Merge master into features (#5874)

Merge master into features

AUTHORS

@@ -176,6 +176,7 @@ mbyt
 Michael Aquilina
 Michael Birtwell
 Michael Droettboom
+Michael Goerz
 Michael Seifert
 Michal Wajszczuk
 Mihai Capotă

changelog/1682.deprecation.rst

@@ -0,0 +1,2 @@
+Passing arguments to pytest.fixture() as positional arguments is deprecated - pass them
+as a keyword argument instead.

changelog/1682.feature.rst

@@ -0,0 +1,3 @@
+The ``scope`` parameter of ``@pytest.fixture`` can now be a callable that receives
+the fixture name and the ``config`` object as keyword-only parameters.
+See `the docs <https://docs.pytest.org/en/fixture.html#dynamic-scope>`__ for more information.

changelog/5056.trivial.rst

@@ -0,0 +1 @@
+The HelpFormatter uses ``py.io.get_terminal_width`` for better width detection.

changelog/5764.feature.rst

@@ -0,0 +1 @@
+New behavior of the ``--pastebin`` option: failures to connect to the pastebin server are reported, without failing the pytest run

changelog/5806.bugfix.rst

@@ -0,0 +1 @@
+Fix "lexer" being used when uploading to bpaste.net from ``--pastebin`` to "text".

doc/en/example/costlysetup/conftest.py

@@ -1,7 +1,7 @@
 import pytest
 
 
-@pytest.fixture("session")
+@pytest.fixture(scope="session")
 def setup(request):
     setup = CostlySetup()
     yield setup

doc/en/fixture.rst

@@ -301,6 +301,32 @@ are finalized when the last test of a *package* finishes.
     Use this new feature sparingly and please make sure to report any issues you find.
 
 
+Dynamic scope
+^^^^^^^^^^^^^
+
+In some cases, you might want to change the scope of the fixture without changing the code.
+To do that, pass a callable to ``scope``. The callable must return a string with a valid scope
+and will be executed only once - during the fixture definition. It will be called with two
+keyword arguments - ``fixture_name`` as a string and ``config`` with a configuration object.
+
+This can be especially useful when dealing with fixtures that need time for setup, like spawning
+a docker container. You can use the command-line argument to control the scope of the spawned
+containers for different environments. See the example below.
+
+.. code-block:: python
+
+    def determine_scope(fixture_name, config):
+        if config.getoption("--keep-containers"):
+            return "session"
+        return "function"
+
+
+    @pytest.fixture(scope=determine_scope)
+    def docker_container():
+        yield spawn_container()
+
+
+
 Order: Higher-scoped fixtures are instantiated first
 ----------------------------------------------------
 

src/_pytest/_code/code.py

@@ -5,10 +5,15 @@ import traceback
 from inspect import CO_VARARGS
 from inspect import CO_VARKEYWORDS
 from traceback import format_exception_only
+from types import CodeType
 from types import TracebackType
+from typing import Any
+from typing import Dict
 from typing import Generic
+from typing import List
 from typing import Optional
 from typing import Pattern
+from typing import Set
 from typing import Tuple
 from typing import TypeVar
 from typing import Union
@@ -29,7 +34,7 @@ if False:  # TYPE_CHECKING
 class Code:
     """ wrapper around Python code objects """
 
-    def __init__(self, rawcode):
+    def __init__(self, rawcode) -> None:
         if not hasattr(rawcode, "co_filename"):
             rawcode = getrawcode(rawcode)
         try:
@@ -38,7 +43,7 @@ class Code:
             self.name = rawcode.co_name
         except AttributeError:
             raise TypeError("not a code object: {!r}".format(rawcode))
-        self.raw = rawcode
+        self.raw = rawcode  # type: CodeType
 
     def __eq__(self, other):
         return self.raw == other.raw
@@ -351,7 +356,7 @@ class Traceback(list):
         """ return the index of the frame/TracebackEntry where recursion
             originates if appropriate, None if no recursion occurred
         """
-        cache = {}
+        cache = {}  # type: Dict[Tuple[Any, int, int], List[Dict[str, Any]]]
         for i, entry in enumerate(self):
             # id for the code.raw is needed to work around
             # the strange metaprogramming in the decorator lib from pypi
@@ -650,7 +655,7 @@ class FormattedExcinfo:
                 args.append((argname, saferepr(argvalue)))
             return ReprFuncArgs(args)
 
-    def get_source(self, source, line_index=-1, excinfo=None, short=False):
+    def get_source(self, source, line_index=-1, excinfo=None, short=False) -> List[str]:
         """ return formatted and marked up source lines. """
         import _pytest._code
 
@@ -722,7 +727,7 @@ class FormattedExcinfo:
         else:
             line_index = entry.lineno - entry.getfirstlinesource()
 
-        lines = []
+        lines = []  # type: List[str]
         style = entry._repr_style
         if style is None:
             style = self.style
@@ -799,7 +804,7 @@ class FormattedExcinfo:
                 exc_msg=str(e),
                 max_frames=max_frames,
                 total=len(traceback),
-            )
+            )  # type: Optional[str]
             traceback = traceback[:max_frames] + traceback[-max_frames:]
         else:
             if recursionindex is not None:
@@ -812,10 +817,12 @@ class FormattedExcinfo:
 
     def repr_excinfo(self, excinfo):
 
-        repr_chain = []
+        repr_chain = (
+            []
+        )  # type: List[Tuple[ReprTraceback, Optional[ReprFileLocation], Optional[str]]]
         e = excinfo.value
         descr = None
-        seen = set()
+        seen = set()  # type: Set[int]
         while e is not None and id(e) not in seen:
             seen.add(id(e))
             if excinfo:
@@ -868,8 +875,8 @@ class TerminalRepr:
 
 
 class ExceptionRepr(TerminalRepr):
-    def __init__(self):
+    def __init__(self) -> None:
-        self.sections = []
+        self.sections = []  # type: List[Tuple[str, str, str]]
 
     def addsection(self, name, content, sep="-"):
         self.sections.append((name, content, sep))

src/_pytest/_code/source.py

@@ -7,6 +7,7 @@ import tokenize
 import warnings
 from ast import PyCF_ONLY_AST as _AST_FLAG
 from bisect import bisect_right
+from typing import List
 
 import py
 
@@ -19,11 +20,11 @@ class Source:
     _compilecounter = 0
 
     def __init__(self, *parts, **kwargs):
-        self.lines = lines = []
+        self.lines = lines = []  # type: List[str]
         de = kwargs.get("deindent", True)
         for part in parts:
             if not part:
-                partlines = []
+                partlines = []  # type: List[str]
             elif isinstance(part, Source):
                 partlines = part.lines
             elif isinstance(part, (tuple, list)):
@@ -157,8 +158,7 @@ class Source:
         source = "\n".join(self.lines) + "\n"
         try:
             co = compile(source, filename, mode, flag)
-        except SyntaxError:
+        except SyntaxError as ex:
-            ex = sys.exc_info()[1]
             # re-represent syntax errors from parsing python strings
             msglines = self.lines[: ex.lineno]
             if ex.offset:
@@ -173,7 +173,8 @@ class Source:
             if flag & _AST_FLAG:
                 return co
             lines = [(x + "\n") for x in self.lines]
-            linecache.cache[filename] = (1, None, lines, filename)
+            # Type ignored because linecache.cache is private.
+            linecache.cache[filename] = (1, None, lines, filename)  # type: ignore
             return co
 
