Issue #18489: Add complete, gui-free tests for idlelib.SearchEngine.

Patch import and initialization in SearchEngine to make testing easier.
Improve docstrings, especially to clarify the double role of 'ok' parameters.
Original patch by Phil Webster.

1 files changed, 326 insertions, 0 deletions

diff --git a/Lib/idlelib/idle_test/test_searchengine.py b/Lib/idlelib/idle_test/test_searchengine.py
new file mode 100644
index 0000000000..fdf38bd0ba
--- /dev/null
+++ b/Lib/idlelib/idle_test/test_searchengine.py
@@ -0,0 +1,326 @@
+'''Test functions and SearchEngine class in SearchEngine.py.'''
+
+# With mock replacements, the module does not use any gui widgets.
+# The use of tk.Text is avoided (for now, until mock Text is improved)
+# by patching instances with an index function returning what is needed.
+# This works because mock Text.get does not use .index.
+
+import re
+import unittest
+from test.support import requires
+from tkinter import  BooleanVar, StringVar, TclError  # ,Tk, Text
+import tkinter.messagebox as tkMessageBox
+from idlelib import SearchEngine as se
+from idlelib.idle_test.mock_tk import Var, Mbox
+from idlelib.idle_test.mock_tk import Text as mockText
+
+def setUpModule():
+    # Replace s-e module tkinter imports other than non-gui TclError.
+    se.BooleanVar = Var
+    se.StringVar = Var
+    se.tkMessageBox = Mbox
+
+def tearDownModule():
+    # Restore 'just in case', though other tests should also replace.
+    se.BooleanVar = BooleanVar
+    se.StringVar = StringVar
+    se.tkMessageBox = tkMessageBox
+
+
+class Mock:
+    def __init__(self, *args, **kwargs): pass
+
+class GetTest(unittest.TestCase):
+    # SearchEngine.get returns singleton created & saved on first call.
+    def test_get(self):
+        saved_Engine = se.SearchEngine
+        se.SearchEngine = Mock  # monkey-patch class
+        try:
+            root = Mock()
+            engine = se.get(root)
+            self.assertIsInstance(engine, se.SearchEngine)
+            self.assertIs(root._searchengine, engine)
+            self.assertIs(se.get(root), engine)
+        finally:
+            se.SearchEngine = saved_Engine  # restore class to module
+
+class GetLineColTest(unittest.TestCase):
+    #  Test simple text-independent helper function
+    def test_get_line_col(self):
+        self.assertEqual(se.get_line_col('1.0'), (1, 0))
+        self.assertEqual(se.get_line_col('1.11'), (1, 11))
+
+        self.assertRaises(ValueError, se.get_line_col, ('1.0 lineend'))
+        self.assertRaises(ValueError, se.get_line_col, ('end'))
+
+class GetSelectionTest(unittest.TestCase):
+    # Test text-dependent helper function.
+##    # Need gui for text.index('sel.first/sel.last/insert').
+##    @classmethod
+##    def setUpClass(cls):
+##        requires('gui')
+##        cls.root = Tk()
+##
+##    @classmethod
+##    def tearDownClass(cls):
+##        cls.root.destroy()
+
+    def test_get_selection(self):
+        # text = Text(master=self.root)
+        text = mockText()
+        text.insert('1.0',  'Hello World!')
+
+        # fix text.index result when called in get_selection
+        def sel(s):
+            # select entire text, cursor irrelevant
+            if s == 'sel.first': return '1.0'
+            if s == 'sel.last': return '1.12'
+            raise TclError
+        text.index = sel  # replaces .tag_add('sel', '1.0, '1.12')
+        self.assertEqual(se.get_selection(text), ('1.0', '1.12'))
+
+        def mark(s):
+            # no selection, cursor after 'Hello'
+            if s == 'insert': return '1.5'
+            raise TclError
+        text.index = mark  # replaces .mark_set('insert', '1.5')
+        self.assertEqual(se.get_selection(text), ('1.5', '1.5'))
+
+
+class ReverseSearchTest(unittest.TestCase):
+    # Test helper function that searches backwards within a line.
+    def test_search_reverse(self):
+        Equal = self.assertEqual
+        line = "Here is an 'is' test text."
