diff --git a/Lib/idlelib/SearchDialogBase.py b/Lib/idlelib/SearchDialogBase.py
index d258973..f0d7d51 100644
--- a/Lib/idlelib/SearchDialogBase.py
+++ b/Lib/idlelib/SearchDialogBase.py
@@ -16,10 +16,12 @@
     (make_button, create_command_buttons).
     These are bound to functions that execute the command.
 
-    Except for command buttons, this base class is not limited to
-    items common to all three subclasses.  Rather, it is the Find dialog
-    minus the "Find Next" command and its execution function.
-    The other dialogs override methods to replace and add widgets.
+    Except for command buttons, this base class is not limited to items
+    common to all three subclasses.  Rather, it is the Find dialog minus
+    the "Find Next" command, its execution function, and the
+    default_command attribute needed in create_widgets. The other
+    dialogs override attributes and methods, the latter to replace and
+    add widgets.
     '''
 
     title = "Search Dialog"  # replace in subclasses
@@ -30,9 +32,10 @@
         '''Initialize root, engine, and top attributes.
 
         top (level widget): set in create_widgets() called from open().
-        text (Text being searched): set in open(), only used in subclasses().
+        text (Text searched): set in open(), only used in subclasses().
         ent (ry): created in make_entry() called from create_entry().
         row (of grid): 0 in create_widgets(), +1 in make_entry/frame().
+        default_command: set in subclasses, used in create_widgers().
 
         title (of dialog): class attribute, override in subclasses.
         icon (of dialog): ditto, use unclear if cannot minimize dialog.
@@ -93,25 +96,27 @@
         e = Entry(self.top, textvariable=var, exportselection=0)
         e.grid(row=self.row, column=1, sticky="nwe")
         self.row = self.row + 1
-        return e
+        return l, e  # return label for testing
 
     def create_entries(self):
         "Create one or more entry lines with make_entry."
-        self.ent = self.make_entry("Find:", self.engine.patvar)
+        self.ent = self.make_entry("Find:", self.engine.patvar)[1]
 
     def make_frame(self,labeltext=None):
         "Return gridded labeled Frame for option or other buttons."
         if labeltext:
             l = Label(self.top, text=labeltext)
             l.grid(row=self.row, column=0, sticky="nw")
+        else:
+            l = ''
         f = Frame(self.top)
         f.grid(row=self.row, column=1, columnspan=1, sticky="nwe")
         self.row = self.row + 1
-        return f
+        return l, f
 
     def create_option_buttons(self):
         "Fill frame with Checkbuttons bound to SearchEngine booleanvars."
-        f = self.make_frame("Options")
+        f = self.make_frame("Options")[1]
 
         btn = Checkbutton(f, anchor="w",
                 variable=self.engine.revar,
@@ -144,7 +149,7 @@
 
     def create_other_buttons(self):
         "Fill frame with buttons tied to other options."
-        f = self.make_frame("Direction")
+        f = self.make_frame("Direction")[1]
 
