tools/metrics/histograms/extract_histograms_test.py

# Copyright 2017 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import logging
from parameterized import parameterized
import unittest
import xml.dom.minidom

import extract_histograms
import histogram_configuration_model

TEST_HISTOGRAM_WITH_TOKENS = """
<histogram-configuration>
<histograms>
<histogram name="HistogramName.{Color}{Size}" units="things"
    expires_after="2017-10-16">
  <owner>me@chromium.org</owner>
  <summary>
    This is a histogram for button of {Color} color and {Size} size.
  </summary>
  <token key="Color">
    <variant name="green">
      <owner>green@chromium.org</owner>
    </variant>
  </token>
  <token key="Size">
    <variant name="" summary="all"/>
    <variant name=".small" summary="small">
      <owner>small@chromium.org</owner>
    </variant>
    <variant name=".medium" summary="medium"/>
    <variant name=".large" summary="large"/>
  </token>
</histogram>
</histograms>
</histogram-configuration>
"""

TEST_HISTOGRAM_WITH_VARIANTS = """
<histogram-configuration>
<histograms>
<variants name="HistogramNameSize">
  <variant name="" summary="all"/>
  <variant name=".small" summary="small">
    <owner>small@chromium.org</owner>
  </variant>
  <variant name=".medium" summary="medium"/>
  <variant name=".large" summary="large"/>
</variants>

<histogram name="HistogramName.{Color}{Size}" units="things"
    expires_after="2017-10-16">
  <owner>me@chromium.org</owner>
  <summary>
    This is a histogram for button of {Color} color and {Size} size.
  </summary>
  <token key="Color">
    <variant name="green">
      <owner>green@chromium.org</owner>
    </variant>
  </token>
  <token key="Size" variants="HistogramNameSize"/>
</histogram>
</histograms>
</histogram-configuration>
"""

TEST_HISTOGRAM_WITH_IMPLICIT_VARIANTS = """
<histogram-configuration>
<histograms>
<variants name="Size">
  <variant name="" summary="all"/>
  <variant name=".small" summary="small">
    <owner>small@chromium.org</owner>
  </variant>
  <variant name=".medium" summary="medium"/>
  <variant name=".large" summary="large"/>
</variants>

<histogram name="HistogramName.{Color}{Size}" units="things"
    expires_after="2017-10-16">
  <owner>me@chromium.org</owner>
  <summary>
    This is a histogram for button of {Color} color and {Size} size.
  </summary>
  <token key="Color">
    <variant name="green">
      <owner>green@chromium.org</owner>
    </variant>
  </token>
</histogram>
</histograms>
</histogram-configuration>
"""

TEST_HISTOGRAM_TOKENS_DUPLICATE = """
<histogram-configuration>
<histograms>
<histogram name="Histogram{Color}{Size}" units="things"
    expires_after="2017-10-16">
  <owner>me@chromium.org</owner>
  <summary>
    This is a histogram for button of {Color} color and {Size} size.
  </summary>
  <token key="Color">
    <variant name="" summary="all"/>
    <variant name=".red" summary="red"/>
    <variant name=".green" summary="green"/>
  </token>
  <token key="Size">
    <variant name="" summary="all"/>
    <variant name=".red" summary="red"/>
    <variant name=".small" summary="small"/>
    <variant name=".medium" summary="medium"/>
    <variant name=".large" summary="large"/>
  </token>
</histogram>
</histograms>
</histogram-configuration>
"""

TEST_HISTOGRAM_VARIANTS_DUPLICATE = """
<histogram-configuration>
<variants name="HistogramNameSize">
  <variant name="" summary="all"/>
  <variant name=".red" summary="red"/>
  <variant name=".small" summary="small"/>
  <variant name=".medium" summary="medium"/>
  <variant name=".large" summary="large"/>
</variants>

<histograms>
<histogram name="Histogram{Color}{Size}" units="things"
    expires_after="2017-10-16">
  <owner>me@chromium.org</owner>
  <summary>
    This is a histogram for button of {Color} color and {Size} size.
  </summary>
  <token key="Color">
    <variant name="" summary="all"/>
    <variant name=".red" summary="red"/>
    <variant name=".green" summary="green"/>
  </token>
  <token key="Size" variants="HistogramNameSize"/>
</histogram>
</histograms>
</histogram-configuration>
"""


