Making CallStack immutable, so it can be hashable

appengine/findit/crash/test/occurrence_test.py

 # Copyright 2016 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.
 
 from common import constants
 from common.pipeline_wrapper import pipeline_handlers
 from crash.occurrence import Occurrence
 from crash.occurrence import DefaultOccurrenceRanking
 from crash.occurrence import RankByOccurrence
 from crash.stacktrace import StackFrame
@@ skipping 11 matching lines @@
     return 'class_2'
 
   def GetClassFromResult(self, _result):  # pragma: no cover.
     return 'class_3'
 
   def Classify(self, results, crash_stack):
     top_n_frames = 4
     if results:
       classes = map(self.GetClassFromResult, results[:top_n_frames])
     else:
-      classes = map(self.GetClassFromStackFrame, crash_stack[:top_n_frames])
+      classes = map(self.GetClassFromStackFrame,
+          crash_stack.frames[:top_n_frames])
 
     class_list = RankByOccurrence(classes, 1)
     if class_list:
       return class_list[0]
 
     return ''
 
 
 class ClassifierTest(CrashTestCase):
 
   def testDefaultOccurrenceRanking(self):
     self.assertEqual(DefaultOccurrenceRanking(Occurrence('c1', [0])),
         (-1, 0))
     self.assertEqual(DefaultOccurrenceRanking(Occurrence('c1', [0, 1])),
         (-float('inf'), 0))
 
   def testClassifyCrashStack(self):
     dummy_classifier = DummyClassifier()
 
     crash_stack = CallStack(0)
     self.assertEqual(dummy_classifier.Classify([], crash_stack), '')
 
-    crash_stack.extend(
-        [StackFrame(0, 'src/', 'a::c(p* &d)', 'f0.cc', 'src/f0.cc', [177]),
-         StackFrame(1, 'src/', 'a::d(a* c)', 'f1.cc', 'src/f1.cc', [227]),
-         StackFrame(2, 'src/dummy', 'a::e(int)', 'f2.cc', 'src/f2.cc', [87])])
+    crash_stack = CallStack(0, frame_list=[
+        StackFrame(0, 'src/', 'a::c(p* &d)', 'f0.cc', 'src/f0.cc', [177]),
+        StackFrame(1, 'src/', 'a::d(a* c)', 'f1.cc', 'src/f1.cc', [227]),
+        StackFrame(2, 'src/dummy', 'a::e(int)', 'f2.cc', 'src/f2.cc', [87])])
 
     self.assertEqual(dummy_classifier.Classify([], crash_stack), 'class_1')
 
-    crash_stack = CallStack(0)
-    crash_stack.extend(
-        [StackFrame(0, 'src/', 'a::c(p* &d)', 'f0.cc', 'src/f0.cc', [177]),
-         StackFrame(1, 'src/dummy', 'a::d(a* c)', 'f1.cc', 'src/f1.cc', [227]),
-         StackFrame(2, 'src/dummy', 'a::e(int)', 'f2.cc', 'src/f2.cc', [87])])
+    crash_stack = CallStack(0, frame_list=[
+        StackFrame(0, 'src/', 'a::c(p* &d)', 'f0.cc', 'src/f0.cc', [177]),
+        StackFrame(1, 'src/dummy', 'a::d(a* c)', 'f1.cc', 'src/f1.cc', [227]),
+        StackFrame(2, 'src/dummy', 'a::e(int)', 'f2.cc', 'src/f2.cc', [87])])
 
     self.assertEqual(dummy_classifier.Classify([], crash_stack), 'class_2')
 
   def testClassifyResults(self):
     dummy_classifier = DummyClassifier()
 
     result = Result(self.GetDummyChangeLog(), 'src/')
     result.file_to_stack_infos = {
         'f0.cc': [(StackFrame(
             0, 'src/', 'a::c(p* &d)', 'f0.cc', 'src/f0.cc', [177]), 0)]
     }
 
     self.assertEqual(dummy_classifier.Classify([result], CallStack(0)),
                      'class_3')