Move TWMock class to a fixture

Using a relative import like before was not very nice

2 files changed, 161 insertions, 203 deletions

diff --git a/testing/code/test_code.py b/testing/code/test_code.py
index d45795967..2f55720b4 100644
--- a/testing/code/test_code.py
+++ b/testing/code/test_code.py
@@ -1,8 +1,6 @@
 import sys
 from unittest import mock
 
-from test_excinfo import TWMock
-
 import _pytest._code
 import pytest
 
@@ -168,17 +166,15 @@ class TestTracebackEntry:
 
 
 class TestReprFuncArgs:
-    def test_not_raise_exception_with_mixed_encoding(self):
+    def test_not_raise_exception_with_mixed_encoding(self, tw_mock):
         from _pytest._code.code import ReprFuncArgs
 
-        tw = TWMock()
-
         args = [("unicode_string", "São Paulo"), ("utf8_string", b"S\xc3\xa3o Paulo")]
 
         r = ReprFuncArgs(args)
-        r.toterminal(tw)
+        r.toterminal(tw_mock)
 
         assert (
-            tw.lines[0]
+            tw_mock.lines[0]
             == r"unicode_string = São Paulo, utf8_string = b'S\xc3\xa3o Paulo'"
         )
diff --git a/testing/code/test_excinfo.py b/testing/code/test_excinfo.py
index 7742b4da9..bdd7a5a6f 100644
--- a/testing/code/test_excinfo.py
+++ b/testing/code/test_excinfo.py
@@ -31,33 +31,6 @@ def limited_recursion_depth():
     sys.setrecursionlimit(before)
 
 
-class TWMock:
-    WRITE = object()
-
-    def __init__(self):
-        self.lines = []
-        self.is_writing = False
-
-    def sep(self, sep, line=None):
-        self.lines.append((sep, line))
-
-    def write(self, msg, **kw):
-        self.lines.append((TWMock.WRITE, msg))
-
-    def line(self, line, **kw):
-        self.lines.append(line)
-
-    def markup(self, text, **kw):
-        return text
-
-    def get_write_msg(self, idx):
-        flag, msg = self.lines[idx]
-        assert flag == TWMock.WRITE
-        return msg
-
-    fullwidth = 80
-
-
 def test_excinfo_simple() -> None:
     try:
         raise ValueError
@@ -658,7 +631,7 @@ raise ValueError()
         assert loc.lineno == 3
         # assert loc.message == "ValueError: hello"
 
-    def test_repr_tracebackentry_lines2(self, importasmod):
+    def test_repr_tracebackentry_lines2(self, importasmod, tw_mock):
         mod = importasmod(
             """
             def func1(m, x, y, z):
@@ -678,13 +651,12 @@ raise ValueError()
         p = FormattedExcinfo(funcargs=True)
         repr_entry = p.repr_traceback_entry(entry)
         assert repr_entry.reprfuncargs.args == reprfuncargs.args
-        tw = TWMock()
-        repr_entry.toterminal(tw)
-        assert tw.lines[0] == "m = " + repr("m" * 90)
-        assert tw.lines[1] == "x = 5, y = 13"
-        assert tw.lines[2] == "z = " + repr("z" * 120)
+        repr_entry.toterminal(tw_mock)
+        assert tw_mock.lines[0] == "m = " + repr("m" * 90)
+        assert tw_mock.lines[1] == "x = 5, y = 13"
+        assert tw_mock.lines[2] == "z = " + repr("z" * 120)
 
-    def test_repr_tracebackentry_lines_var_kw_args(self, importasmod):
+    def test_repr_tracebackentry_lines_var_kw_args(self, importasmod, tw_mock):
         mod = importasmod(
             """
             def func1(x, *y, **z):
@@ -703,9 +675,8 @@ raise ValueError()
         p = FormattedExcinfo(funcargs=True)
         repr_entry = p.repr_traceback_entry(entry)
         assert repr_entry.reprfuncargs.args == reprfuncargs.args
-        tw = TWMock()
-        repr_entry.toterminal(tw)
-        assert tw.lines[0] == "x = 'a', y = ('b',), z = {'c': 'd'}"
+        repr_entry.toterminal(tw_mock)
+        assert tw_mock.lines[0] == "x = 'a', y = ('b',), z = {'c': 'd'}"
 
     def test_repr_tracebackentry_short(self, importasmod):
         mod = importasmod(
@@ -842,7 +813,7 @@ raise ValueError()
         assert p._makepath(__file__) == __file__
         p.repr_traceback(excinfo)
 