 
@@ -282,7 +283,7 @@ def get_statement_startend2(lineno, node):
     return start, end
 
 
-def getstatementrange_ast(lineno, source, assertion=False, astnode=None):
+def getstatementrange_ast(lineno, source: Source, assertion=False, astnode=None):
     if astnode is None:
         content = str(source)
         # See #4260:

src/_pytest/assertion/__init__.py

@@ -2,6 +2,7 @@
 support for presenting detailed information in failing assertions.
 """
 import sys
+from typing import Optional
 
 from _pytest.assertion import rewrite
 from _pytest.assertion import truncate
@@ -52,7 +53,9 @@ def register_assert_rewrite(*names):
             importhook = hook
             break
     else:
-        importhook = DummyRewriteHook()
+        # TODO(typing): Add a protocol for mark_rewrite() and use it
+        # for importhook and for PytestPluginManager.rewrite_hook.
+        importhook = DummyRewriteHook()  # type: ignore
     importhook.mark_rewrite(*names)
 
 
@@ -69,7 +72,7 @@ class AssertionState:
     def __init__(self, config, mode):
         self.mode = mode
         self.trace = config.trace.root.get("assertion")
-        self.hook = None
+        self.hook = None  # type: Optional[rewrite.AssertionRewritingHook]
 
 
 def install_importhook(config):
@@ -108,6 +111,7 @@ def pytest_runtest_setup(item):
     """
 
     def callbinrepr(op, left, right):
+        # type: (str, object, object) -> Optional[str]
         """Call the pytest_assertrepr_compare hook and prepare the result
 
         This uses the first result from the hook and then ensures the
@@ -133,12 +137,13 @@ def pytest_runtest_setup(item):
                 if item.config.getvalue("assertmode") == "rewrite":
                     res = res.replace("%", "%%")
                 return res
+        return None
 
     util._reprcompare = callbinrepr
 
     if item.ihook.pytest_assertion_pass.get_hookimpls():
 
-        def call_assertion_pass_hook(lineno, expl, orig):
+        def call_assertion_pass_hook(lineno, orig, expl):
             item.ihook.pytest_assertion_pass(
                 item=item, lineno=lineno, orig=orig, expl=expl
             )

src/_pytest/assertion/rewrite.py

@@ -2,6 +2,7 @@
 import ast
 import errno
 import functools
+import importlib.abc
 import importlib.machinery
 import importlib.util
 import io
@@ -16,6 +17,7 @@ from typing import Dict
 from typing import List
 from typing import Optional
 from typing import Set
+from typing import Tuple
 
 import atomicwrites
 
@@ -34,7 +36,7 @@ PYC_EXT = ".py" + (__debug__ and "c" or "o")
 PYC_TAIL = "." + PYTEST_TAG + PYC_EXT
 
 
-class AssertionRewritingHook:
+class AssertionRewritingHook(importlib.abc.MetaPathFinder):
     """PEP302/PEP451 import hook which rewrites asserts."""
 
     def __init__(self, config):
@@ -44,13 +46,13 @@ class AssertionRewritingHook:
         except ValueError:
             self.fnpats = ["test_*.py", "*_test.py"]
         self.session = None
-        self._rewritten_names = set()
+        self._rewritten_names = set()  # type: Set[str]
-        self._must_rewrite = set()
+        self._must_rewrite = set()  # type: Set[str]
         # flag to guard against trying to rewrite a pyc file while we are already writing another pyc file,
         # which might result in infinite recursion (#3506)
         self._writing_pyc = False
         self._basenames_to_check_rewrite = {"conftest"}
-        self._marked_for_rewrite_cache = {}
+        self._marked_for_rewrite_cache = {}  # type: Dict[str, bool]
         self._session_paths_checked = False
 
     def set_session(self, session):
@@ -199,7 +201,7 @@ class AssertionRewritingHook:
 
         return self._is_marked_for_rewrite(name, state)
 
-    def _is_marked_for_rewrite(self, name, state):
+    def _is_marked_for_rewrite(self, name: str, state):
         try:
             return self._marked_for_rewrite_cache[name]
         except KeyError:
@@ -214,7 +216,7 @@ class AssertionRewritingHook:
             self._marked_for_rewrite_cache[name] = False
             return False
 
-    def mark_rewrite(self, *names):
+    def mark_rewrite(self, *names: str) -> None:
         """Mark import names as needing to be rewritten.
 
         The named module or package as well as any nested modules will
@@ -381,6 +383,7 @@ def _format_boolop(explanations, is_or):
 
 
 def _call_reprcompare(ops, results, expls, each_obj):
+    # type: (Tuple[str, ...], Tuple[bool, ...], Tuple[str, ...], Tuple[object, ...]) -> str
     for i, res, expl in zip(range(len(ops)), results, expls):
         try:
             done = not res
@@ -396,11 +399,13 @@ def _call_reprcompare(ops, results, expls, each_obj):
 
 
 def _call_assertion_pass(lineno, orig, expl):
+    # type: (int, str, str) -> None
     if util._assertion_pass is not None:
-        util._assertion_pass(lineno=lineno, orig=orig, expl=expl)
+        util._assertion_pass(lineno, orig, expl)
 
 
 def _check_if_assertion_pass_impl():
+    # type: () -> bool
     """Checks if any plugins implement the pytest_assertion_pass hook
     in order not to generate explanation unecessarily (might be expensive)"""
     return True if util._assertion_pass else False
@@ -574,7 +579,7 @@ class AssertionRewriter(ast.NodeVisitor):
     def _assert_expr_to_lineno(self):
         return _get_assertion_exprs(self.source)
 
-    def run(self, mod):
+    def run(self, mod: ast.Module) -> None:
         """Find all assert statements in *mod* and rewrite them."""
         if not mod.body:
             # Nothing to do.
@@ -616,12 +621,12 @@ class AssertionRewriter(ast.NodeVisitor):
         ]
         mod.body[pos:pos] = imports
         # Collect asserts.
-        nodes = [mod]
+        nodes = [mod]  # type: List[ast.AST]
         while nodes:
             node = nodes.pop()
             for name, field in ast.iter_fields(node):
                 if isinstance(field, list):
-                    new = []
+                    new = []  # type: List
                     for i, child in enumerate(field):
                         if isinstance(child, ast.Assert):
                             # Transform assert.
@@ -695,7 +700,7 @@ class AssertionRewriter(ast.NodeVisitor):
         .explanation_param().
 