TEST_HISTOGRAM_WITH_MIXED_VARIANTS = """
<histogram-configuration>
<histograms>
<variants name="HistogramNameSize">
  <variant name=".medium" summary="medium"/>
  <variant name=".large" summary="large"/>
</variants>

<histogram name="HistogramName.{Color}{Size}" units="things"
    expires_after="2017-10-16">
  <owner>me@chromium.org</owner>
  <summary>
    This is a histogram for button of {Color} color and {Size} size.
  </summary>
  <token key="Color">
    <variant name="green">
      <owner>green@chromium.org</owner>
    </variant>
  </token>
  <token key="Size" variants="HistogramNameSize">
    <variant name="" summary="all"/>
  </token>
</histogram>
</histograms>
</histogram-configuration>
"""

class ExtractHistogramsTest(unittest.TestCase):

  def testExpiryFormat(self):
    chrome_histogram_pattern = """<histogram-configuration>

<histograms>

<histogram name="Histogram.Name" units="units" {}>
  <owner>SomeOne@google.com</owner>
  <summary>Summary</summary>
</histogram>

</histograms>

</histogram-configuration>
"""
    chrome_histogram_correct_expiry_date = chrome_histogram_pattern.format(
        'expires_after="2211-11-22"')
    _, errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_correct_expiry_date))
    self.assertFalse(errors)

    chrome_histogram_wrong_expiry_date_format = chrome_histogram_pattern.format(
        'expires_after="2211/11/22"')
    _, errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_wrong_expiry_date_format))
    self.assertTrue(errors)

    chrome_histogram_wrong_expiry_date_value = chrome_histogram_pattern.format(
        'expires_after="2211-22-11"')
    _, errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_wrong_expiry_date_value))
    self.assertTrue(errors)

    chrome_histogram_correct_expiry_milestone = chrome_histogram_pattern.format(
        'expires_after="M22"')
    _, errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_correct_expiry_milestone))
    self.assertFalse(errors)

    chrome_histogram_wrong_expiry_milestone = chrome_histogram_pattern.format(
        'expires_after="22"')
    _, errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_wrong_expiry_milestone))
    self.assertTrue(errors)

    chrome_histogram_wrong_expiry_milestone = chrome_histogram_pattern.format(
        'expires_after="MM22"')
    _, had_errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_wrong_expiry_milestone))
    self.assertTrue(errors)

    chrome_histogram_no_expiry = chrome_histogram_pattern.format('')
    _, had_errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_no_expiry))
    self.assertTrue(errors)

  def testExpiryDateExtraction(self):
    chrome_histogram_pattern = """<histogram-configuration>

<histograms>

<histogram name="Histogram.Name" units="units" {}>
  <owner>SomeOne@google.com</owner>
  <summary>Summary</summary>
</histogram>

</histograms>

</histogram-configuration>
"""
    date_str = '2211-11-22'
    chrome_histogram_correct_expiry_date = chrome_histogram_pattern.format(
        'expires_after="{}"'.format(date_str))
    histograms, _ = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_correct_expiry_date))
    histogram_content = histograms['Histogram.Name']
    self.assertIn('expires_after', histogram_content)
    self.assertEqual(date_str, histogram_content['expires_after'])

    milestone_str = 'M22'
    chrome_histogram_correct_expiry_milestone = chrome_histogram_pattern.format(
        'expires_after="{}"'.format(milestone_str))
    histograms, _ = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_correct_expiry_milestone))
    histogram_content = histograms['Histogram.Name']
    self.assertIn('expires_after', histogram_content)
    self.assertEqual(milestone_str, histogram_content['expires_after'])

    chrome_histogram_no_expiry = chrome_histogram_pattern.format('')
    histograms, _ = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(chrome_histogram_no_expiry))
    histogram_content = histograms['Histogram.Name']
    self.assertNotIn('expires_after', histogram_content)

  def testMultiParagraphSummary(self):
    multiple_paragraph_pattern = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
  <histogram name="MultiParagraphTest.Test1" units="units"
      expires_after="2019-01-01">
    <owner>chrome-metrics-team@google.com</owner>
    <summary>
      Sample description
      Sample description.
    </summary>
  </histogram>

  <histogram name="MultiParagraphTest.Test2" units="units"
      expires_after="2019-01-01">
    <owner>chrome-metrics-team@google.com</owner>
    <summary>
      Multi-paragraph sample description UI&gt;Browser.
      Words.