-    def test_repr_excinfo_addouterr(self, importasmod):
+    def test_repr_excinfo_addouterr(self, importasmod, tw_mock):
         mod = importasmod(
             """
             def entry():
@@ -852,10 +823,9 @@ raise ValueError()
         excinfo = pytest.raises(ValueError, mod.entry)
         repr = excinfo.getrepr()
         repr.addsection("title", "content")
-        twmock = TWMock()
-        repr.toterminal(twmock)
-        assert twmock.lines[-1] == "content"
-        assert twmock.lines[-2] == ("-", "title")
+        repr.toterminal(tw_mock)
+        assert tw_mock.lines[-1] == "content"
+        assert tw_mock.lines[-2] == ("-", "title")
 
     def test_repr_excinfo_reprcrash(self, importasmod):
         mod = importasmod(
@@ -920,7 +890,7 @@ raise ValueError()
         x = str(MyRepr())
         assert x == "я"
 
-    def test_toterminal_long(self, importasmod):
+    def test_toterminal_long(self, importasmod, tw_mock):
         mod = importasmod(
             """
             def g(x):
@@ -932,27 +902,26 @@ raise ValueError()
         excinfo = pytest.raises(ValueError, mod.f)
         excinfo.traceback = excinfo.traceback.filter()
         repr = excinfo.getrepr()
-        tw = TWMock()
-        repr.toterminal(tw)
-        assert tw.lines[0] == ""
-        tw.lines.pop(0)
-        assert tw.lines[0] == "    def f():"
-        assert tw.lines[1] == ">       g(3)"
-        assert tw.lines[2] == ""
-        line = tw.get_write_msg(3)
+        repr.toterminal(tw_mock)
+        assert tw_mock.lines[0] == ""
+        tw_mock.lines.pop(0)
+        assert tw_mock.lines[0] == "    def f():"
+        assert tw_mock.lines[1] == ">       g(3)"
+        assert tw_mock.lines[2] == ""
+        line = tw_mock.get_write_msg(3)
         assert line.endswith("mod.py")
-        assert tw.lines[4] == (":5: ")
-        assert tw.lines[5] == ("_ ", None)
-        assert tw.lines[6] == ""
-        assert tw.lines[7] == "    def g(x):"
-        assert tw.lines[8] == ">       raise ValueError(x)"
-        assert tw.lines[9] == "E       ValueError: 3"
-        assert tw.lines[10] == ""
-        line = tw.get_write_msg(11)
+        assert tw_mock.lines[4] == (":5: ")
+        assert tw_mock.lines[5] == ("_ ", None)
+        assert tw_mock.lines[6] == ""
+        assert tw_mock.lines[7] == "    def g(x):"
+        assert tw_mock.lines[8] == ">       raise ValueError(x)"
+        assert tw_mock.lines[9] == "E       ValueError: 3"
+        assert tw_mock.lines[10] == ""
+        line = tw_mock.get_write_msg(11)
         assert line.endswith("mod.py")
-        assert tw.lines[12] == ":3: ValueError"
+        assert tw_mock.lines[12] == ":3: ValueError"
 