         """
-        self.explanation_specifiers = {}
+        self.explanation_specifiers = {}  # type: Dict[str, ast.expr]
         self.stack.append(self.explanation_specifiers)
 
     def pop_format_context(self, expl_expr):
@@ -738,7 +743,8 @@ class AssertionRewriter(ast.NodeVisitor):
             from _pytest.warning_types import PytestAssertRewriteWarning
             import warnings
 
-            warnings.warn_explicit(
+            # Ignore type: typeshed bug https://github.com/python/typeshed/pull/3121
+            warnings.warn_explicit(  # type: ignore
                 PytestAssertRewriteWarning(
                     "assertion is always true, perhaps remove parentheses?"
                 ),
@@ -747,15 +753,15 @@ class AssertionRewriter(ast.NodeVisitor):
                 lineno=assert_.lineno,
             )
 
-        self.statements = []
+        self.statements = []  # type: List[ast.stmt]
-        self.variables = []
+        self.variables = []  # type: List[str]
         self.variable_counter = itertools.count()
 
         if self.enable_assertion_pass_hook:
-            self.format_variables = []
+            self.format_variables = []  # type: List[str]
 
-        self.stack = []
+        self.stack = []  # type: List[Dict[str, ast.expr]]
-        self.expl_stmts = []
+        self.expl_stmts = []  # type: List[ast.stmt]
         self.push_format_context()
         # Rewrite assert into a bunch of statements.
         top_condition, explanation = self.visit(assert_.test)
@@ -893,7 +899,7 @@ warn_explicit(
         # Process each operand, short-circuiting if needed.
         for i, v in enumerate(boolop.values):
             if i:
-                fail_inner = []
+                fail_inner = []  # type: List[ast.stmt]
                 # cond is set in a prior loop iteration below
                 self.expl_stmts.append(ast.If(cond, fail_inner, []))  # noqa
                 self.expl_stmts = fail_inner
@@ -904,10 +910,10 @@ warn_explicit(
             call = ast.Call(app, [expl_format], [])
             self.expl_stmts.append(ast.Expr(call))
             if i < levels:
-                cond = res
+                cond = res  # type: ast.expr
                 if is_or:
                     cond = ast.UnaryOp(ast.Not(), cond)
-                inner = []
+                inner = []  # type: List[ast.stmt]
                 self.statements.append(ast.If(cond, inner, []))
                 self.statements = body = inner
         self.statements = save
@@ -973,7 +979,7 @@ warn_explicit(
         expl = pat % (res_expl, res_expl, value_expl, attr.attr)
         return res, expl
 
-    def visit_Compare(self, comp):
+    def visit_Compare(self, comp: ast.Compare):
         self.push_format_context()
         left_res, left_expl = self.visit(comp.left)
         if isinstance(comp.left, (ast.Compare, ast.BoolOp)):
@@ -1006,7 +1012,7 @@ warn_explicit(
             ast.Tuple(results, ast.Load()),
         )
         if len(comp.ops) > 1:
-            res = ast.BoolOp(ast.And(), load_names)
+            res = ast.BoolOp(ast.And(), load_names)  # type: ast.expr
         else:
             res = load_names[0]
         return res, self.explanation_param(self.pop_format_context(expl_call))

src/_pytest/assertion/util.py

@@ -1,6 +1,9 @@
 """Utilities for assertion debugging"""
 import pprint
 from collections.abc import Sequence
+from typing import Callable
+from typing import List
+from typing import Optional
 
 import _pytest._code
 from _pytest import outcomes
@@ -10,11 +13,11 @@ from _pytest._io.saferepr import saferepr
 # interpretation code and assertion rewriter to detect this plugin was
 # loaded and in turn call the hooks defined here as part of the
 # DebugInterpreter.
-_reprcompare = None
+_reprcompare = None  # type: Optional[Callable[[str, object, object], Optional[str]]]
 
 # Works similarly as _reprcompare attribute. Is populated with the hook call
 # when pytest_runtest_setup is called.
-_assertion_pass = None
+_assertion_pass = None  # type: Optional[Callable[[int, str, str], None]]
 
 
 def format_explanation(explanation):
@@ -177,7 +180,7 @@ def _diff_text(left, right, verbose=0):
     """
     from difflib import ndiff
 
-    explanation = []
+    explanation = []  # type: List[str]
 
     def escape_for_readable_diff(binary_text):
         """
@@ -235,7 +238,7 @@ def _compare_eq_verbose(left, right):
     left_lines = repr(left).splitlines(keepends)
     right_lines = repr(right).splitlines(keepends)
 
-    explanation = []
+    explanation = []  # type: List[str]
     explanation += ["-" + line for line in left_lines]
     explanation += ["+" + line for line in right_lines]
 
@@ -259,7 +262,7 @@ def _compare_eq_iterable(left, right, verbose=0):
 
 def _compare_eq_sequence(left, right, verbose=0):
     comparing_bytes = isinstance(left, bytes) and isinstance(right, bytes)
-    explanation = []
+    explanation = []  # type: List[str]
     len_left = len(left)
     len_right = len(right)
     for i in range(min(len_left, len_right)):
@@ -327,7 +330,7 @@ def _compare_eq_set(left, right, verbose=0):
 
 
 def _compare_eq_dict(left, right, verbose=0):
-    explanation = []
+    explanation = []  # type: List[str]
     set_left = set(left)
     set_right = set(right)
     common = set_left.intersection(set_right)

src/_pytest/config/__init__.py

@@ -9,6 +9,15 @@ import types
 import warnings
 from functools import lru_cache
 from pathlib import Path
+from types import TracebackType
+from typing import Any
+from typing import Callable
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Sequence
+from typing import Set
+from typing import Tuple
 
 import attr
 import py
@@ -32,6 +41,10 @@ from _pytest.outcomes import fail
 from _pytest.outcomes import Skipped
 from _pytest.warning_types import PytestConfigWarning
 
+if False:  # TYPE_CHECKING
+    from typing import Type
+
+
 hookimpl = HookimplMarker("pytest")
 hookspec = HookspecMarker("pytest")
 
@@ -40,7 +53,7 @@ class ConftestImportFailure(Exception):
     def __init__(self, path, excinfo):
         Exception.__init__(self, path, excinfo)
         self.path = path
-        self.excinfo = excinfo
+        self.excinfo = excinfo  # type: Tuple[Type[Exception], Exception, TracebackType]
 
 
 def main(args=None, plugins=None):
@@ -237,14 +250,18 @@ class PytestPluginManager(PluginManager):
 
     def __init__(self):
         super().__init__("pytest")
-        self._conftest_plugins = set()
+        # The objects are module objects, only used generically.
+        self._conftest_plugins = set()  # type: Set[object]
 