      Still multi-paragraph sample description.

      <!--Comments are allowed.-->

      Here.
    </summary>
  </histogram>
</histograms>
</histogram-configuration>
""")
    histograms, _ = extract_histograms._ExtractHistogramsFromXmlTree(
        multiple_paragraph_pattern, {})
    self.assertEqual(histograms['MultiParagraphTest.Test1']['summary'],
                     'Sample description Sample description.')
    self.assertEqual(
        histograms['MultiParagraphTest.Test2']['summary'],
        'Multi-paragraph sample description UI>Browser. Words.\n\n'
        'Still multi-paragraph sample description.\n\nHere.')

  def testComponentExtraction(self):
    """Checks that components are successfully extracted from histograms."""
    histogram = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
  <histogram name="Coffee" expires_after="2022-01-01" units="cups">
    <owner>histogram_owner@google.com</owner>
    <summary>An ode to coffee.</summary>
    <component>Liquid&gt;Hot</component>
    <component>Caffeine</component>
  </histogram>
</histograms>

<histogram_suffixes_list>
  <histogram_suffixes name="Brand" separator=".">
    <suffix name="Dunkies" label="The coffee is from Dunkin."/>
    <affected-histogram name="Coffee"/>
  </histogram_suffixes>
</histogram_suffixes_list>
</histogram-configuration>
""")
    histograms, _ = extract_histograms.ExtractHistogramsFromDom(histogram)
    self.assertEqual(histograms['Coffee']['components'],
                     ['Liquid>Hot', 'Caffeine'])
    self.assertEqual(histograms['Coffee.Dunkies']['components'],
                     ['Liquid>Hot', 'Caffeine'])

  def testNewHistogramWithoutSummary(self):
    histogram_without_summary = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" units="things" expires_after="2019-01-01">
   <owner>person@chromium.org</owner>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_without_summary, {})
    self.assertTrue(errors)

  def testNewHistogramWithEmptySummary(self):
    histogram_with_empty_summary = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" units="things" expires_after="2019-01-01">
   <owner>person@chromium.org</owner>
   <summary/>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_empty_summary, {})
    self.assertTrue(errors)

  def testNewHistogramWithoutEnumOrUnit(self):
    histogram_without_enum_or_unit = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" expires_after="2019-01-01">
  <owner>chrome-metrics-team@google.com</owner>
  <summary> This is a summary </summary>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_without_enum_or_unit, {})
    self.assertTrue(errors)

  def testNewHistogramWithEnumAndUnit(self):
    histogram_with_enum_and_unit = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" enum="MyEnumType" unit="things"
    expires_after="2019-01-01">
  <owner>chrome-metrics-team@google.com</owner>
  <summary> This is a summary </summary>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_enum_and_unit, {})
    self.assertTrue(errors)

  def testEmptyEnum(self):
    empty_enum = xml.dom.minidom.parseString("""
<histogram-configuration>
<enums>
  <enum name="MyEnumType">
    <summary>This is an empty enum</summary>
  </enum>
</enums>
</histogram-configuration>
""")
    _, errors = extract_histograms.ExtractEnumsFromXmlTree(empty_enum)
    self.assertTrue(errors)

  def testNewHistogramWithEnum(self):
    histogram_with_enum = xml.dom.minidom.parseString("""
<histogram-configuration>
<enums>
  <enum name="MyEnumType">
    <summary>This is an example enum type</summary>
    <int value="1" label="FIRST_VALUE">This is the first value.</int>
    <int value="2" label="SECOND_VALUE">This is the second value.</int>
  </enum>
</enums>