+        prog = re.compile('is')
+        Equal(se.search_reverse(prog, line, len(line)).span(), (12, 14))
+        Equal(se.search_reverse(prog, line, 14).span(), (12, 14))
+        Equal(se.search_reverse(prog, line, 13).span(), (5, 7))
+        Equal(se.search_reverse(prog, line, 7).span(), (5, 7))
+        Equal(se.search_reverse(prog, line, 6), None)
+
+
+class SearchEngineTest(unittest.TestCase):
+    # Test class methods that do not use Text widget.
+
+    def setUp(self):
+        self.engine = se.SearchEngine(root=None)
+        # Engine.root is only used to create error message boxes.
+        # The mock replacement ignores the root argument.
+
+    def test_is_get(self):
+        engine = self.engine
+        Equal = self.assertEqual
+
+        Equal(engine.getpat(), '')
+        engine.setpat('hello')
+        Equal(engine.getpat(), 'hello')
+
+        Equal(engine.isre(), False)
+        engine.revar.set(1)
+        Equal(engine.isre(), True)
+
+        Equal(engine.iscase(), False)
+        engine.casevar.set(1)
+        Equal(engine.iscase(), True)
+
+        Equal(engine.isword(), False)
+        engine.wordvar.set(1)
+        Equal(engine.isword(), True)
+
+        Equal(engine.iswrap(), True)
+        engine.wrapvar.set(0)
+        Equal(engine.iswrap(), False)
+
+        Equal(engine.isback(), False)
+        engine.backvar.set(1)
+        Equal(engine.isback(), True)
+
+    def test_setcookedpat(self):
+        engine = self.engine
+        engine.setcookedpat('\s')
+        self.assertEqual(engine.getpat(), '\s')
+        engine.revar.set(1)
+        engine.setcookedpat('\s')
+        self.assertEqual(engine.getpat(), r'\\s')
+
+    def test_getcookedpat(self):
+        engine = self.engine
+        Equal = self.assertEqual
+
+        Equal(engine.getcookedpat(), '')
+        engine.setpat('hello')
+        Equal(engine.getcookedpat(), 'hello')
+        engine.wordvar.set(True)
+        Equal(engine.getcookedpat(), r'\bhello\b')
+        engine.wordvar.set(False)
+
+        engine.setpat('\s')
+        Equal(engine.getcookedpat(), r'\\s')
+        engine.revar.set(True)
+        Equal(engine.getcookedpat(), '\s')
+
+    def test_getprog(self):
+        engine = self.engine
+        Equal = self.assertEqual
+
+        engine.setpat('Hello')
+        temppat = engine.getprog()
+        Equal(temppat.pattern, re.compile('Hello', re.IGNORECASE).pattern)
+        engine.casevar.set(1)
+        temppat = engine.getprog()
+        Equal(temppat.pattern, re.compile('Hello').pattern, 0)
+
+        engine.setpat('')
+        Equal(engine.getprog(), None)
+        engine.setpat('+')
+        engine.revar.set(1)
+        Equal(engine.getprog(), None)
+        self.assertEqual(Mbox.showerror.message,
+                          'Error: nothing to repeat\nPattern: +')
+
+    def test_report_error(self):
+        showerror = Mbox.showerror
+        Equal = self.assertEqual
+        pat = '[a-z'
+        msg = 'unexpected end of regular expression'
+
+        Equal(self.engine.report_error(pat, msg), None)
+        Equal(showerror.title, 'Regular expression error')
+        expected_message = ("Error: " + msg + "\nPattern: [a-z")
+        Equal(showerror.message, expected_message)
+
+        Equal(self.engine.report_error(pat, msg, 5), None)
+        Equal(showerror.title, 'Regular expression error')
+        expected_message += "\nOffset: 5"
+        Equal(showerror.message, expected_message)
+
+
+class SearchTest(unittest.TestCase):
+    # Test that search_text makes right call to right method.