         # state related to local conftest plugins
-        self._dirpath2confmods = {}
+        # Maps a py.path.local to a list of module objects.
-        self._conftestpath2mod = {}
+        self._dirpath2confmods = {}  # type: Dict[Any, List[object]]
+        # Maps a py.path.local to a module object.
+        self._conftestpath2mod = {}  # type: Dict[Any, object]
         self._confcutdir = None
         self._noconftest = False
-        self._duplicatepaths = set()
+        # Set of py.path.local's.
+        self._duplicatepaths = set()  # type: Set[Any]
 
         self.add_hookspecs(_pytest.hookspec)
         self.register(self)
@@ -656,7 +673,7 @@ class Config:
 
         args = attr.ib()
         plugins = attr.ib()
-        dir = attr.ib()
+        dir = attr.ib(type=Path)
 
     def __init__(self, pluginmanager, *, invocation_params=None):
         from .argparsing import Parser, FILE_OR_DIR
@@ -677,10 +694,10 @@ class Config:
         self.pluginmanager = pluginmanager
         self.trace = self.pluginmanager.trace.root.get("config")
         self.hook = self.pluginmanager.hook
-        self._inicache = {}
+        self._inicache = {}  # type: Dict[str, Any]
-        self._override_ini = ()
+        self._override_ini = ()  # type: Sequence[str]
-        self._opt2dest = {}
+        self._opt2dest = {}  # type: Dict[str, str]
-        self._cleanup = []
+        self._cleanup = []  # type: List[Callable[[], None]]
         self.pluginmanager.register(self, "pytestconfig")
         self._configured = False
         self.hook.pytest_addoption.call_historic(kwargs=dict(parser=self._parser))
@@ -781,7 +798,7 @@ class Config:
     def pytest_load_initial_conftests(self, early_config):
         self.pluginmanager._set_initial_conftests(early_config.known_args_namespace)
 
-    def _initini(self, args):
+    def _initini(self, args) -> None:
         ns, unknown_args = self._parser.parse_known_and_unknown_args(
             args, namespace=copy.copy(self.option)
         )
@@ -882,8 +899,7 @@ class Config:
             self.hook.pytest_load_initial_conftests(
                 early_config=self, args=args, parser=self._parser
             )
-        except ConftestImportFailure:
+        except ConftestImportFailure as e:
-            e = sys.exc_info()[1]
             if ns.help or ns.version:
                 # we don't want to prevent --help/--version to work
                 # so just let is pass and print a warning at the end
@@ -949,7 +965,7 @@ class Config:
         assert isinstance(x, list)
         x.append(line)  # modifies the cached list inline
 
-    def getini(self, name):
+    def getini(self, name: str):
         """ return configuration value from an :ref:`ini file <inifiles>`. If the
         specified name hasn't been registered through a prior
         :py:func:`parser.addini <_pytest.config.Parser.addini>`
@@ -960,7 +976,7 @@ class Config:
             self._inicache[name] = val = self._getini(name)
             return val
 
-    def _getini(self, name):
+    def _getini(self, name: str) -> Any:
         try:
             description, type, default = self._parser._inidict[name]
         except KeyError:
@@ -1005,7 +1021,7 @@ class Config:
             values.append(relroot)
         return values
 
-    def _get_override_ini_value(self, name):
+    def _get_override_ini_value(self, name: str) -> Optional[str]:
         value = None
         # override_ini is a list of "ini=value" options
         # always use the last item if multiple values are set for same ini-name,
@@ -1020,7 +1036,7 @@ class Config:
                     value = user_ini_value
         return value
 
-    def getoption(self, name, default=notset, skip=False):
+    def getoption(self, name: str, default=notset, skip: bool = False):
         """ return command line option value.
 
         :arg name: name of the option.  You may also specify

src/_pytest/config/argparsing.py

@@ -2,6 +2,11 @@ import argparse
 import sys
 import warnings
 from gettext import gettext
+from typing import Any
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Tuple
 
 import py
 
@@ -21,12 +26,12 @@ class Parser:
 
     def __init__(self, usage=None, processopt=None):
         self._anonymous = OptionGroup("custom options", parser=self)
-        self._groups = []
+        self._groups = []  # type: List[OptionGroup]
         self._processopt = processopt
         self._usage = usage
-        self._inidict = {}
+        self._inidict = {}  # type: Dict[str, Tuple[str, Optional[str], Any]]
-        self._ininames = []
+        self._ininames = []  # type: List[str]
-        self.extra_info = {}
+        self.extra_info = {}  # type: Dict[str, Any]
 
     def processoption(self, option):
         if self._processopt:
@@ -80,7 +85,7 @@ class Parser:
         args = [str(x) if isinstance(x, py.path.local) else x for x in args]
         return self.optparser.parse_args(args, namespace=namespace)
 
-    def _getparser(self):
+    def _getparser(self) -> "MyOptionParser":
         from _pytest._argcomplete import filescompleter
 
         optparser = MyOptionParser(self, self.extra_info, prog=self.prog)
@@ -94,7 +99,10 @@ class Parser:
                     a = option.attrs()
                     arggroup.add_argument(*n, **a)
         # bash like autocompletion for dirs (appending '/')
-        optparser.add_argument(FILE_OR_DIR, nargs="*").completer = filescompleter
+        # Type ignored because typeshed doesn't know about argcomplete.
+        optparser.add_argument(  # type: ignore
+            FILE_OR_DIR, nargs="*"
+        ).completer = filescompleter
         return optparser
 
     def parse_setoption(self, args, option, namespace=None):
@@ -103,13 +111,15 @@ class Parser:
             setattr(option, name, value)
         return getattr(parsedoption, FILE_OR_DIR)
 
-    def parse_known_args(self, args, namespace=None):
+    def parse_known_args(self, args, namespace=None) -> argparse.Namespace:
         """parses and returns a namespace object with known arguments at this
         point.
         """
         return self.parse_known_and_unknown_args(args, namespace=namespace)[0]
 
-    def parse_known_and_unknown_args(self, args, namespace=None):
+    def parse_known_and_unknown_args(
+        self, args, namespace=None
+    ) -> Tuple[argparse.Namespace, List[str]]:
         """parses and returns a namespace object with known arguments, and
         the remaining arguments unknown at this point.
         """
@@ -163,8 +173,8 @@ class Argument:
     def __init__(self, *names, **attrs):
         """store parms in private vars for use in add_argument"""
         self._attrs = attrs
-        self._short_opts = []
+        self._short_opts = []  # type: List[str]
-        self._long_opts = []
+        self._long_opts = []  # type: List[str]
         self.dest = attrs.get("dest")
         if "%default" in (attrs.get("help") or ""):
             warnings.warn(
@@ -268,8 +278,8 @@ class Argument:
                     )
                 self._long_opts.append(opt)
 