-    def test_toterminal_long_missing_source(self, importasmod, tmpdir):
+    def test_toterminal_long_missing_source(self, importasmod, tmpdir, tw_mock):
         mod = importasmod(
             """
             def g(x):
@@ -965,25 +934,24 @@ raise ValueError()
         tmpdir.join("mod.py").remove()
         excinfo.traceback = excinfo.traceback.filter()
         repr = excinfo.getrepr()
-        tw = TWMock()
-        repr.toterminal(tw)
-        assert tw.lines[0] == ""
-        tw.lines.pop(0)
-        assert tw.lines[0] == ">   ???"
-        assert tw.lines[1] == ""
-        line = tw.get_write_msg(2)
+        repr.toterminal(tw_mock)
+        assert tw_mock.lines[0] == ""
+        tw_mock.lines.pop(0)
+        assert tw_mock.lines[0] == ">   ???"
+        assert tw_mock.lines[1] == ""
+        line = tw_mock.get_write_msg(2)
         assert line.endswith("mod.py")
-        assert tw.lines[3] == ":5: "
-        assert tw.lines[4] == ("_ ", None)
-        assert tw.lines[5] == ""
-        assert tw.lines[6] == ">   ???"
-        assert tw.lines[7] == "E   ValueError: 3"
-        assert tw.lines[8] == ""
-        line = tw.get_write_msg(9)
+        assert tw_mock.lines[3] == ":5: "
+        assert tw_mock.lines[4] == ("_ ", None)
+        assert tw_mock.lines[5] == ""
+        assert tw_mock.lines[6] == ">   ???"
+        assert tw_mock.lines[7] == "E   ValueError: 3"
+        assert tw_mock.lines[8] == ""
+        line = tw_mock.get_write_msg(9)
         assert line.endswith("mod.py")
-        assert tw.lines[10] == ":3: ValueError"
+        assert tw_mock.lines[10] == ":3: ValueError"
 
-    def test_toterminal_long_incomplete_source(self, importasmod, tmpdir):
+    def test_toterminal_long_incomplete_source(self, importasmod, tmpdir, tw_mock):
         mod = importasmod(
             """
             def g(x):
@@ -996,25 +964,24 @@ raise ValueError()
         tmpdir.join("mod.py").write("asdf")
         excinfo.traceback = excinfo.traceback.filter()
         repr = excinfo.getrepr()
-        tw = TWMock()
-        repr.toterminal(tw)
-        assert tw.lines[0] == ""
-        tw.lines.pop(0)
-        assert tw.lines[0] == ">   ???"
-        assert tw.lines[1] == ""
-        line = tw.get_write_msg(2)
+        repr.toterminal(tw_mock)
+        assert tw_mock.lines[0] == ""
+        tw_mock.lines.pop(0)
+        assert tw_mock.lines[0] == ">   ???"
+        assert tw_mock.lines[1] == ""
+        line = tw_mock.get_write_msg(2)
         assert line.endswith("mod.py")
-        assert tw.lines[3] == ":5: "
-        assert tw.lines[4] == ("_ ", None)
-        assert tw.lines[5] == ""
-        assert tw.lines[6] == ">   ???"
-        assert tw.lines[7] == "E   ValueError: 3"
-        assert tw.lines[8] == ""
-        line = tw.get_write_msg(9)
+        assert tw_mock.lines[3] == ":5: "
+        assert tw_mock.lines[4] == ("_ ", None)
+        assert tw_mock.lines[5] == ""
+        assert tw_mock.lines[6] == ">   ???"
+        assert tw_mock.lines[7] == "E   ValueError: 3"
+        assert tw_mock.lines[8] == ""
+        line = tw_mock.get_write_msg(9)
         assert line.endswith("mod.py")
-        assert tw.lines[10] == ":3: ValueError"
+        assert tw_mock.lines[10] == ":3: ValueError"
 
-    def test_toterminal_long_filenames(self, importasmod):
+    def test_toterminal_long_filenames(self, importasmod, tw_mock):
         mod = importasmod(
             """
             def f():
@@ -1022,23 +989,22 @@ raise ValueError()
         """
         )
         excinfo = pytest.raises(ValueError, mod.f)
-        tw = TWMock()
         path = py.path.local(mod.__file__)
         old = path.dirpath().chdir()
         try:
             repr = excinfo.getrepr(abspath=False)
-            repr.toterminal(tw)
+            repr.toterminal(tw_mock)
             x = py.path.local().bestrelpath(path)
             if len(x) < len(str(path)):
-                msg = tw.get_write_msg(-2)
+                msg = tw_mock.get_write_msg(-2)
                 assert msg == "mod.py"
-                assert tw.lines[-1] == ":3: ValueError"
+                assert tw_mock.lines[-1] == ":3: ValueError"
 
             repr = excinfo.getrepr(abspath=True)
-            repr.toterminal(tw)
-            msg = tw.get_write_msg(-2)
+            repr.toterminal(tw_mock)
+            msg = tw_mock.get_write_msg(-2)
             assert msg == path
-            line = tw.lines[-1]
+            line = tw_mock.lines[-1]
             assert line == ":3: ValueError"
         finally:
             old.chdir()
@@ -1073,7 +1039,7 @@ raise ValueError()
         repr.toterminal(tw)
         assert tw.stringio.getvalue()
 