<histograms>
 <histogram name="Test.Histogram.Enum" enum="MyEnumType"
    expires_after="2019-01-01">
  <owner>chrome-metrics-team@google.com</owner>
  <summary> This is a summary </summary>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms.ExtractHistogramsFromDom(histogram_with_enum)
    self.assertFalse(errors)

  def testEnumWithDuplicateValues(self):
    bad_enum = xml.dom.minidom.parseString("""
<histogram-configuration>
<enums>
  <enum name="MyEnumType">
    <int value="1" label="FIRST_VALUE">This is the first value.</int>
    <int value="1" label="SECOND_VALUE">This is the second value.</int>
  </enum>
</enums>
</histogram-configuration>
""")
    _, errors = extract_histograms.ExtractEnumsFromXmlTree(bad_enum)
    self.assertTrue(errors)

  def testEnumWithDuplicateLabels(self):
    bad_enum = xml.dom.minidom.parseString("""
<histogram-configuration>
<enums>
  <enum name="MyEnumType">
    <int value="1" label="FIRST_VALUE">This is the first value.</int>
    <int value="2" label="FIRST_VALUE">This is the second value.</int>
  </enum>
</enums>
</histogram-configuration>
""")
    _, errors = extract_histograms.ExtractEnumsFromXmlTree(bad_enum)
    self.assertTrue(errors)

  def testNewHistogramWithUnits(self):
    histogram_with_units = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" units="units" expires_after="2019-01-01">
  <owner>chrome-metrics-team@google.com</owner>
  <summary> This is a summary </summary>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_units, {})
    self.assertFalse(errors)

  def testNewHistogramWithEmptyOwnerTag(self):
    histogram_with_empty_owner_tag = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" units="things" expires_after="2019-01-01">
  <owner></owner>
  <summary> This is a summary </summary>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_empty_owner_tag, {})
    self.assertTrue(errors)

  def testNewHistogramWithoutOwnerTag(self):
    histogram_without_owner_tag = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" units="things" expires_after="2019-01-01">
  <summary> This is a summary </summary>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_without_owner_tag, {})
    self.assertTrue(errors)

  def testNewHistogramWithCommaSeparatedOwners(self):
    histogram_with_comma_separated_owners = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" units="things" expires_after="2019-01-01">
  <owner>cait@chromium.org, paul@chromium.org</owner>
  <summary> This is a summary </summary>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_comma_separated_owners, {})
    self.assertTrue(errors)

  def testNewHistogramWithInvalidOwner(self):
    histogram_with_invalid_owner = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" units="things" expires_after="2019-01-01">
  <owner>sarah</owner>
  <summary> This is a summary </summary>
 </histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_invalid_owner, {})
    self.assertTrue(errors)

  def testHistogramWithEscapeCharacters(self):
    histogram_with_owner_placeholder = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
 <histogram name="Test.Histogram" units="things" expires_after="2019-01-01">
  <owner>histogram_owner@google.com</owner>
  <summary>This is a summary with &amp; and &quot; and &apos;</summary>
 </histogram>
</histograms>
</histogram-configuration>
""")
    hists, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_owner_placeholder, {})
    self.assertFalse(errors)
    self.assertIn('Test.Histogram', hists)
    self.assertIn('summary', hists['Test.Histogram'])
    self.assertEqual('This is a summary with & and " and \'',
                     hists['Test.Histogram']['summary'])

  def testNewSuffixWithoutLabel(self):
    suffix_without_label = xml.dom.minidom.parseString("""
<histogram-configuration>
<histogram_suffixes_list>
  <histogram_suffixes name="Suffixes" separator=".">
    <suffix base="true" name="BaseSuffix"/>
  </histogram_suffixes>
</histogram_suffixes_list>
</histogram-configuration>
""")
    _, errors = extract_histograms.ExtractHistogramsFromDom(
        suffix_without_label)
    self.assertTrue(errors)

  def testNewSuffixWithLabel(self):
    suffix_with_label = xml.dom.minidom.parseString("""
<histogram-configuration>
<histogram_suffixes_list>
  <histogram_suffixes name="Suffixes" separator=".">
    <suffix base="true" name="BaseSuffix" label="Base"/>
  </histogram_suffixes>
</histogram_suffixes_list>
</histogram-configuration>
""")
    errors = extract_histograms._UpdateHistogramsWithSuffixes(
        suffix_with_label, {})
    self.assertFalse(errors)

