tests: implement coverage reporting

  - move the logic of uploading to WebDAV server here instead of the
 generated bin/runUnitTest wrapper
  - run a new `coverage_report` which will
    - download all coverage data from WebDAV server
    - combine the data
    - run html report, saved in log folder
    - print text output in the text output.

This `coverage_report` test waits for other tests to finish uploading
data, we could extend test node distributor to distribute this test at
the end.

product/ERP5Type/tests/coverage_report.py

+"""Manage coverage reporting for ERP5 test runner.
+
+This file is used in two contexts:
+ - at the end of every test, this module is imported and `upload` is called to upload
+ coverage data to WebDAV server.
+ - this is ran as a unittest at the end, to download all coverage data from the WebDAV
+ server and run coverage report.
+"""
+
+from __future__ import print_function
+import json
+import logging
+import os
+import sys
+import time
+import unittest
+
+import coverage
+import requests
+import six
+import uritemplate
+from six.moves.urllib.parse import urlparse
+
+from Products.ERP5Type.tests.runUnitTest import log_directory
+
+
+def _get_auth_list_from_url(parsed_url):
+  if parsed_url.username:
+    # try Digest and Basic authentication
+    return (
+      requests.auth.HTTPDigestAuth(parsed_url.username, parsed_url.password),
+      requests.auth.HTTPBasicAuth(parsed_url.username, parsed_url.password),
+    )
+  return (None,)
+
+
+def _expand_uri_template(url, **kw):
+  # Environment variables are set in product/ERP5Type/tests/runTestSuite.py
+  kw.setdefault(
+    'test_result_id',
+    os.environ.get('ERP5_TEST_RESULT_ID', 'unknown_test_result_id'),
+  )
+  kw.setdefault(
+    'test_result_revision',
+    os.environ.get('ERP5_TEST_RESULT_REVISION', 'unknown_test_result_revision'),
+  )
+  return uritemplate.URITemplate(url).expand(**kw)
+
+
+def upload(filename, upload_url_template, test_name):
+  upload_url = _expand_uri_template(upload_url_template, test_name=test_name)
+  parsed_url = urlparse(upload_url)
+  hostname = parsed_url.hostname
+  with requests.Session() as session:
+    for retry in range(5):
+      for auth in _get_auth_list_from_url(parsed_url):
+        with open(filename, 'rb') as f:
+          try:
+            resp = session.put(upload_url, data=f, auth=auth, timeout=30)
+          except requests.exceptions.RequestException as e:
+            error = e
+          else:
+            if resp.ok:
+              print('Uploaded coverage data to {hostname}'.format(hostname=hostname))
+              return
+            error = resp.status_code
+        if (
+          retry
+        ):  # don't print error on first time, because `auth` might be wrong class
+          print(
+            'Error {error} uploading coverage data to {hostname} with {auth.__class__.__name__}'.format(
+              error=error, hostname=hostname, auth=auth
+            )
+          )
+        time.sleep(retry)
+
+
+class CoverageReport(unittest.TestCase):
+  def setUp(self):
+    self._logger = logging.getLogger(__name__)
+    self._coverage_process = coverage.Coverage.current()
+    self._coverage_process.stop()
+
+    with open(os.environ['ERP5_TEST_RUNNER_CONFIGURATION']) as f:
+      self._test_runner_configuration = json.load(f)
+
+    downloaded_coverage_path_set = self._download_coverage_data()
+    self._coverage_process.combine(
+      data_paths=downloaded_coverage_path_set,
+    )
+    self._coverage_process.save()
+
+  def _download_coverage_data(self):
+    downloaded_coverage_path_set = set()
+    download_url_template = self._test_runner_configuration['coverage']['upload-url']
+    assert download_url_template
+
+    coverage_data_directory = os.path.join(log_directory, 'coverage_data')
+    if not os.path.exists(coverage_data_directory):
+      os.makedirs(coverage_data_directory)
+
+    to_download = set(
+      json.loads(
+        # ERP5_TEST_TEST_LIST is set in product/ERP5Type/tests/runTestSuite.py
+        # it contains the list of tests as returned by ERP5TypeTestSuite.getTestList
+        os.environ['ERP5_TEST_TEST_LIST'],
+      )
+    )
+
+    with requests.Session() as session:
+      while to_download:
+        for test_name in list(to_download):
+          test_file_name = test_name.replace(':', '_')
+          download_destination = os.path.join(
+            coverage_data_directory,
+            '{test_name}.coverage.sqlite3'.format(test_name=test_file_name),
+          )
+          if os.path.exists(download_destination):
+            downloaded_coverage_path_set.add(download_destination)
+            to_download.remove(test_name)
+            continue
+          download_url = _expand_uri_template(
+            download_url_template, test_name=test_file_name
+          )
+          parsed_url = urlparse(download_url)
+          hostname = parsed_url.hostname
+          for auth in _get_auth_list_from_url(parsed_url):
+            try:
+              resp = session.get(download_url, auth=auth, timeout=30)
+            except requests.exceptions.RequestException:
+              self._logger.exception('Error during request, retrying')
+              continue
+            if resp.ok:
+              with open(download_destination + '.tmp', 'wb') as f:
+                f.write(resp.content)
+              os.rename(download_destination + '.tmp', download_destination)
+              self._logger.info(
+                'Downloaded %s coverage data from %s',
+                test_name,
+                hostname,
+              )
+              break
+            self._logger.critical(
+              'Error %s downloading coverage data for %s from %s with %s, retrying',
+              resp.status_code,
+              test_name,
+              hostname,
+              auth.__class__.__name__,
+            )
+            time.sleep(60 if resp.status_code == 404 else 5)
+    return downloaded_coverage_path_set
+
+  def test_coverage_report(self):
+    # reports must run from the root of slapos software, because we recorded
+    # relative paths.
+    os.chdir(
+      os.path.dirname(
+        os.path.dirname(
+          os.path.dirname(
+            os.path.dirname(
+              os.path.dirname(
+                os.path.dirname(__file__),
+              )
+            )
+          )
+        )
+      )
+    )
+
+    self._coverage_process.html_report(
+      directory=os.path.join(log_directory, 'html_report'),
+      show_contexts=True,
+      # We ignore errors because some tests execute code that does not exist on disk, causing
+      # errors like this:
+      #   NoSource: No source for code: 'parts/erp5/product/ERP5/Document/UnitTest.py'.
+      #   Aborting report output, consider using -i.
+      ignore_errors=True,
+    )
+
+    if six.PY3:
+      self._coverage_process.lcov_report(
+        outfile=os.path.join(log_directory, 'coverage.lcov'),
+        ignore_errors=True,
+      )
+
+    total_coverage = self._coverage_process.report(
+      file=sys.stderr,
+      skip_covered=True,
+      skip_empty=True,
+      ignore_errors=True,
+    )
+    self.assertGreater(
+      total_coverage,
+      self._test_runner_configuration['coverage'].get('fail-under', 50),
+    )

