minor: getbasetemp: dedent, improve assert

src/_pytest/tmpdir.py

@@ -60,29 +60,29 @@ class TempPathFactory(object):
 
     def getbasetemp(self):
         """ return base temporary directory. """
-        if self._basetemp is None:
+        if self._basetemp is not None:
-            if self._given_basetemp is not None:
-                basetemp = self._given_basetemp
-                ensure_reset_dir(basetemp)
-                basetemp = basetemp.resolve()
-            else:
-                from_env = os.environ.get("PYTEST_DEBUG_TEMPROOT")
-                temproot = Path(from_env or tempfile.gettempdir()).resolve()
-                user = get_user() or "unknown"
-                # use a sub-directory in the temproot to speed-up
-                # make_numbered_dir() call
-                rootdir = temproot.joinpath("pytest-of-{}".format(user))
-                rootdir.mkdir(exist_ok=True)
-                basetemp = make_numbered_dir_with_cleanup(
-                    prefix="pytest-", root=rootdir, keep=3, lock_timeout=LOCK_TIMEOUT
-                )
-            assert basetemp is not None
-            self._basetemp = t = basetemp
-            self._trace("new basetemp", t)
-            return t
-        else:
             return self._basetemp
 
+        if self._given_basetemp is not None:
+            basetemp = self._given_basetemp
+            ensure_reset_dir(basetemp)
+            basetemp = basetemp.resolve()
+        else:
+            from_env = os.environ.get("PYTEST_DEBUG_TEMPROOT")
+            temproot = Path(from_env or tempfile.gettempdir()).resolve()
+            user = get_user() or "unknown"
+            # use a sub-directory in the temproot to speed-up
+            # make_numbered_dir() call
+            rootdir = temproot.joinpath("pytest-of-{}".format(user))
+            rootdir.mkdir(exist_ok=True)
+            basetemp = make_numbered_dir_with_cleanup(
+                prefix="pytest-", root=rootdir, keep=3, lock_timeout=LOCK_TIMEOUT
+            )
+        assert basetemp is not None, basetemp
+        self._basetemp = t = basetemp
+        self._trace("new basetemp", t)
+        return t
+
 
 @attr.s
 class TempdirFactory(object):