Capture qutebrowser/httpbin output separately.

When using print and relying on pytest to capture it as stdout, we ran into
this pytest/pytest-qt issue:

https://github.com/pytest-dev/pytest-qt/issues/113

Now we use our own capturing mechanism instead, which also means we get nicer
output.

Fixes #1122.

tests/integration/conftest.py

@@ -23,3 +23,4 @@
 
 from webserver import httpbin, httpbin_after_test
 from quteprocess import quteproc_process, quteproc
+from testprocess import pytest_runtest_makereport

tests/integration/quteprocess.py

@@ -174,7 +174,7 @@ class QuteProc(testprocess.Process):
         # pylint: disable=no-member
         if (log_line.loglevel in ['INFO', 'WARNING', 'ERROR'] or
                 pytest.config.getoption('--verbose')):
-            print(line)
+            self._log(line)
 
         start_okay_message_load = (
             "load status for <qutebrowser.browser.webview.WebView tab_id=0 "
@@ -306,7 +306,7 @@ class QuteProc(testprocess.Process):
             with open(session, encoding='utf-8') as f:
                 data = f.read()
 
-        print(data)
+        self._log(data)
         return yaml.load(data)
 
     def get_content(self, plain=True):
@@ -341,8 +341,9 @@ def quteproc_process(qapp, httpbin, request):
 
 
 @pytest.yield_fixture
-def quteproc(quteproc_process, httpbin):
+def quteproc(quteproc_process, httpbin, request):
     """Per-test qutebrowser fixture which uses the per-file process."""
+    request.node._quteproc_log = quteproc_process.captured_log
     quteproc_process.before_test()
     yield quteproc_process
     quteproc_process.after_test()

tests/integration/testprocess.py

@@ -23,6 +23,7 @@ import re
 import os
 import time
 
+import pytest
 import pytestqt.plugin
 from PyQt5.QtCore import pyqtSlot, pyqtSignal, QProcess, QObject, QElapsedTimer
 from PyQt5.QtTest import QSignalSpy
@@ -71,6 +72,28 @@ class Line:
         return '{}({!r})'.format(self.__class__.__name__, self.data)
 
 
+@pytest.hookimpl(hookwrapper=True)
+def pytest_runtest_makereport(item, call):
+    """Add qutebrowser/httpbin sections to captured output if a test failed."""
+    outcome = yield
+    if call.when != 'call':
+        return
+    report = outcome.get_result()
+
+    if report.passed:
+        return
+
+    quteproc_log = getattr(item, '_quteproc_log', None)
+    httpbin_log = getattr(item, '_httpbin_log', None)
+
+    if quteproc_log is not None:
+        report.longrepr.addsection("qutebrowser output",
+                                   '\n'.join(quteproc_log))
+    if httpbin_log is not None:
+        report.longrepr.addsection("httpbin output",
+                                   '\n'.join(httpbin_log))
+
+
 class Process(QObject):
 
     """Abstraction over a running test subprocess process.
@@ -93,11 +116,16 @@ class Process(QObject):
 
     def __init__(self, parent=None):
         super().__init__(parent)
+        self.captured_log = []
         self._invalid = []
         self._data = []
         self.proc = QProcess()
         self.proc.setReadChannel(QProcess.StandardError)
 
+    def _log(self, line):
+        """Add the given line to the captured log output."""
+        self.captured_log.append(line)
+
     def _parse_line(self, line):
         """Parse the given line from the log.
 
@@ -146,12 +174,12 @@ class Process(QObject):
                 parsed = self._parse_line(line)
             except InvalidLine:
                 self._invalid.append(line)
-                print("INVALID: {}".format(line))
+                self._log("INVALID: {}".format(line))
                 continue
 
             if parsed is None:
                 if self._invalid:
-                    print("IGNORED: {}".format(line))
+                    self._log("IGNORED: {}".format(line))
             else:
                 self._data.append(parsed)
                 self.new_data.emit(parsed)

tests/integration/webserver.py

@@ -129,7 +129,7 @@ class HTTPBin(testprocess.Process):
         return [r for r in requests if r.path != '/favicon.ico']
 
     def _parse_line(self, line):
-        print(line)
+        self._log(line)
         if line == (' * Running on http://127.0.0.1:{}/ (Press CTRL+C to '
                     'quit)'.format(self.port)):
             self.ready.emit()
@@ -164,7 +164,8 @@ def httpbin(qapp):
 
 
 @pytest.yield_fixture(autouse=True)
-def httpbin_after_test(httpbin):
+def httpbin_after_test(httpbin, request):
     """Fixture to clean httpbin request list after each test."""
+    request.node._httpbin_log = httpbin.captured_log
     yield
     httpbin.after_test()