-    def test_traceback_repr_style(self, importasmod):
+    def test_traceback_repr_style(self, importasmod, tw_mock):
         mod = importasmod(
             """
             def f():
@@ -1091,35 +1057,34 @@ raise ValueError()
         excinfo.traceback[1].set_repr_style("short")
         excinfo.traceback[2].set_repr_style("short")
         r = excinfo.getrepr(style="long")
-        tw = TWMock()
-        r.toterminal(tw)
-        for line in tw.lines:
+        r.toterminal(tw_mock)
+        for line in tw_mock.lines:
             print(line)
-        assert tw.lines[0] == ""
-        assert tw.lines[1] == "    def f():"
-        assert tw.lines[2] == ">       g()"
-        assert tw.lines[3] == ""
-        msg = tw.get_write_msg(4)
+        assert tw_mock.lines[0] == ""
+        assert tw_mock.lines[1] == "    def f():"
+        assert tw_mock.lines[2] == ">       g()"
+        assert tw_mock.lines[3] == ""
+        msg = tw_mock.get_write_msg(4)
         assert msg.endswith("mod.py")
-        assert tw.lines[5] == ":3: "
-        assert tw.lines[6] == ("_ ", None)
-        tw.get_write_msg(7)
-        assert tw.lines[8].endswith("in g")
-        assert tw.lines[9] == "    h()"
-        tw.get_write_msg(10)
-        assert tw.lines[11].endswith("in h")
-        assert tw.lines[12] == "    i()"
-        assert tw.lines[13] == ("_ ", None)
-        assert tw.lines[14] == ""
-        assert tw.lines[15] == "    def i():"
-        assert tw.lines[16] == ">       raise ValueError()"
-        assert tw.lines[17] == "E       ValueError"
-        assert tw.lines[18] == ""
-        msg = tw.get_write_msg(19)
+        assert tw_mock.lines[5] == ":3: "
+        assert tw_mock.lines[6] == ("_ ", None)
+        tw_mock.get_write_msg(7)
+        assert tw_mock.lines[8].endswith("in g")
+        assert tw_mock.lines[9] == "    h()"
+        tw_mock.get_write_msg(10)
+        assert tw_mock.lines[11].endswith("in h")
+        assert tw_mock.lines[12] == "    i()"
+        assert tw_mock.lines[13] == ("_ ", None)
+        assert tw_mock.lines[14] == ""
+        assert tw_mock.lines[15] == "    def i():"
+        assert tw_mock.lines[16] == ">       raise ValueError()"
+        assert tw_mock.lines[17] == "E       ValueError"
+        assert tw_mock.lines[18] == ""
+        msg = tw_mock.get_write_msg(19)
         msg.endswith("mod.py")
-        assert tw.lines[20] == ":9: ValueError"
+        assert tw_mock.lines[20] == ":9: ValueError"
 