-    def __repr__(self):
+    def __repr__(self) -> str:
-        args = []
+        args = []  # type: List[str]
         if self._short_opts:
             args += ["_short_opts: " + repr(self._short_opts)]
         if self._long_opts:
@@ -286,7 +296,7 @@ class OptionGroup:
     def __init__(self, name, description="", parser=None):
         self.name = name
         self.description = description
-        self.options = []
+        self.options = []  # type: List[Argument]
         self.parser = parser
 
     def addoption(self, *optnames, **attrs):
@@ -405,6 +415,12 @@ class DropShorterLongHelpFormatter(argparse.HelpFormatter):
     - cache result on action object as this is called at least 2 times
     """
 
+    def __init__(self, *args, **kwargs):
+        """Use more accurate terminal width via pylib."""
+        if "width" not in kwargs:
+            kwargs["width"] = py.io.get_terminal_width()
+        super().__init__(*args, **kwargs)
+
     def _format_action_invocation(self, action):
         orgstr = argparse.HelpFormatter._format_action_invocation(self, action)
         if orgstr and orgstr[0] != "-":  # only optional arguments
@@ -421,7 +437,7 @@ class DropShorterLongHelpFormatter(argparse.HelpFormatter):
         option_map = getattr(action, "map_long_option", {})
         if option_map is None:
             option_map = {}
-        short_long = {}
+        short_long = {}  # type: Dict[str, str]
         for option in options:
             if len(option) == 2 or option[2] == " ":
                 continue

src/_pytest/config/findpaths.py

@@ -1,10 +1,15 @@
 import os
+from typing import List
+from typing import Optional
 
 import py
 
 from .exceptions import UsageError
 from _pytest.outcomes import fail
 
+if False:
+    from . import Config  # noqa: F401
+
 
 def exists(path, ignore=EnvironmentError):
     try:
@@ -102,7 +107,12 @@ def get_dirs_from_args(args):
 CFG_PYTEST_SECTION = "[pytest] section in {filename} files is no longer supported, change to [tool:pytest] instead."
 
 
-def determine_setup(inifile, args, rootdir_cmd_arg=None, config=None):
+def determine_setup(
+    inifile: str,
+    args: List[str],
+    rootdir_cmd_arg: Optional[str] = None,
+    config: Optional["Config"] = None,
+):
     dirs = get_dirs_from_args(args)
     if inifile:
         iniconfig = py.iniconfig.IniConfig(inifile)

src/_pytest/deprecated.py

@@ -29,3 +29,8 @@ RESULT_LOG = PytestDeprecationWarning(
     "--result-log is deprecated and scheduled for removal in pytest 6.0.\n"
     "See https://docs.pytest.org/en/latest/deprecations.html#result-log-result-log for more information."
 )
+
+FIXTURE_POSITIONAL_ARGUMENTS = PytestDeprecationWarning(
+    "Passing arguments to pytest.fixture() as positional arguments is deprecated - pass them "
+    "as a keyword argument instead."
+)

src/_pytest/fixtures.py

@@ -2,6 +2,7 @@ import functools
 import inspect
 import itertools
 import sys
+import warnings
 from collections import defaultdict
 from collections import deque
 from collections import OrderedDict
@@ -27,6 +28,7 @@ from _pytest.compat import getlocation
 from _pytest.compat import is_generator
 from _pytest.compat import NOTSET
 from _pytest.compat import safe_getattr
+from _pytest.deprecated import FIXTURE_POSITIONAL_ARGUMENTS
 from _pytest.outcomes import fail
 from _pytest.outcomes import TEST_OUTCOME
 
@@ -58,7 +60,6 @@ def pytest_sessionstart(session):
 
 scopename2class = {}  # type: Dict[str, Type[nodes.Node]]
 
-
 scope2props = dict(session=())  # type: Dict[str, Tuple[str, ...]]
 scope2props["package"] = ("fspath",)
 scope2props["module"] = ("fspath", "module")
@@ -792,6 +793,25 @@ def _teardown_yield_fixture(fixturefunc, it):
         )
 
 
+def _eval_scope_callable(scope_callable, fixture_name, config):
+    try:
+        result = scope_callable(fixture_name=fixture_name, config=config)
+    except Exception:
+        raise TypeError(
+            "Error evaluating {} while defining fixture '{}'.\n"
+            "Expected a function with the signature (*, fixture_name, config)".format(
+                scope_callable, fixture_name
+            )
+        )
+    if not isinstance(result, str):
+        fail(
+            "Expected {} to return a 'str' while defining fixture '{}', but it returned:\n"
+            "{!r}".format(scope_callable, fixture_name, result),
+            pytrace=False,
+        )
+    return result
+
+
 class FixtureDef:
     """ A container for a factory definition. """
 
@@ -811,6 +831,8 @@ class FixtureDef:
         self.has_location = baseid is not None
         self.func = func
         self.argname = argname
+        if callable(scope):
+            scope = _eval_scope_callable(scope, argname, fixturemanager.config)
         self.scope = scope
         self.scopenum = scope2index(
             scope or "function",
@@ -995,7 +1017,57 @@ class FixtureFunctionMarker:
         return function
 
 
-def fixture(scope="function", params=None, autouse=False, ids=None, name=None):
+FIXTURE_ARGS_ORDER = ("scope", "params", "autouse", "ids", "name")
+
+
+def _parse_fixture_args(callable_or_scope, *args, **kwargs):
+    arguments = {
+        "scope": "function",
+        "params": None,
+        "autouse": False,
+        "ids": None,
+        "name": None,
+    }
+    kwargs = {
+        key: value for key, value in kwargs.items() if arguments.get(key) != value
+    }
+
+    fixture_function = None
+    if isinstance(callable_or_scope, str):
+        args = list(args)
+        args.insert(0, callable_or_scope)
+    else:
+        fixture_function = callable_or_scope
+
+    positionals = set()
+    for positional, argument_name in zip(args, FIXTURE_ARGS_ORDER):
+        arguments[argument_name] = positional
+        positionals.add(argument_name)
+
+    duplicated_kwargs = {kwarg for kwarg in kwargs.keys() if kwarg in positionals}
+    if duplicated_kwargs:
+        raise TypeError(
+            "The fixture arguments are defined as positional and keyword: {}. "
+            "Use only keyword arguments.".format(", ".join(duplicated_kwargs))
+        )
+
+    if positionals:
+        warnings.warn(FIXTURE_POSITIONAL_ARGUMENTS, stacklevel=2)
+
+    arguments.update(kwargs)
+
+    return fixture_function, arguments
+
+
+def fixture(
+    callable_or_scope=None,
+    *args,
+    scope="function",
+    params=None,
+    autouse=False,
+    ids=None,
+    name=None
+):
     """Decorator to mark a fixture factory function.
 
