changeset 35190:bd8875b6473c

run-tests: mechanism to report exceptions during test execution Sometimes when running tests you introduce a ton of exceptions. The most extreme example of this is running Mercurial with Python 3, which currently spews thousands of exceptions when running the test harness. This commit adds an opt-in feature to run-tests.py to aggregate exceptions encountered by `hg` when running tests. When --exceptions is used, the test harness enables the "logexceptions" extension in the test environment. This extension wraps the Mercurial function to handle exceptions and writes information about the exception to a random filename in a directory defined by the test harness via an environment variable. At the end of the test harness, these files are parsed, aggregated, and a list of all unique Mercurial frames triggering exceptions is printed in order of frequency. This feature is intended to aid Python 3 development. I've only really tested it on Python 3. There is no shortage of improvements that could be made. e.g. we could write a separate file containing the exception report - maybe even an HTML report. We also don't capture which tests demonstrate the exceptions, so there's no turnkey way to test whether a code change made an exception disappear. Perfect is the enemy of good. I think the current patch is useful enough to land. Whoever uses it can send patches to imprve its usefulness. Differential Revision: https://phab.mercurial-scm.org/D1477
author Gregory Szorc <gregory.szorc@gmail.com>
date Mon, 20 Nov 2017 23:02:32 -0800
parents 073843b5e353
children a1d2fc32bb99
files .hgignore tests/logexceptions.py tests/run-tests.py
diffstat 3 files changed, 125 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/.hgignore	Mon Nov 20 21:26:11 2017 -0800
+++ b/.hgignore	Mon Nov 20 23:02:32 2017 -0800
@@ -24,6 +24,7 @@
 tests/.hypothesis
 tests/hypothesis-generated
 tests/annotated
+tests/exceptions
 tests/*.err
 tests/htmlcov
 build
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/logexceptions.py	Mon Nov 20 23:02:32 2017 -0800
@@ -0,0 +1,73 @@
+# logexceptions.py - Write files containing info about Mercurial exceptions
+#
+# Copyright 2017 Matt Mackall <mpm@selenic.com>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+from __future__ import absolute_import
+
+import inspect
+import os
+import sys
+import traceback
+import uuid
+
+from mercurial import (
+    dispatch,
+    extensions,
+)
+
+def handleexception(orig, ui):
+    res = orig(ui)
+
+    if not ui.environ.get(b'HGEXCEPTIONSDIR'):
+        return res
+
+    dest = os.path.join(ui.environ[b'HGEXCEPTIONSDIR'],
+                        str(uuid.uuid4()).encode('ascii'))
+
+    exc_type, exc_value, exc_tb = sys.exc_info()
+
+    stack = []
+    tb = exc_tb
+    while tb:
+        stack.append(tb)
+        tb = tb.tb_next
+    stack.reverse()
+
+    hgframe = 'unknown'
+    hgline = 'unknown'
+
+    # Find the first Mercurial frame in the stack.
+    for tb in stack:
+        mod = inspect.getmodule(tb)
+        if not mod.__name__.startswith(('hg', 'mercurial')):
+            continue
+
+        frame = tb.tb_frame
+
+        try:
+            with open(inspect.getsourcefile(tb), 'r') as fh:
+                hgline = fh.readlines()[frame.f_lineno - 1].strip()
+        except (IndexError, OSError):
+            pass
+
+        hgframe = '%s:%d' % (frame.f_code.co_filename, frame.f_lineno)
+        break
+
+    primary = traceback.extract_tb(exc_tb)[-1]
+    primaryframe = '%s:%d' % (primary.filename, primary.lineno)
+
+    with open(dest, 'wb') as fh:
+        parts = [
+            str(exc_value),
+            primaryframe,
+            hgframe,
+            hgline,
+        ]
+        fh.write(b'\0'.join(p.encode('utf-8', 'replace') for p in parts))
+
+def extsetup(ui):
+    extensions.wrapfunction(dispatch, 'handlecommandexception',
+                            handleexception)
--- a/tests/run-tests.py	Mon Nov 20 21:26:11 2017 -0800
+++ b/tests/run-tests.py	Mon Nov 20 23:02:32 2017 -0800
@@ -46,6 +46,7 @@
 from __future__ import absolute_import, print_function
 