  @parameterized.expand([
      ('InlineTokens', TEST_HISTOGRAM_WITH_TOKENS),
      ('InlineTokenAndOutOfLineVariants', TEST_HISTOGRAM_WITH_VARIANTS),
      ('ImplicitAndOutOfLineVariants', TEST_HISTOGRAM_WITH_IMPLICIT_VARIANTS),
      ('MixedVariants', TEST_HISTOGRAM_WITH_MIXED_VARIANTS),
  ])
  def testUpdateNameWithTokens(self, _, input_xml):
    histogram_with_token = xml.dom.minidom.parseString(input_xml)
    histograms_dict, _ = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_token, {})
    histograms_dict, _ = extract_histograms._UpdateHistogramsWithTokens(
        histograms_dict)
    self.assertIn('HistogramName.green.medium', histograms_dict)
    self.assertIn('HistogramName.green.large', histograms_dict)
    self.assertIn('HistogramName.green', histograms_dict)
    self.assertNotIn('HistogramName{Color}{Size}', histograms_dict)

    # Make sure generated histograms do not have tokens.
    self.assertNotIn('tokens', histograms_dict['HistogramName.green.large'])

  @parameterized.expand([
      ('InlineTokens', TEST_HISTOGRAM_WITH_TOKENS),
      ('InlineTokenAndOutOfLineVariants', TEST_HISTOGRAM_WITH_VARIANTS),
      ('ImplicitAndOutOfLineVariants', TEST_HISTOGRAM_WITH_IMPLICIT_VARIANTS),
      ('MixedVariants', TEST_HISTOGRAM_WITH_MIXED_VARIANTS),
  ])
  def testUpdateSummaryWithTokens(self, _, input_xml):
    histogram_with_token = xml.dom.minidom.parseString(input_xml)
    histograms_dict, _ = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_token, {})
    histograms_dict, _ = extract_histograms._UpdateHistogramsWithTokens(
        histograms_dict)
    # Use the variant's name to format the summary when the variant's summary
    # attribute is omitted.
    self.assertEqual(
        'This is a histogram for button of green color and medium size.',
        histograms_dict['HistogramName.green.medium']['summary'])
    self.assertEqual(
        'This is a histogram for button of green color and large size.',
        histograms_dict['HistogramName.green.large']['summary'])
    self.assertEqual(
        'This is a histogram for button of green color and all size.',
        histograms_dict['HistogramName.green']['summary'])

  @parameterized.expand([
      ('InlineTokens', TEST_HISTOGRAM_WITH_TOKENS),
      ('InlineTokenAndOutOfLineVariants', TEST_HISTOGRAM_WITH_VARIANTS),
      ('ImplicitAndOutOfLineVariants', TEST_HISTOGRAM_WITH_IMPLICIT_VARIANTS),
      ('MixedVariants', TEST_HISTOGRAM_WITH_MIXED_VARIANTS),
  ])
  def testUpdateWithTokenOwner(self, _, input_xml):
    histogram_with_token = xml.dom.minidom.parseString(input_xml)
    histograms_dict, _ = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_token, {})
    histograms_dict, _ = extract_histograms._UpdateHistogramsWithTokens(
        histograms_dict)

    self.assertEqual(['green@chromium.org'],
                     histograms_dict['HistogramName.green.medium']['owners'])
    self.assertEqual(['green@chromium.org'],
                     histograms_dict['HistogramName.green.large']['owners'])
    self.assertEqual(['green@chromium.org'],
                     histograms_dict['HistogramName.green']['owners'])

