Add a Python 3 checker for finding deprecated calls to `str.translate`. (#1188)

* Add a Python 3 checker for finding deprecated calls to `str.translate`.

This checker could possibly have some false positives, but after checking our codebase
and several other large codebases using this implementation, I did not find any false
positives.

* Add filter for types proven not to be strings

1 files changed, 44 insertions, 0 deletions

diff --git a/pylint/test/unittest_checker_python3.py b/pylint/test/unittest_checker_python3.py
index 922bc4939..28a6d8052 100644
--- a/pylint/test/unittest_checker_python3.py
+++ b/pylint/test/unittest_checker_python3.py
@@ -647,6 +647,50 @@ class Python3CheckerTest(testutils.CheckerTestCase):
         with self.assertAddsMessages(absolute_import_message):
             self.checker.visit_importfrom(node)
 
+    @python2_only
+    def test_bad_str_translate_call_string_literal(self):
+        node = astroid.extract_node('''
+         foobar.translate(None, 'abc123') #@
+         ''')
+        message = testutils.Message('deprecated-str-translate-call', node=node)
+        with self.assertAddsMessages(message):
+            self.checker.visit_call(node)
+
+    @python2_only
+    def test_bad_str_translate_call_variable(self):
+        node = astroid.extract_node('''
+         foobar.translate(None, foobar) #@
+         ''')
+        message = testutils.Message('deprecated-str-translate-call', node=node)
+        with self.assertAddsMessages(message):
+            self.checker.visit_call(node)
+
+    @python2_only
+    def test_ok_str_translate_call_integer(self):
+        node = astroid.extract_node('''
+         foobar.translate(None, 33) #@
+         ''')
+        with self.assertNoMessages():
+            self.checker.visit_call(node)
+
+    @python2_only
+    def test_ok_str_translate_call_keyword(self):
+        node = astroid.extract_node('''
+         foobar.translate(None, 'foobar', raz=33) #@
+         ''')
+        with self.assertNoMessages():
+            self.checker.visit_call(node)
+
+    @python2_only
+    def test_ok_str_translate_call_not_str(self):
+        node = astroid.extract_node('''
+         foobar = {}
+         foobar.translate(None, 'foobar') #@
+         ''')
+        with self.assertNoMessages():
+            self.checker.visit_call(node)
+
+
 @python2_only
 class Python3TokenCheckerTest(testutils.CheckerTestCase):