 import argparse
+import collections
 import difflib
 import distutils.version as version
 import errno
@@ -373,7 +374,7 @@
         help="install and use chg wrapper in place of hg")
     hgconf.add_argument("--compiler",
         help="compiler to build with")
-    hgconf.add_argument('--extra-config-opt', action="append",
+    hgconf.add_argument('--extra-config-opt', action="append", default=[],
         help='set the given config opt in the test hgrc')
     hgconf.add_argument("-l", "--local", action="store_true",
         help="shortcut for --with-hg=<testdir>/../hg, "
@@ -404,6 +405,8 @@
         help="colorisation: always|auto|never (default: auto)")
     reporting.add_argument("-c", "--cover", action="store_true",
         help="print a test coverage report")
+    reporting.add_argument('--exceptions', action='store_true',
+        help='log all exceptions and generate an exception report')
     reporting.add_argument("-H", "--htmlcov", action="store_true",
         help="create an HTML report of the coverage of the files")
     reporting.add_argument("--json", action="store_true",
@@ -2115,6 +2118,18 @@
                     os.environ['PYTHONHASHSEED'])
             if self._runner.options.time:
                 self.printtimes(result.times)
+
+            if self._runner.options.exceptions:
+                exceptions = aggregateexceptions(
+                    os.path.join(self._runner._outputdir, b'exceptions'))
+                total = sum(exceptions.values())
+
+                self.stream.writeln('Exceptions Report:')
+                self.stream.writeln('%d total from %d frames' %
+                                    (total, len(exceptions)))
+                for (frame, line, exc), count in exceptions.most_common():
+                    self.stream.writeln('%d\t%s: %s' % (count, frame, exc))
+
             self.stream.flush()
 
         return result
@@ -2501,6 +2516,23 @@
 
         self._coveragefile = os.path.join(self._testdir, b'.coverage')
 
+        if self.options.exceptions:
+            exceptionsdir = os.path.join(self._outputdir, b'exceptions')
+            try:
+                os.makedirs(exceptionsdir)
+            except OSError as e:
+                if e.errno != errno.EEXIST:
+                    raise
+
+            # Remove all existing exception reports.
+            for f in os.listdir(exceptionsdir):
+                os.unlink(os.path.join(exceptionsdir, f))
+
+            osenvironb[b'HGEXCEPTIONSDIR'] = exceptionsdir
+            logexceptions = os.path.join(self._testdir, b'logexceptions.py')
+            self.options.extra_config_opt.append(
+                'extensions.logexceptions=%s' % logexceptions.decode('utf-8'))
+
         vlog("# Using TESTDIR", self._testdir)
         vlog("# Using RUNTESTDIR", osenvironb[b'RUNTESTDIR'])
         vlog("# Using HGTMP", self._hgtmp)
@@ -2953,6 +2985,24 @@
                 print("WARNING: Did not find prerequisite tool: %s " %
                       p.decode("utf-8"))
 
+def aggregateexceptions(path):
+    exceptions = collections.Counter()
+
+    for f in os.listdir(path):
+        with open(os.path.join(path, f), 'rb') as fh:
+            data = fh.read().split(b'\0')
+            if len(data) != 4:
+                continue
+
+            exc, mainframe, hgframe, hgline = data
+            exc = exc.decode('utf-8')
+            mainframe = mainframe.decode('utf-8')
+            hgframe = hgframe.decode('utf-8')
+            hgline = hgline.decode('utf-8')
+            exceptions[(hgframe, hgline, exc)] += 1
+
+    return exceptions
+
 if __name__ == '__main__':
     runner = TestRunner()