# Copyright 2021 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import unittest
from export_dtrace import DTraceParser


class DTraceReadTest(unittest.TestCase):
    def testEmpty(self):
        """Tests that a directory with no valid stacks triggers a failure."""

        with self.assertRaises(SystemExit):
            collapser = DTraceParser()
            collapser.ParseDir('./test_data/empty/')

    def testValidBlock(self):
        """Tests basic parsing of the DTrace format."""

        collapser = DTraceParser()
        collapser.ParseDir('./test_data/valid/')
        self.assertEqual(
            collapser.GetSamplesListForTesting(),
            [
                {
                    'frames': [
                        ('fake_module', 'baz'),
                        ('fake_module', 'bar'),
                        ('fake_module', 'foo'),
                    ],
                    'weight': 12,
                }
            ],
        )

    def testRepeatedFunction(self):
        """Tests accumulation of samples of the same function over files."""

        collapser = DTraceParser()
        collapser.ParseDir('./test_data/repeated/')
        self.assertEqual(
            collapser.GetSamplesListForTesting(),
            [
                {
                    'frames': [
                        ('fake_module', 'baz'),
                        ('fake_module', 'bar'),
                        ('fake_module', 'foo'),
                    ],
                    'weight': 24,
                }
            ],
        )

    def testUnsymbolized(self):
        """Tests that absolute addresses are parsed as unsymbolized frames."""

        collapser = DTraceParser()
        collapser.ParseDir('./test_data/absolute_offset/')
        self.assertEqual(
            collapser.GetSamplesListForTesting(),
            [
                {
                    'frames': [
                        ('unsymbolized module', '0x21'),
                        ('unsymbolized module', '+0x85'),
                        ('unsymbolized module', '0x37'),
                    ],
                    'weight': 12,
                }
            ],
        )


class StackCollapseTest(unittest.TestCase):
    def testDoublePostProcessStackSamplesFails(self):
        """Tests calling post_process_samples() twice triggers a failure."""

        samples = [
            {
                'frames': [
                    ('fake_module', 'foo'),
                    ('fake_module', 'bar'),
                    ('fake_module', 'baz'),
                ],
                'weight': 24,
            }
        ]
        stack_collapser = DTraceParser()
        stack_collapser.AddSamplesForTesting(samples)

        with self.assertRaises(SystemExit):
            stack_collapser.PostProcessStackSamples()
            stack_collapser.PostProcessStackSamples()