Fix linting issues.

changelog/3610.feature.rst

@@ -1 +1 @@
-Added the `--trace` option to enter the debugger at the start of a test.
+Added the `--trace` option to enter the debugger at the start of a test.

doc/en/usage.rst

@@ -174,7 +174,7 @@ for example::
 .. _trace-option:
 
 Dropping to PDB_ (Python Debugger) at the start of a test
------------------------------------------------
+----------------------------------------------------------
 
 
 ``pytest`` allows one to drop into the PDB_ prompt immediately at the start of each test via a command line option::

src/_pytest/debugging.py

@@ -85,11 +85,11 @@ def pytest_pyfunc_call(pyfuncitem):
         if pyfuncitem._isyieldedfunction():
             pyfuncitem.args = [testfunction, pyfuncitem._args]
         else:
-            if 'func' in pyfuncitem._fixtureinfo.argnames:
+            if "func" in pyfuncitem._fixtureinfo.argnames:
                 raise ValueError("--trace can't be used with a fixture named func!")
-            pyfuncitem.funcargs['func'] = testfunction
+            pyfuncitem.funcargs["func"] = testfunction
             new_list = list(pyfuncitem._fixtureinfo.argnames)
-            new_list.append('func')
+            new_list.append("func")
             pyfuncitem._fixtureinfo.argnames = tuple(new_list)
     yield
 

testing/test_pdb.py

@@ -697,7 +697,7 @@ class TestDebuggingBreakpoints(object):
         assert "reading from stdin while output" not in rest
         TestPDB.flush(child)
 
-class TestTraceOption():
+class TestTraceOption:
     def test_trace_sets_breakpoint(self, testdir):
         p1 = testdir.makepyfile(
             """
@@ -712,4 +712,4 @@ class TestTraceOption():
         rest = child.read().decode("utf8")
         assert "1 passed" in rest
         assert "reading from stdin while output" not in rest
-        TestPDB.flush(child)
+        TestPDB.flush(child)