-    def test_exc_chain_repr(self, importasmod):
+    def test_exc_chain_repr(self, importasmod, tw_mock):
         mod = importasmod(
             """
             class Err(Exception):
@@ -1140,72 +1105,71 @@ raise ValueError()
         )
         excinfo = pytest.raises(AttributeError, mod.f)
         r = excinfo.getrepr(style="long")
-        tw = TWMock()
-        r.toterminal(tw)
-        for line in tw.lines:
+        r.toterminal(tw_mock)
+        for line in tw_mock.lines:
             print(line)
-        assert tw.lines[0] == ""
-        assert tw.lines[1] == "    def f():"
-        assert tw.lines[2] == "        try:"
-        assert tw.lines[3] == ">           g()"
-        assert tw.lines[4] == ""
-        line = tw.get_write_msg(5)
+        assert tw_mock.lines[0] == ""
+        assert tw_mock.lines[1] == "    def f():"
+        assert tw_mock.lines[2] == "        try:"
+        assert tw_mock.lines[3] == ">           g()"
+        assert tw_mock.lines[4] == ""
+        line = tw_mock.get_write_msg(5)
         assert line.endswith("mod.py")
-        assert tw.lines[6] == ":6: "
-        assert tw.lines[7] == ("_ ", None)
-        assert tw.lines[8] == ""
-        assert tw.lines[9] == "    def g():"
-        assert tw.lines[10] == ">       raise ValueError()"
-        assert tw.lines[11] == "E       ValueError"
-        assert tw.lines[12] == ""
-        line = tw.get_write_msg(13)
+        assert tw_mock.lines[6] == ":6: "
+        assert tw_mock.lines[7] == ("_ ", None)
+        assert tw_mock.lines[8] == ""
+        assert tw_mock.lines[9] == "    def g():"
+        assert tw_mock.lines[10] == ">       raise ValueError()"
+        assert tw_mock.lines[11] == "E       ValueError"
+        assert tw_mock.lines[12] == ""
+        line = tw_mock.get_write_msg(13)
         assert line.endswith("mod.py")
-        assert tw.lines[14] == ":12: ValueError"
-        assert tw.lines[15] == ""
+        assert tw_mock.lines[14] == ":12: ValueError"
+        assert tw_mock.lines[15] == ""
         assert (
-            tw.lines[16]
+            tw_mock.lines[16]
             == "The above exception was the direct cause of the following exception:"
         )
-        assert tw.lines[17] == ""
-        assert tw.lines[18] == "    def f():"
-        assert tw.lines[19] == "        try:"
-        assert tw.lines[20] == "            g()"
-        assert tw.lines[21] == "        except Exception as e:"
-        assert tw.lines[22] == ">           raise Err() from e"
-        assert tw.lines[23] == "E           test_exc_chain_repr0.mod.Err"
-        assert tw.lines[24] == ""
-        line = tw.get_write_msg(25)
+        assert tw_mock.lines[17] == ""
+        assert tw_mock.lines[18] == "    def f():"
+        assert tw_mock.lines[19] == "        try:"
+        assert tw_mock.lines[20] == "            g()"
+        assert tw_mock.lines[21] == "        except Exception as e:"
+        assert tw_mock.lines[22] == ">           raise Err() from e"
+        assert tw_mock.lines[23] == "E           test_exc_chain_repr0.mod.Err"
+        assert tw_mock.lines[24] == ""
+        line = tw_mock.get_write_msg(25)
         assert line.endswith("mod.py")
-        assert tw.lines[26] == ":8: Err"
-        assert tw.lines[27] == ""
+        assert tw_mock.lines[26] == ":8: Err"
+        assert tw_mock.lines[27] == ""
         assert (
-            tw.lines[28]
+            tw_mock.lines[28]
             == "During handling of the above exception, another exception occurred:"
         )
-        assert tw.lines[29] == ""
-        assert tw.lines[30] == "    def f():"
-        assert tw.lines[31] == "        try:"
-        assert tw.lines[32] == "            g()"
-        assert tw.lines[33] == "        except Exception as e:"
-        assert tw.lines[34] == "            raise Err() from e"
-        assert tw.lines[35] == "        finally:"
-        assert tw.lines[36] == ">           h()"
-        assert tw.lines[37] == ""
-        line = tw.get_write_msg(38)
+        assert tw_mock.lines[29] == ""
+        assert tw_mock.lines[30] == "    def f():"
+        assert tw_mock.lines[31] == "        try:"
+        assert tw_mock.lines[32] == "            g()"
+        assert tw_mock.lines[33] == "        except Exception as e:"
+        assert tw_mock.lines[34] == "            raise Err() from e"
+        assert tw_mock.lines[35] == "        finally:"
+        assert tw_mock.lines[36] == ">           h()"
+        assert tw_mock.lines[37] == ""
+        line = tw_mock.get_write_msg(38)
         assert line.endswith("mod.py")
-        assert tw.lines[39] == ":10: "
-        assert tw.lines[40] == ("_ ", None)
-        assert tw.lines[41] == ""
-        assert tw.lines[42] == "    def h():"
-        assert tw.lines[43] == ">       raise AttributeError()"
-        assert tw.lines[44] == "E       AttributeError"
-        assert tw.lines[45] == ""
-        line = tw.get_write_msg(46)
+        assert tw_mock.lines[39] == ":10: "
+        assert tw_mock.lines[40] == ("_ ", None)
+        assert tw_mock.lines[41] == ""
+        assert tw_mock.lines[42] == "    def h():"
+        assert tw_mock.lines[43] == ">       raise AttributeError()"
+        assert tw_mock.lines[44] == "E       AttributeError"
+        assert tw_mock.lines[45] == ""
+        line = tw_mock.get_write_msg(46)
         assert line.endswith("mod.py")
-        assert tw.lines[47] == ":15: AttributeError"
+        assert tw_mock.lines[47] == ":15: AttributeError"
 