     This decorator can be used, with or without parameters, to define a
@@ -1041,21 +1113,55 @@ def fixture(scope="function", params=None, autouse=False, ids=None, name=None):
                 ``fixture_<fixturename>`` and then use
                 ``@pytest.fixture(name='<fixturename>')``.
     """
-    if callable(scope) and params is None and autouse is False:
+    fixture_function, arguments = _parse_fixture_args(
+        callable_or_scope,
+        *args,
+        scope=scope,
+        params=params,
+        autouse=autouse,
+        ids=ids,
+        name=name
+    )
+    scope = arguments.get("scope")
+    params = arguments.get("params")
+    autouse = arguments.get("autouse")
+    ids = arguments.get("ids")
+    name = arguments.get("name")
+
+    if fixture_function and params is None and autouse is False:
         # direct decoration
-        return FixtureFunctionMarker("function", params, autouse, name=name)(scope)
+        return FixtureFunctionMarker(scope, params, autouse, name=name)(
+            fixture_function
+        )
+
     if params is not None and not isinstance(params, (list, tuple)):
         params = list(params)
     return FixtureFunctionMarker(scope, params, autouse, ids=ids, name=name)
 
 
-def yield_fixture(scope="function", params=None, autouse=False, ids=None, name=None):
+def yield_fixture(
+    callable_or_scope=None,
+    *args,
+    scope="function",
+    params=None,
+    autouse=False,
+    ids=None,
+    name=None
+):
     """ (return a) decorator to mark a yield-fixture factory function.
 
     .. deprecated:: 3.0
         Use :py:func:`pytest.fixture` directly instead.
     """
-    return fixture(scope=scope, params=params, autouse=autouse, ids=ids, name=name)
+    return fixture(
+        callable_or_scope,
+        *args,
+        scope=scope,
+        params=params,
+        autouse=autouse,
+        ids=ids,
+        name=name
+    )
 
 
 defaultfuncargprefixmarker = fixture()

src/_pytest/mark/evaluate.py

@@ -51,6 +51,8 @@ class MarkEvaluator:
         except TEST_OUTCOME:
             self.exc = sys.exc_info()
             if isinstance(self.exc[1], SyntaxError):
+                # TODO: Investigate why SyntaxError.offset is Optional, and if it can be None here.
+                assert self.exc[1].offset is not None
                 msg = [" " * (self.exc[1].offset + 4) + "^"]
                 msg.append("SyntaxError: invalid syntax")
             else:

src/_pytest/mark/structures.py

@@ -292,7 +292,7 @@ class MarkGenerator:
     _config = None
     _markers = set()  # type: Set[str]
 
-    def __getattr__(self, name):
+    def __getattr__(self, name: str) -> MarkDecorator:
         if name[0] == "_":
             raise AttributeError("Marker name must NOT start with underscore")
 

src/_pytest/nodes.py

@@ -1,14 +1,26 @@
 import os
 import warnings
 from functools import lru_cache
+from typing import Any
+from typing import Dict
+from typing import List
+from typing import Set
+from typing import Tuple
+from typing import Union
 
 import py
 
 import _pytest._code
 from _pytest.compat import getfslineno
+from _pytest.mark.structures import Mark
+from _pytest.mark.structures import MarkDecorator
 from _pytest.mark.structures import NodeKeywords
 from _pytest.outcomes import fail
 
+if False:  # TYPE_CHECKING
+    # Imported here due to circular import.
+    from _pytest.fixtures import FixtureDef
+
 SEP = "/"
 
 tracebackcutdir = py.path.local(_pytest.__file__).dirpath()
@@ -78,13 +90,13 @@ class Node:
         self.keywords = NodeKeywords(self)
 
         #: the marker objects belonging to this node
-        self.own_markers = []
+        self.own_markers = []  # type: List[Mark]
 
         #: allow adding of extra keywords to use for matching
-        self.extra_keyword_matches = set()
+        self.extra_keyword_matches = set()  # type: Set[str]
 
         # used for storing artificial fixturedefs for direct parametrization
-        self._name2pseudofixturedef = {}
+        self._name2pseudofixturedef = {}  # type: Dict[str, FixtureDef]
 
         if nodeid is not None:
             assert "::()" not in nodeid
@@ -127,7 +139,8 @@ class Node:
                 )
             )
         path, lineno = get_fslocation_from_item(self)
-        warnings.warn_explicit(
+        # Type ignored: https://github.com/python/typeshed/pull/3121
+        warnings.warn_explicit(  # type: ignore
             warning,
             category=None,
             filename=str(path),
@@ -160,7 +173,9 @@ class Node:
         chain.reverse()
         return chain
 
-    def add_marker(self, marker, append=True):
+    def add_marker(
+        self, marker: Union[str, MarkDecorator], append: bool = True
+    ) -> None:
         """dynamically add a marker object to the node.
 
         :type marker: ``str`` or ``pytest.mark.*``  object
@@ -168,17 +183,19 @@ class Node:
             ``append=True`` whether to append the marker,
             if ``False`` insert at position ``0``.
         """
-        from _pytest.mark import MarkDecorator, MARK_GEN
+        from _pytest.mark import MARK_GEN
 
-        if isinstance(marker, str):
+        if isinstance(marker, MarkDecorator):
-            marker = getattr(MARK_GEN, marker)
+            marker_ = marker
-        elif not isinstance(marker, MarkDecorator):
+        elif isinstance(marker, str):
-            raise ValueError("is not a string or pytest.mark.* Marker")
+            marker_ = getattr(MARK_GEN, marker)
-        self.keywords[marker.name] = marker
-        if append:
-            self.own_markers.append(marker.mark)
         else:
-            self.own_markers.insert(0, marker.mark)
+            raise ValueError("is not a string or pytest.mark.* Marker")
+        self.keywords[marker_.name] = marker
+        if append:
+            self.own_markers.append(marker_.mark)
+        else:
+            self.own_markers.insert(0, marker_.mark)
 
     def iter_markers(self, name=None):
         """
@@ -211,7 +228,7 @@ class Node:
 
     def listextrakeywords(self):
         """ Return a set of all extra keywords in self and any parents."""
-        extra_keywords = set()
+        extra_keywords = set()  # type: Set[str]
         for item in self.listchain():
             extra_keywords.update(item.extra_keyword_matches)
         return extra_keywords
@@ -239,7 +256,8 @@ class Node:
         pass
 
     def _repr_failure_py(self, excinfo, style=None):
-        if excinfo.errisinstance(fail.Exception):
+        # Type ignored: see comment where fail.Exception is defined.
+        if excinfo.errisinstance(fail.Exception):  # type: ignore
             if not excinfo.value.pytrace:
                 return str(excinfo.value)
         fm = self.session._fixturemanager
@@ -383,13 +401,13 @@ class Item(Node):
 
     def __init__(self, name, parent=None, config=None, session=None, nodeid=None):
         super().__init__(name, parent, config, session, nodeid=nodeid)
-        self._report_sections = []
+        self._report_sections = []  # type: List[Tuple[str, str, str]]
 
         #: user properties is a list of tuples (name, value) that holds user
         #: defined properties for this test.
-        self.user_properties = []
+        self.user_properties = []  # type: List[Tuple[str, Any]]
 
-    def add_report_section(self, when, key, content):
+    def add_report_section(self, when: str, key: str, content: str) -> None:
         """
         Adds a new report section, similar to what's done internally to add stdout and
         stderr captured output::

src/_pytest/pastebin.py

@@ -59,20 +59,25 @@ def create_new_paste(contents):
     Creates a new paste using bpaste.net service.
 
