Add a test that validates that the .po and .mo files match for all active languages

i18n/tests/test_compiled_messages.py

@@ -0,0 +1,59 @@
+"""
+Test that the compiled .mo files match the translations in the
+uncompiled .po files.
+
+This is required because we are checking in the .mo files into
+the repo, but compiling them is a manual process. We want to make
+sure that we find out if someone forgets the compilation step.
+"""
+
+import ddt
+import polib
+from unittest import TestCase
+
+from i18n.config import CONFIGURATION, LOCALE_DIR
+
+
+@ddt.ddt
+class TestCompiledMessages(TestCase):
+    """
+    Test that mo files match their source po files
+    """
+
+    PO_FILES = ['django.po', 'djangojs.po']
+
+    @ddt.data(*CONFIGURATION.locales)
+    def test_translated_messages(self, locale):
+        message_dir = LOCALE_DIR / locale / 'LC_MESSAGES'
+        for pofile_name in self.PO_FILES:
+            pofile_path = message_dir / pofile_name
+            pofile = polib.pofile(pofile_path)
+            mofile = polib.mofile(pofile_path.stripext() + '.mo')
+
+            po_entries = {entry.msgid: entry for entry in pofile.translated_entries()}
+            mo_entries = {entry.msgid: entry for entry in mofile.translated_entries()}
+
+            # Check that there are no entries in po that aren't in mo, and vice-versa
+            self.assertEquals(po_entries.viewkeys(), mo_entries.viewkeys())
+
+            for entry_id, po_entry in po_entries.iteritems():
+                mo_entry = mo_entries[entry_id]
+                for attr in ('msgstr', 'msgid_plural', 'msgstr_plural', 'msgctxt', 'obsolete', 'encoding'):
+                    po_attr = getattr(po_entry, attr)
+                    mo_attr = getattr(mo_entry, attr)
+
+                    # The msgstr_plural in the mo_file is keyed on ints, but in the po_file it's
+                    # keyed on strings. This normalizes them.
+                    if attr == 'msgstr_plural':
+                        po_attr = {int(key): val for (key, val) in po_attr.items()}
+
+                    self.assertEquals(
+                        po_attr,
+                        mo_attr,
+                        "When comparing {} for entry {!r}, {!r} from the .po file doesn't match {!r} from the .mo file".format(
+                            attr,
+                            entry_id,
+                            po_attr,
+                            mo_attr,
+                        )
+                    )