Merge lp:~danilo/launchpad/bug-531831 into lp:launchpad/db-devel

[Данило Шеган]

Show zero among examples of potential candidates for plural form expressions.

= Bug 531831 =

Do not forget about zero when showing a nice set of examples for plural forms.

Also provides more unit testing and extends catching of errors.

bin/test -vvt pluralforms

= Launchpad lint =

Checking for conflicts. and issues in doctests and templates.
Running jslint, xmllint, pyflakes, and pylint.
Using normal rules.

Linting changed files:
  lib/lp/translations/utilities/pluralforms.py
  lib/lp/translations/utilities/doc/pluralforms.txt
  lib/lp/translations/utilities/tests/test_pluralforms.py

[Henning Eggers (henninge)]

Thanks for the thorough fix.

review: Approve (code)

=== modified file 'lib/lp/translations/browser/tests/language-views.txt'
--- lib/lp/translations/browser/tests/language-views.txt	2009-12-03 15:14:55 +0000
+++ lib/lp/translations/browser/tests/language-views.txt	2010-03-05 14:13:43 +0000
@@ -93,7 +93,7 @@
     ...     print form_dict['form'], ':', form_dict['examples']
     0 : 1, 21, 31, 41, 51, 61...
     1 : 2, 3, 4, 22, 23, 24...
-    2 : 5, 6, 7, 8, 9, 10...
+    2 : 0, 5, 6, 7, 8, 9...
 
 View LanguageSet
 ------------------
 
=== modified file 'lib/lp/translations/stories/standalone/xx-language.txt'
--- lib/lp/translations/stories/standalone/xx-language.txt	2009-12-18 20:05:08 +0000
+++ lib/lp/translations/stories/standalone/xx-language.txt	2010-03-05 14:13:43 +0000
@@ -117,7 +117,7 @@
     Plural forms
     Spanish has 2 plural forms:
     Form 0 for 1.
-    Form 1 for 2, 3, 4, 5, 6, 7...
+    Form 1 for 0, 2, 3, 4, 5, 6...
     When ...
 
     >>> translationteams_portlet = find_portlet(
 
=== modified file 'lib/lp/translations/utilities/doc/pluralforms.txt'
--- lib/lp/translations/utilities/doc/pluralforms.txt	2009-09-16 02:35:32 +0000
+++ lib/lp/translations/utilities/doc/pluralforms.txt	2010-03-05 14:13:43 +0000
@@ -31,4 +31,4 @@
     ...     print form_dict['form'], ":", form_dict['examples']
     0 : [1, 21, 31, 41, 51, 61]
     1 : [2, 3, 4, 22, 23, 24]
-    2 : [5, 6, 7, 8, 9, 10]
+    2 : [0, 5, 6, 7, 8, 9]
 
=== modified file 'lib/lp/translations/utilities/pluralforms.py'
--- lib/lp/translations/utilities/pluralforms.py	2009-09-16 02:35:32 +0000
+++ lib/lp/translations/utilities/pluralforms.py	2010-03-05 14:13:43 +0000
@@ -19,8 +19,13 @@
     # The max length of the examples list per plural form.
     MAX_EXAMPLES = 6
 
-    for number in range(1, 200):
-        form = expression(number)
+    for number in range(0, 200):
+        try:
+            form = expression(number)
+        except ZeroDivisionError:
+            raise BadPluralExpression(
+                "Zero division error in the plural form expression.")
+
         # Create empty list if this form doesn't have one yet
         forms.setdefault(form, [])
         # If all the plural forms for this language have examples (max. of 6
@@ -29,6 +34,11 @@
             continue
         forms[form].append(number)
 
+    if pluralforms_count != len(forms):
+        raise BadPluralExpression(
+            "Number of recognized plural forms doesn't match the "
+            "expected number of them.")
+
     # Each dict has two keys, 'form' and 'examples', that address the form
     # number index and a list of its examples.
     return [{'form' : form, 'examples' : examples}
 
=== added file 'lib/lp/translations/utilities/tests/test_pluralforms.py'
--- lib/lp/translations/utilities/tests/test_pluralforms.py	1970-01-01 00:00:00 +0000
+++ lib/lp/translations/utilities/tests/test_pluralforms.py	2010-03-05 14:13:43 +0000
@@ -0,0 +1,59 @@
+# Copyright 2009 Canonical Ltd.  This software is licensed under the
+# GNU Affero General Public License version 3 (see the file LICENSE).
+
+import unittest
+
+from lp.translations.utilities.pluralforms import (
+    BadPluralExpression,
+    make_friendly_plural_forms)
+
+class PluralFormsTest(unittest.TestCase):
+    """Test utilities for handling plural forms."""
+
+    def test_make_friendly_plural_form(self):
+        single_form = make_friendly_plural_forms('0', 1)
+        self.assertEqual(single_form,
+                         [{'examples': [0, 1, 2, 3, 4, 5], 'form': 0}])
+
+        two_forms = make_friendly_plural_forms('n!=1', 2)
+        self.assertEqual(two_forms,
+                         [{'examples': [1], 'form': 0},
+                          {'examples': [0, 2, 3, 4, 5, 6], 'form': 1}])
+
+    def test_make_friendly_plural_form_failures(self):
+        # 'To the degree of' is not accepted.
+        self.assertRaises(BadPluralExpression,
+                          make_friendly_plural_forms, 'n**2', 1)
+
+        # Expressions longer than 500 characters are not accepted.
+        self.assertRaises(BadPluralExpression,
+                          make_friendly_plural_forms, '1'*501, 1)
+
+        # Using arbitrary variable names is not allowed.
+        self.assertRaises(BadPluralExpression,
+                          make_friendly_plural_forms, '(a=1)', 1)
+
+        # If number of actual forms doesn't match requested number.
+        self.assertRaises(BadPluralExpression,
+                          make_friendly_plural_forms, 'n!=1', 3)
+
+        # Dividing by zero doesn't work.
+        self.assertRaises(BadPluralExpression,
+                          make_friendly_plural_forms, '(n/0)', 1)
+
+    def test_make_friendly_plural_form_zero_handling(self):
+        zero_forms = make_friendly_plural_forms('n!=0', 2)
+        self.assertEqual(zero_forms,
+                         [{'examples': [0], 'form': 0},
+                          {'examples': [1, 2, 3, 4, 5, 6], 'form': 1}])
+
+        # Since 'n' can be zero as well, dividing by it won't work.
+        self.assertRaises(BadPluralExpression,
+                          make_friendly_plural_forms, '(1/n)', 1)
+
+
+def test_suite():
+    suite = unittest.TestSuite()
+    suite.addTest(unittest.makeSuite(PluralFormsTest))
+    return suite
+