product/ERP5Type/tests/runTestSuite.py

 from __future__ import absolute_import
 from __future__ import print_function
-import argparse, sys, os, textwrap
+import argparse, json, sys, os, textwrap
 from erp5.util import taskdistribution
 
 # XXX: This import is required, just to populate sys.modules['test_suite'].
@@ -127,6 +127,9 @@ def main():
   # sanity check
   assert len(args.zserver_address_list) == len(args.zserver_frontend_url_list)
 
+  with open(os.environ['ERP5_TEST_RUNNER_CONFIGURATION']) as f:
+    test_runner_configuration = json.load(f)
+
   suite = makeSuite(test_suite=args.test_suite,
                     node_quantity=args.node_quantity,
                     revision=revision,
@@ -137,12 +140,17 @@ def main():
                     firefox_bin=args.firefox_bin,
                     xvfb_bin=args.xvfb_bin,
                     log_directory=args.log_directory)
-  test_result = master.createTestResult(revision, suite.getTestList(),
+  test_list = suite.getTestList()
+  test_list_json = json.dumps(test_list)
+  if test_runner_configuration.get('coverage', {}).get('enabled'):
+    test_list.append("coverage_report")
+  test_result = master.createTestResult(revision, test_list,
     args.test_node_title, suite.allow_restart, test_suite_title,
     args.project_title)
   if test_result is not None:
     os.environ['ERP5_TEST_RESULT_REVISION'] = test_result.revision
     os.environ['ERP5_TEST_RESULT_ID'] = (test_result.test_result_path or '').split('/')[-1]
+    os.environ['ERP5_TEST_TEST_LIST'] = test_list_json
 
     assert revision == test_result.revision, (revision, test_result.revision)
     while suite.acquire():