry (part 2)

tools/telemetry/telemetry/core/heap/chrome_js_heap_snapshot_parser_unittest.py

Index: tools/telemetry/telemetry/core/heap/chrome_js_heap_snapshot_parser_unittest.py
diff --git a/tools/telemetry/telemetry/core/heap/chrome_js_heap_snapshot_parser_unittest.py b/tools/telemetry/telemetry/core/heap/chrome_js_heap_snapshot_parser_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..478e28b46fc031596cb1dc07a6ad08ef9c7fb961
--- /dev/null
+++ b/tools/telemetry/telemetry/core/heap/chrome_js_heap_snapshot_parser_unittest.py
@@ -0,0 +1,56 @@
+# Copyright (c) 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import json
+import unittest
+
+from telemetry.core.heap import chrome_js_heap_snapshot_parser
+
+class ChromeJsHeapSnapshotParserUnittest(unittest.TestCase):
+  def _HeapSnapshotData(self, node_types, edge_types, node_fields, edge_fields,
+                        node_list, edge_list, strings):
+    """Helper for creating heap snapshot data."""
+    return {'snapshot': {'meta': {'node_types': [node_types],
+                                  'edge_types': [edge_types],
+                                  'node_fields': node_fields,
+                                  'edge_fields': edge_fields}},
+            'nodes': node_list,
+            'edges': edge_list,
+            'strings': strings}
+
+  def testParseSimpleSnapshot(self):
+    # Create a snapshot containing 2 nodes and an edge between them.
+    node_types = ['object']
+    edge_types = ['property']
+    node_fields = ['type', 'name', 'id', 'edge_count']
+    edge_fields = ['type', 'name_or_index', 'to_node']
+    node_list = [0, 0, 0, 1,
+                 0, 1, 1, 0]
+    edge_list = [0, 2, 4]
+    strings = ['node1', 'node2', 'edge1']
+    heap = self._HeapSnapshotData(node_types, edge_types, node_fields,
+                                  edge_fields, node_list, edge_list, strings)
+    objects = list(chrome_js_heap_snapshot_parser.ChromeJsHeapSnapshotParser(
+        json.dumps(heap)).GetAllLiveHeapObjects())
+    self.assertEqual(2, len(objects))
+    if objects[0].edges_from:
+      from_ix = 0
+      to_ix = 1
+    else:
+      from_ix = 1
+      to_ix = 0
+    self.assertEqual('node1', objects[from_ix].class_name)
+    self.assertEqual('node2', objects[to_ix].class_name)
+    self.assertEqual(1, len(objects[from_ix].edges_from))
+    self.assertEqual(0, len(objects[from_ix].edges_to))
+    self.assertEqual(0, len(objects[to_ix].edges_from))
+    self.assertEqual(1, len(objects[to_ix].edges_to))
+    self.assertEqual('node1',
+                     objects[from_ix].edges_from[0].from_object.class_name)
+    self.assertEqual('node2',
+                     objects[from_ix].edges_from[0].to_object.class_name)
+    self.assertEqual('edge1', objects[from_ix].edges_from[0].name_string)
+    self.assertEqual('node1', objects[to_ix].edges_to[0].from_object.class_name)
+    self.assertEqual('node2', objects[to_ix].edges_to[0].to_object.class_name)
+    self.assertEqual('edge1', objects[to_ix].edges_to[0].name_string)