Merge lp:~cjwatson/storm/case-sensitive-like-helpers into lp:storm

[Colin Watson]

Add optional case_sensitive argument to several Like helpers.

Comparable.startswith, Comparable.endswith, and Comparable.contains_string are convenience wrappers around Like, but none of them supported the case_sensitive option which Like supports on PostgreSQL. This made using PostgreSQL's ILIKE extension somewhat cumbersome in places: see https://code.launchpad.net/~cjwatson/launchpad/+git/launchpad/+merge/394702 for a verbose workaround that would be simpler with the aid of this patch (e.g. `POMsgID.msgid.contains_string(text, case_sensitive=False)`).

[Ioana Lasc (ilasc)]

review: Approve

=== modified file 'NEWS'
--- NEWS	2020-06-12 10:37:06 +0000
+++ NEWS	2020-12-07 22:43:51 +0000
@@ -1,3 +1,13 @@
+0.25
+====
+
+Improvements
+------------
+
+- Add optional case_sensitive argument to Comparable.startswith,
+  Comparable.endswith, and Comparable.contains_string.  This is only
+  supported in the PostgreSQL backend.
+
 0.24 (2020-06-12)
 =================
 
 
=== modified file 'storm/expr.py'
--- storm/expr.py	2020-02-10 15:30:23 +0000
+++ storm/expr.py	2020-12-07 22:43:51 +0000
@@ -517,23 +517,23 @@
     def upper(self):
         return Upper(self)
 
-    def startswith(self, prefix):
+    def startswith(self, prefix, case_sensitive=None):
         if not isinstance(prefix, six.text_type):
             raise ExprError("Expected text argument, got %r" % type(prefix))
         pattern = prefix.translate(like_escape) + u"%"
-        return Like(self, pattern, u"!")
+        return Like(self, pattern, u"!", case_sensitive)
 
-    def endswith(self, suffix):
+    def endswith(self, suffix, case_sensitive=None):
         if not isinstance(suffix, six.text_type):
             raise ExprError("Expected text argument, got %r" % type(suffix))
         pattern = u"%" + suffix.translate(like_escape)
-        return Like(self, pattern, u"!")
+        return Like(self, pattern, u"!", case_sensitive)
 
-    def contains_string(self, substring):
+    def contains_string(self, substring, case_sensitive=None):
         if not isinstance(substring, six.text_type):
             raise ExprError("Expected text argument, got %r" % type(substring))
         pattern = u"%" + substring.translate(like_escape) + u"%"
-        return Like(self, pattern, u"!")
+        return Like(self, pattern, u"!", case_sensitive)
 
 
 class ComparableExpr(Expr, Comparable):
 
=== modified file 'storm/tests/expr.py'
--- storm/tests/expr.py	2020-02-10 15:30:23 +0000
+++ storm/tests/expr.py	2020-12-07 22:43:51 +0000
@@ -199,6 +199,15 @@
         self.assertEqual(like_expr.expr2, u"abc!!!!!_!%%")
         self.assertEqual(like_expr.escape, u"!")
 
+    def test_startswith_case(self):
+        expr = Func1()
+        like_expr = expr.startswith(u"abc!!_%")
+        self.assertIsNone(like_expr.case_sensitive)
+        like_expr = expr.startswith(u"abc!!_%", case_sensitive=True)
+        self.assertIs(True, like_expr.case_sensitive)
+        like_expr = expr.startswith(u"abc!!_%", case_sensitive=False)
+        self.assertIs(False, like_expr.case_sensitive)
+
     def test_endswith(self):
         expr = Func1()
         self.assertRaises(ExprError, expr.startswith, b"not a unicode string")
@@ -209,6 +218,15 @@
         self.assertEqual(like_expr.expr2, u"%abc!!!!!_!%")
         self.assertEqual(like_expr.escape, u"!")
 
+    def test_endswith_case(self):
+        expr = Func1()
+        like_expr = expr.endswith(u"abc!!_%")
+        self.assertIsNone(like_expr.case_sensitive)
+        like_expr = expr.endswith(u"abc!!_%", case_sensitive=True)
+        self.assertIs(True, like_expr.case_sensitive)
+        like_expr = expr.endswith(u"abc!!_%", case_sensitive=False)
+        self.assertIs(False, like_expr.case_sensitive)
+
     def test_contains_string(self):
         expr = Func1()
         self.assertRaises(
@@ -220,6 +238,15 @@
         self.assertEqual(like_expr.expr2, u"%abc!!!!!_!%%")
         self.assertEqual(like_expr.escape, u"!")
 
+    def test_contains_string_case(self):
+        expr = Func1()
+        like_expr = expr.contains_string(u"abc!!_%")
+        self.assertIsNone(like_expr.case_sensitive)
+        like_expr = expr.contains_string(u"abc!!_%", case_sensitive=True)
+        self.assertIs(True, like_expr.case_sensitive)
+        like_expr = expr.contains_string(u"abc!!_%", case_sensitive=False)
+        self.assertIs(False, like_expr.case_sensitive)
+
     def test_eq(self):
         expr = Eq(elem1, elem2)
         self.assertEqual(expr.expr1, elem1)