+
+    @classmethod
+    def setUpClass(cls):
+##        requires('gui')
+##        cls.root = Tk()
+##        cls.text = Text(master=cls.root)
+        cls.text = mockText()
+        test_text = (
+            'First line\n'
+            'Line with target\n'
+            'Last line\n')
+        cls.text.insert('1.0', test_text)
+        cls.pat = re.compile('target')
+
+        cls.engine = se.SearchEngine(None)
+        cls.engine.search_forward = lambda *args: ('f', args)
+        cls.engine.search_backward = lambda *args: ('b', args)
+
+##    @classmethod
+##    def tearDownClass(cls):
+##        cls.root.destroy()
+
+    def test_search(self):
+        Equal = self.assertEqual
+        engine = self.engine
+        search = engine.search_text
+        text = self.text
+        pat = self.pat
+
+        engine.patvar.set(None)
+        #engine.revar.set(pat)
+        Equal(search(text), None)
+
+        def mark(s):
+            # no selection, cursor after 'Hello'
+            if s == 'insert': return '1.5'
+            raise TclError
+        text.index = mark
+        Equal(search(text, pat), ('f', (text, pat, 1, 5, True, False)))
+        engine.wrapvar.set(False)
+        Equal(search(text, pat), ('f', (text, pat, 1, 5, False, False)))
+        engine.wrapvar.set(True)
+        engine.backvar.set(True)
+        Equal(search(text, pat), ('b', (text, pat, 1, 5, True, False)))
+        engine.backvar.set(False)
+
+        def sel(s):
+            if s == 'sel.first': return '2.10'
+            if s == 'sel.last': return '2.16'
+            raise TclError
+        text.index = sel
+        Equal(search(text, pat), ('f', (text, pat, 2, 16, True, False)))
+        Equal(search(text, pat, True), ('f', (text, pat, 2, 10, True, True)))
+        engine.backvar.set(True)
+        Equal(search(text, pat), ('b', (text, pat, 2, 10, True, False)))
+        Equal(search(text, pat, True), ('b', (text, pat, 2, 16, True, True)))
+
+
+class ForwardBackwardTest(unittest.TestCase):
+    # Test that search_forward method finds the target.
+##    @classmethod
+##    def tearDownClass(cls):
+##        cls.root.destroy()
+
+    @classmethod
+    def setUpClass(cls):
+        cls.engine = se.SearchEngine(None)
+##        requires('gui')
+##        cls.root = Tk()
+##        cls.text = Text(master=cls.root)
+        cls.text = mockText()
+        # search_backward calls index('end-1c')
+        cls.text.index = lambda index: '4.0'
+        test_text = (
+            'First line\n'
+            'Line with target\n'
+            'Last line\n')
+        cls.text.insert('1.0', test_text)
+        cls.pat = re.compile('target')
+        cls.res = (2, (10, 16))  # line, slice indexes of 'target'
+        cls.failpat = re.compile('xyz')  # not in text
+        cls.emptypat = re.compile('\w*')  # empty match possible
+
+    def make_search(self, func):
+        def search(pat, line, col, wrap, ok=0):
+            res = func(self.text, pat, line, col, wrap, ok)
+            # res is (line, matchobject) or None
+            return (res[0], res[1].span()) if res else res
+        return search
+
+    def test_search_forward(self):
+        # search for non-empty match
+        Equal = self.assertEqual
+        forward = self.make_search(self.engine.search_forward)
+        pat = self.pat
+        Equal(forward(pat, 1, 0, True), self.res)
+        Equal(forward(pat, 3, 0, True), self.res)  # wrap
+        Equal(forward(pat, 3, 0, False), None)  # no wrap
+        Equal(forward(pat, 2, 10, False), self.res)
+
+        Equal(forward(self.failpat, 1, 0, True), None)
+        Equal(forward(self.emptypat, 2,  9, True, ok=True), (2, (9, 9)))
+        #Equal(forward(self.emptypat, 2, 9, True), self.res)
+        # While the initial empty match is correctly ignored, skipping
+        # the rest of the line and returning (3, (0,4)) seems buggy - tjr.
+        Equal(forward(self.emptypat, 2, 10, True), self.res)
+
+    def test_search_backward(self):
+        # search for non-empty match
+        Equal = self.assertEqual
+        backward = self.make_search(self.engine.search_backward)
+        pat = self.pat
+        Equal(backward(pat, 3, 5, True), self.res)
+        Equal(backward(pat, 2, 0, True), self.res)  # wrap
+        Equal(backward(pat, 2, 0, False), None)  # no wrap
+        Equal(backward(pat, 2, 16, False), self.res)
+
+        Equal(backward(self.failpat, 3, 9, True), None)
+        Equal(backward(self.emptypat, 2,  10, True, ok=True), (2, (9,9)))
+        # Accepted because 9 < 10, not because ok=True.
+        # It is not clear that ok=True is useful going back - tjr
+        Equal(backward(self.emptypat, 2, 9, True), (2, (5, 9)))
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2, exit=2)