         btn = Radiobutton(f, anchor="w",
                 variable=self.engine.backvar, value=1,
diff --git a/Lib/idlelib/idle_test/test_searchdialogbase.py b/Lib/idlelib/idle_test/test_searchdialogbase.py
new file mode 100644
index 0000000..df71ba3
--- /dev/null
+++ b/Lib/idlelib/idle_test/test_searchdialogbase.py
@@ -0,0 +1,198 @@
+'''Unittests for idlelib/SearchDialogBase.py
+
+Coverage: 99%. The only thing not covered is inconsequential --
+testing skipping of suite when self.needwrapbutton is false.
+
+'''
+import unittest
+from test.support import requires
+from tkinter import Tk, Toplevel, Frame, Label, BooleanVar, StringVar
+from idlelib import SearchEngine as se
+from idlelib import SearchDialogBase as sdb
+from idlelib.idle_test.mock_idle import Func
+from idlelib.idle_test.mock_tk import Var, Mbox
+
+# The following could help make some tests gui-free.
+# However, they currently make radiobutton tests fail.
+##def setUpModule():
+##    # Replace tk objects used to initialize se.SearchEngine.
+##    se.BooleanVar = Var
+##    se.StringVar = Var
+##
+##def tearDownModule():
+##    se.BooleanVar = BooleanVar
+##    se.StringVar = StringVar
+
+class SearchDialogBaseTest(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        requires('gui')
+        cls.root = Tk()
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.root.destroy()
+        del cls.root
+
+    def setUp(self):
+        self.engine = se.SearchEngine(self.root)  # None also seems to work
+        self.dialog = sdb.SearchDialogBase(root=self.root, engine=self.engine)
+
+    def tearDown(self):
+        self.dialog.close()
+
+    def test_open_and_close(self):
+        # open calls create_widgets, which needs default_command
+        self.dialog.default_command = None
+
+        # Since text parameter of .open is not used in base class,
+        # pass dummy 'text' instead of tk.Text().
+        self.dialog.open('text')
+        self.assertEqual(self.dialog.top.state(), 'normal')
+        self.dialog.close()
+        self.assertEqual(self.dialog.top.state(), 'withdrawn')
+
+        self.dialog.open('text', searchphrase="hello")
+        self.assertEqual(self.dialog.ent.get(), 'hello')
+        self.dialog.close()
+
+    def test_create_widgets(self):
+        self.dialog.create_entries = Func()
+        self.dialog.create_option_buttons = Func()
+        self.dialog.create_other_buttons = Func()
+        self.dialog.create_command_buttons = Func()
+
+        self.dialog.default_command = None
+        self.dialog.create_widgets()
+
+        self.assertTrue(self.dialog.create_entries.called)
+        self.assertTrue(self.dialog.create_option_buttons.called)
+        self.assertTrue(self.dialog.create_other_buttons.called)
+        self.assertTrue(self.dialog.create_command_buttons.called)
+
+    def test_make_entry(self):
+        equal = self.assertEqual
+        self.dialog.row = 0
+        self.dialog.top = Toplevel(self.root)
+        label, entry = self.dialog.make_entry("Test:", 'hello')
+        equal(label.cget('text'), 'Test:')
+
+        self.assertIn(entry.get(), 'hello')
+        egi = entry.grid_info()
+        equal(egi['row'], 0)
+        equal(egi['column'], 1)
+        equal(egi['rowspan'], 1)
+        equal(egi['columnspan'], 1)
+        equal(self.dialog.row, 1)
+
+    def test_create_entries(self):
+        self.dialog.row = 0
+        self.engine.setpat('hello')
+        self.dialog.create_entries()
+        self.assertIn(self.dialog.ent.get(), 'hello')
+
+    def test_make_frame(self):
+        self.dialog.row = 0
+        self.dialog.top = Toplevel(self.root)
+        label, frame = self.dialog.make_frame()
+        self.assertEqual(label, '')
+        self.assertIsInstance(frame, Frame)
+
+        label, labelledframe = self.dialog.make_frame('testlabel')
+        self.assertEqual(label.cget('text'), 'testlabel')
+        self.assertIsInstance(labelledframe, Frame)
+
+    def btn_test_setup(self, which):
+        self.dialog.row = 0
+        self.dialog.top = Toplevel(self.root)
+        if which == 'option':
+            self.dialog.create_option_buttons()
+        elif which == 'other':
+            self.dialog.create_other_buttons()
+        else:
+            raise ValueError('bad which arg %s' % which)
+
+    def test_create_option_buttons(self):
+        self.btn_test_setup('option')
+        self.checkboxtests()
+
+    def test_create_option_buttons_flipped(self):
+        for var in ('revar', 'casevar', 'wordvar', 'wrapvar'):
+            Var = getattr(self.engine, var)
+            Var.set(not Var.get())
+        self.btn_test_setup('option')
+        self.checkboxtests(flip=1)
+
+    def checkboxtests(self, flip=0):
+        """Tests the four checkboxes in the search dialog window."""
+        engine = self.engine
+        for child in self.dialog.top.winfo_children():
+            for grandchild in child.winfo_children():
+                text = grandchild.config()['text'][-1]
+                if text == ('Regular', 'expression'):
+                    self.btnstatetest(grandchild, engine.revar, flip)
+                elif text == ('Match', 'case'):
+                    self.btnstatetest(grandchild, engine.casevar, flip)
+                elif text == ('Whole', 'word'):
+                    self.btnstatetest(grandchild, engine.wordvar, flip)
+                elif text == ('Wrap', 'around'):
+                    self.btnstatetest(grandchild, engine.wrapvar, not flip)
+
+    def btnstatetest(self, button, var, defaultstate):
+        self.assertEqual(var.get(), defaultstate)
+        if defaultstate == 1:
+            button.deselect()
+        else:
+            button.select()
+        self.assertEqual(var.get(), 1 - defaultstate)
+
+    def test_create_other_buttons(self):
+        self.btn_test_setup('other')
+        self.radiobuttontests()
+
+    def test_create_other_buttons_flipped(self):
+        self.engine.backvar.set(1)
+        self.btn_test_setup('other')
+        self.radiobuttontests(back=1)
+
+    def radiobuttontests(self, back=0):
+        searchupbtn = None
+        searchdownbtn = None
+
+        for child in self.dialog.top.winfo_children():
+            for grandchild in child.children.values():
+                text = grandchild.config()['text'][-1]
+                if text == 'Up':
+                    searchupbtn = grandchild
+                elif text == 'Down':
+                    searchdownbtn = grandchild
+
+        # Defaults to searching downward
+        self.assertEqual(self.engine.backvar.get(), back)
+        if back:
+            searchdownbtn.select()
+        else:
+            searchupbtn.select()
+        self.assertEqual(self.engine.backvar.get(), not back)
+        searchdownbtn.select()
+
+    def test_make_button(self):
+        self.dialog.top = Toplevel(self.root)
+        self.dialog.buttonframe = Frame(self.dialog.top)
+        btn = self.dialog.make_button('Test', self.dialog.close)
+        self.assertEqual(btn.cget('text'), 'Test')
+
+    def test_create_command_buttons(self):
+        self.dialog.create_command_buttons()
+        # Look for close button command in buttonframe
+        closebuttoncommand = ''
+        for child in self.dialog.buttonframe.winfo_children():
+            if child.config()['text'][-1] == 'close':
+                closebuttoncommand = child.config()['command'][-1]
+        self.assertIn('close', closebuttoncommand)
+
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2, exit=2)