     @pytest.mark.parametrize("mode", ["from_none", "explicit_suppress"])
-    def test_exc_repr_chain_suppression(self, importasmod, mode):
+    def test_exc_repr_chain_suppression(self, importasmod, mode, tw_mock):
         """Check that exc repr does not show chained exceptions in Python 3.
         - When the exception is raised with "from None"
         - Explicitly suppressed with "chain=False" to ExceptionInfo.getrepr().
@@ -1226,24 +1190,23 @@ raise ValueError()
         )
         excinfo = pytest.raises(AttributeError, mod.f)
         r = excinfo.getrepr(style="long", chain=mode != "explicit_suppress")
-        tw = TWMock()
-        r.toterminal(tw)
-        for line in tw.lines:
+        r.toterminal(tw_mock)
+        for line in tw_mock.lines:
             print(line)
-        assert tw.lines[0] == ""
-        assert tw.lines[1] == "    def f():"
-        assert tw.lines[2] == "        try:"
-        assert tw.lines[3] == "            g()"
-        assert tw.lines[4] == "        except Exception:"
-        assert tw.lines[5] == ">           raise AttributeError(){}".format(
+        assert tw_mock.lines[0] == ""
+        assert tw_mock.lines[1] == "    def f():"
+        assert tw_mock.lines[2] == "        try:"
+        assert tw_mock.lines[3] == "            g()"
+        assert tw_mock.lines[4] == "        except Exception:"
+        assert tw_mock.lines[5] == ">           raise AttributeError(){}".format(
             raise_suffix
         )
-        assert tw.lines[6] == "E           AttributeError"
-        assert tw.lines[7] == ""
-        line = tw.get_write_msg(8)
+        assert tw_mock.lines[6] == "E           AttributeError"
+        assert tw_mock.lines[7] == ""
+        line = tw_mock.get_write_msg(8)
         assert line.endswith("mod.py")
-        assert tw.lines[9] == ":6: AttributeError"
-        assert len(tw.lines) == 10
+        assert tw_mock.lines[9] == ":6: AttributeError"
+        assert len(tw_mock.lines) == 10
 
     @pytest.mark.parametrize(
         "reason, description",
@@ -1304,7 +1267,7 @@ raise ValueError()
             ]
         )
 
-    def test_exc_chain_repr_cycle(self, importasmod):
+    def test_exc_chain_repr_cycle(self, importasmod, tw_mock):
         mod = importasmod(
             """
             class Err(Exception):
@@ -1325,9 +1288,8 @@ raise ValueError()
         )
         excinfo = pytest.raises(ZeroDivisionError, mod.unreraise)
         r = excinfo.getrepr(style="short")
-        tw = TWMock()
-        r.toterminal(tw)
-        out = "\n".join(line for line in tw.lines if isinstance(line, str))
+        r.toterminal(tw_mock)
+        out = "\n".join(line for line in tw_mock.lines if isinstance(line, str))
         expected_out = textwrap.dedent(
             """\
             :13: in unreraise