     :contents: paste contents as utf-8 encoded bytes
-    :returns: url to the pasted contents
+    :returns: url to the pasted contents or error message
     """
     import re
     from urllib.request import urlopen
     from urllib.parse import urlencode
 
-    params = {"code": contents, "lexer": "python3", "expiry": "1week"}
+    params = {"code": contents, "lexer": "text", "expiry": "1week"}
     url = "https://bpaste.net"
-    response = urlopen(url, data=urlencode(params).encode("ascii")).read()
+    try:
-    m = re.search(r'href="/raw/(\w+)"', response.decode("utf-8"))
+        response = (
+            urlopen(url, data=urlencode(params).encode("ascii")).read().decode("utf-8")
+        )
+    except OSError as exc_info:  # urllib errors
+        return "bad response: %s" % exc_info
+    m = re.search(r'href="/raw/(\w+)"', response)
     if m:
         return "{}/show/{}".format(url, m.group(1))
     else:
-        return "bad response: " + response.decode("utf-8")
+        return "bad response: invalid format ('" + response + "')"
 
 
 def pytest_terminal_summary(terminalreporter):

src/_pytest/reports.py

@@ -1,5 +1,6 @@
 from pprint import pprint
 from typing import Optional
+from typing import Union
 
 import py
 
@@ -267,7 +268,8 @@ class TestReport(BaseReport):
             if not isinstance(excinfo, ExceptionInfo):
                 outcome = "failed"
                 longrepr = excinfo
-            elif excinfo.errisinstance(skip.Exception):
+            # Type ignored -- see comment where skip.Exception is defined.
+            elif excinfo.errisinstance(skip.Exception):  # type: ignore
                 outcome = "skipped"
                 r = excinfo._getreprcrash()
                 longrepr = (str(r.path), r.lineno, r.message)
@@ -431,7 +433,7 @@ def _report_kwargs_from_json(reportdict):
                 reprlocals=reprlocals,
                 filelocrepr=reprfileloc,
                 style=data["style"],
-            )
+            )  # type: Union[ReprEntry, ReprEntryNative]
         elif entry_type == "ReprEntryNative":
             reprentry = ReprEntryNative(data["lines"])
         else:

src/_pytest/runner.py

@@ -3,6 +3,10 @@ import bdb
 import os
 import sys
 from time import time
+from typing import Callable
+from typing import Dict
+from typing import List
+from typing import Tuple
 
 import attr
 
@@ -10,10 +14,14 @@ from .reports import CollectErrorRepr
 from .reports import CollectReport
 from .reports import TestReport
 from _pytest._code.code import ExceptionInfo
+from _pytest.nodes import Node
 from _pytest.outcomes import Exit
 from _pytest.outcomes import Skipped
 from _pytest.outcomes import TEST_OUTCOME
 
+if False:  # TYPE_CHECKING
+    from typing import Type
+
 #
 # pytest plugin hooks
 
@@ -118,6 +126,7 @@ def pytest_runtest_call(item):
     except Exception:
         # Store trace info to allow postmortem debugging
         type, value, tb = sys.exc_info()
+        assert tb is not None
         tb = tb.tb_next  # Skip *this* frame
         sys.last_type = type
         sys.last_value = value
@@ -185,7 +194,7 @@ def check_interactive_exception(call, report):
 def call_runtest_hook(item, when, **kwds):
     hookname = "pytest_runtest_" + when
     ihook = getattr(item.ihook, hookname)
-    reraise = (Exit,)
+    reraise = (Exit,)  # type: Tuple[Type[BaseException], ...]
     if not item.config.getoption("usepdb", False):
         reraise += (KeyboardInterrupt,)
     return CallInfo.from_call(
@@ -252,7 +261,8 @@ def pytest_make_collect_report(collector):
         skip_exceptions = [Skipped]
         unittest = sys.modules.get("unittest")
         if unittest is not None:
-            skip_exceptions.append(unittest.SkipTest)
+            # Type ignored because unittest is loaded dynamically.
+            skip_exceptions.append(unittest.SkipTest)  # type: ignore
         if call.excinfo.errisinstance(tuple(skip_exceptions)):
             outcome = "skipped"
             r = collector._repr_failure_py(call.excinfo, "line").reprcrash
@@ -266,7 +276,7 @@ def pytest_make_collect_report(collector):
     rep = CollectReport(
         collector.nodeid, outcome, longrepr, getattr(call, "result", None)
     )
-    rep.call = call  # see collect_one_node
+    rep.call = call  # type: ignore # see collect_one_node
     return rep
 
 
@@ -274,8 +284,8 @@ class SetupState:
     """ shared state for setting up/tearing down test items or collectors. """
 
     def __init__(self):
-        self.stack = []
+        self.stack = []  # type: List[Node]
-        self._finalizers = {}
+        self._finalizers = {}  # type: Dict[Node, List[Callable[[], None]]]
 
     def addfinalizer(self, finalizer, colitem):
         """ attach a finalizer to the given colitem. """
@@ -302,6 +312,7 @@ class SetupState:
                     exc = sys.exc_info()
         if exc:
             _, val, tb = exc
+            assert val is not None
             raise val.with_traceback(tb)
 
     def _teardown_with_finalization(self, colitem):
@@ -335,6 +346,7 @@ class SetupState:
                     exc = sys.exc_info()
         if exc:
             _, val, tb = exc
+            assert val is not None
             raise val.with_traceback(tb)
 
     def prepare(self, colitem):

testing/python/fixtures.py

@@ -2217,6 +2217,68 @@ class TestFixtureMarker:
             ["*ScopeMismatch*You tried*function*session*request*"]
         )
 
