bpo-31003: IDLE - Add more tests for General tab (#2859)

* In configdialog: Document causal pathways in create_page_general.
Move related functions to follow this. Simplify some attribute names.
* In test_configdialog: Add tests for load and helplist functions.
Coverage for the general tab is now complete, and 63% overall.

1 files changed, 5 insertions, 1 deletions

diff --git a/Lib/idlelib/idle_test/mock_idle.py b/Lib/idlelib/idle_test/mock_idle.py
index 8f3147b..f279a52 100644
--- a/Lib/idlelib/idle_test/mock_idle.py
+++ b/Lib/idlelib/idle_test/mock_idle.py
@@ -13,14 +13,16 @@ class Func:
     self.args - capture positional arguments.
     self.kwds - capture keyword arguments.
     self.result - return or raise value set in __init__.
+    self.return_self - return self instead, to mock query class return.
 
     Most common use will probably be to mock instance methods.
     Given class instance, can set and delete as instance attribute.
     Mock_tk.Var and Mbox_func are special variants of this.
     '''
-    def __init__(self, result=None):
+    def __init__(self, result=None, return_self=False):
         self.called = 0
         self.result = result
+        self.return_self = return_self
         self.args = None
         self.kwds = None
     def __call__(self, *args, **kwds):
@@ -29,6 +31,8 @@ class Func:
         self.kwds = kwds
         if isinstance(self.result, BaseException):
             raise self.result
+        elif self.return_self:
+            return self
         else:
             return self.result