  @parameterized.expand([
      ('InlineTokens', TEST_HISTOGRAM_TOKENS_DUPLICATE),
      ('InlineTokenAndOutOfLineVariants', TEST_HISTOGRAM_VARIANTS_DUPLICATE),
  ])
  def testUpdateNameDuplicateVariant(self, _, input_xml):
    """Tests that if duplicate names are generated due to multiple tokens
    having the same variant and empty string variant, an error is reported."""
    histogram_with_duplicate_variant = xml.dom.minidom.parseString(input_xml)
    histograms_dict, _ = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_with_duplicate_variant, {})
    _, errors = extract_histograms._UpdateHistogramsWithTokens(histograms_dict)
    self.assertTrue(errors)

  def testVariantsNotExists(self):
    histogram_without_corresponding_variants = xml.dom.minidom.parseString("""
<histogram-configuration>
<histograms>
<histogram name="Histogram{Color}{SizeNone}" units="things"
    expires_after="2017-10-16">
  <owner>me@chromium.org</owner>
  <summary>
    This is a histogram for button of {Color} color and {SizeNone} size.
  </summary>
  <token key="Color">
    <variant name="" summary="all"/>
    <variant name=".red" summary="red"/>
    <variant name=".green" summary="green"/>
  </token>
  <token key="SizeNone" variants="HistogramNameSize"/>
</histogram>
</histograms>
</histogram-configuration>
""")
    _, errors = extract_histograms._ExtractHistogramsFromXmlTree(
        histogram_without_corresponding_variants, {})
    self.assertTrue(errors)

  def testSuffixCanExtendPatternedHistograms(self):
    patterned_suffix = ("""
        <histogram-configuration>
        <histograms>
          <histogram name="Test{Version}" units="things"
            expires_after="2017-10-16">
            <owner>chrome-metrics-team@google.com</owner>
            <summary>
              Sample description.
            </summary>
            <token key="Version">
              <variant name=".First"/>
              <variant name=".Last"/>
            </token>
          </histogram>
        </histograms>
        <histogram_suffixes_list>
          <histogram_suffixes name="ExtendPatternedHist" separator=".">
            <suffix name="Found" label="Extending patterned histograms."/>
            <affected-histogram name="Test.First"/>
            <affected-histogram name="Test.Last"/>
          </histogram_suffixes>
        </histogram_suffixes_list>
        </histogram-configuration>""")
    # Only when the histogram is first extended by the token, can the
    # histogram_suffixes find those affected histograms.
    histograms_dict, errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(patterned_suffix))
    self.assertFalse(errors)
    self.assertIn('Test.First.Found', histograms_dict)
    self.assertIn('Test.Last.Found', histograms_dict)

  def testExtractImprovementDirection(self):
    histogram_name = 'Histogram.With.InterpretationTag'
    config = """
<histogram-configuration>

<histograms>

<histogram name="{histogram_name}" expires_after="M100" units="units">
  <owner>owner@chromium.org</owner>
  {improvement_tag}
  <summary>The improvement tag says a higher value is good!</summary>
</histogram>

</histograms>

</histogram-configuration>"""

    improvement_tag_good = '<improvement direction="HIGHER_IS_BETTER"/>'
    improvement_tag_bad = '<improvement>HIGHER_IS_BETTER</improvement>'

    config_good = config.format(histogram_name=histogram_name,
                                improvement_tag=improvement_tag_good)
    config_bad = config.format(histogram_name=histogram_name,
                               improvement_tag=improvement_tag_bad)

    histograms_dict, errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(config_good))
    self.assertFalse(errors)
    self.assertIn(histogram_name, histograms_dict)
    self.assertIn('improvement', histograms_dict[histogram_name])
    self.assertEqual(
        histogram_configuration_model.IMPROVEMENT_DIRECTION_HIGHER_IS_BETTER,
        histograms_dict[histogram_name]['improvement'])

    histograms_dict, errors = extract_histograms.ExtractHistogramsFromDom(
        xml.dom.minidom.parseString(config_bad))
    self.assertTrue(errors)
    self.assertNotIn('improvement', histograms_dict[histogram_name])


if __name__ == "__main__":
  logging.basicConfig(level=logging.ERROR + 1)
  unittest.main()