+    def test_dynamic_scope(self, testdir):
+        testdir.makeconftest(
+            """
+            import pytest
+
+
+            def pytest_addoption(parser):
+                parser.addoption("--extend-scope", action="store_true", default=False)
+
+
+            def dynamic_scope(fixture_name, config):
+                if config.getoption("--extend-scope"):
+                    return "session"
+                return "function"
+
+
+            @pytest.fixture(scope=dynamic_scope)
+            def dynamic_fixture(calls=[]):
+                calls.append("call")
+                return len(calls)
+
+        """
+        )
+
+        testdir.makepyfile(
+            """
+            def test_first(dynamic_fixture):
+                assert dynamic_fixture == 1
+
+
+            def test_second(dynamic_fixture):
+                assert dynamic_fixture == 2
+
+        """
+        )
+
+        reprec = testdir.inline_run()
+        reprec.assertoutcome(passed=2)
+
+        reprec = testdir.inline_run("--extend-scope")
+        reprec.assertoutcome(passed=1, failed=1)
+
+    def test_dynamic_scope_bad_return(self, testdir):
+        testdir.makepyfile(
+            """
+            import pytest
+
+            def dynamic_scope(**_):
+                return "wrong-scope"
+
+            @pytest.fixture(scope=dynamic_scope)
+            def fixture():
+                pass
+
+        """
+        )
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines(
+            "Fixture 'fixture' from test_dynamic_scope_bad_return.py "
+            "got an unexpected scope value 'wrong-scope'"
+        )
+
     def test_register_only_with_mark(self, testdir):
         testdir.makeconftest(
             """
@@ -4044,12 +4106,43 @@ def test_fixture_named_request(testdir):
     )
 
 
+def test_fixture_duplicated_arguments(testdir):
+    """Raise error if there are positional and keyword arguments for the same parameter (#1682)."""
+    with pytest.raises(TypeError) as excinfo:
+
+        @pytest.fixture("session", scope="session")
+        def arg(arg):
+            pass
+
+    assert (
+        str(excinfo.value)
+        == "The fixture arguments are defined as positional and keyword: scope. "
+        "Use only keyword arguments."
+    )
+
+
+def test_fixture_with_positionals(testdir):
+    """Raise warning, but the positionals should still works (#1682)."""
+    from _pytest.deprecated import FIXTURE_POSITIONAL_ARGUMENTS
+
+    with pytest.warns(pytest.PytestDeprecationWarning) as warnings:
+
+        @pytest.fixture("function", [0], True)
+        def fixture_with_positionals():
+            pass
+
+    assert str(warnings[0].message) == str(FIXTURE_POSITIONAL_ARGUMENTS)
+
+    assert fixture_with_positionals._pytestfixturefunction.scope == "function"
+    assert fixture_with_positionals._pytestfixturefunction.params == (0,)
+    assert fixture_with_positionals._pytestfixturefunction.autouse
+
+
 def test_indirect_fixture_does_not_break_scope(testdir):
     """Ensure that fixture scope is respected when using indirect fixtures (#570)"""
     testdir.makepyfile(
         """
         import pytest
-
         instantiated  = []
 
         @pytest.fixture(scope="session")

testing/test_config.py

@@ -1194,6 +1194,21 @@ def test_help_and_version_after_argument_error(testdir):
     assert result.ret == ExitCode.USAGE_ERROR
 
 
+def test_help_formatter_uses_py_get_terminal_width(testdir, monkeypatch):
+    from _pytest.config.argparsing import DropShorterLongHelpFormatter
+
+    monkeypatch.setenv("COLUMNS", "90")
+    formatter = DropShorterLongHelpFormatter("prog")
+    assert formatter._width == 90
+
+    monkeypatch.setattr("py.io.get_terminal_width", lambda: 160)
+    formatter = DropShorterLongHelpFormatter("prog")
+    assert formatter._width == 160
+
+    formatter = DropShorterLongHelpFormatter("prog", width=42)
+    assert formatter._width == 42
+
+
 def test_config_does_not_load_blocked_plugin_from_args(testdir):
     """This tests that pytest's config setup handles "-p no:X"."""
     p = testdir.makepyfile("def test(capfd): pass")

testing/test_pastebin.py

@@ -82,6 +82,47 @@ class TestPaste:
     def pastebin(self, request):
         return request.config.pluginmanager.getplugin("pastebin")
 
+    @pytest.fixture
+    def mocked_urlopen_fail(self, monkeypatch):
+        """
+        monkeypatch the actual urlopen call to emulate a HTTP Error 400
+        """
+        calls = []
+
+        import urllib.error
+        import urllib.request
+
+        def mocked(url, data):
+            calls.append((url, data))
+            raise urllib.error.HTTPError(url, 400, "Bad request", None, None)
+
+        monkeypatch.setattr(urllib.request, "urlopen", mocked)
+        return calls
+
+    @pytest.fixture
+    def mocked_urlopen_invalid(self, monkeypatch):
+        """
+        monkeypatch the actual urlopen calls done by the internal plugin
+        function that connects to bpaste service, but return a url in an
+        unexpected format
+        """
+        calls = []
+
+        def mocked(url, data):
+            calls.append((url, data))
+
+            class DummyFile:
+                def read(self):
+                    # part of html of a normal response
+                    return b'View <a href="/invalid/3c0c6750bd">raw</a>.'
+
+            return DummyFile()
+
+        import urllib.request
+
+        monkeypatch.setattr(urllib.request, "urlopen", mocked)
+        return calls
+
     @pytest.fixture
     def mocked_urlopen(self, monkeypatch):
         """
@@ -105,13 +146,26 @@ class TestPaste:
         monkeypatch.setattr(urllib.request, "urlopen", mocked)
         return calls
 
+    def test_pastebin_invalid_url(self, pastebin, mocked_urlopen_invalid):
+        result = pastebin.create_new_paste(b"full-paste-contents")
+        assert (
+            result
+            == "bad response: invalid format ('View <a href=\"/invalid/3c0c6750bd\">raw</a>.')"
+        )
+        assert len(mocked_urlopen_invalid) == 1
+
+    def test_pastebin_http_error(self, pastebin, mocked_urlopen_fail):
+        result = pastebin.create_new_paste(b"full-paste-contents")
+        assert result == "bad response: HTTP Error 400: Bad request"
+        assert len(mocked_urlopen_fail) == 1
+
     def test_create_new_paste(self, pastebin, mocked_urlopen):
         result = pastebin.create_new_paste(b"full-paste-contents")
         assert result == "https://bpaste.net/show/3c0c6750bd"
         assert len(mocked_urlopen) == 1
         url, data = mocked_urlopen[0]
         assert type(data) is bytes
-        lexer = "python3"
+        lexer = "text"
         assert url == "https://bpaste.net"
         assert "lexer=%s" % lexer in data.decode()
         assert "code=full-paste-contents" in data.decode()
@@ -127,4 +181,4 @@ class TestPaste:
 
         monkeypatch.setattr(urllib.request, "urlopen", response)
         result = pastebin.create_new_paste(b"full-paste-contents")
-        assert result == "bad response: something bad occurred"
+        assert result == "bad response: invalid format ('something bad occurred')"