Replace broken i18n shell test with Python test

We had been using shell scripts and sed to test our translations. But
trying to edit pot and po files with sed is nearly impossible because
the file format can vary significantly and the sed editing was failing
and gettext tools were complaining about our test strategy.  We had
been using a Python script (test_i18n.py) to perform the actual test
after using shell, sed, and gettext tools to create the files. There
is a Python library (polib) which can read/write/edit pot/po/mo files
(used internally by Transifex, our translation portal). The strategy
now is to do everything in Python (in test_i18n.py). This is easier,
more robust and allows us to do more things.

* add python-polib to BuildRequires

* Remove the logic for creating the test lang from Makefile.in and
  replace it with calls to test_i18n.py

* add argument parsing, usage, configuration parameters, etc. to
  test_i18n.py to make it easier to use and configurable.

* add function to generate a test po and mo file. It also
  writes the files and creates the test directory structure.

* Took the existing validate code and refactored it into validation
  function. It used to just pick one string and test it, now it
  iterates over all strings and all plural forms.

* Validate anonymous Python format substitutions in pot file

* added support for plural forms.

* Add pot po file validation for variable substitution

* In install/po subdir you can now do:
  $ make test
  $ make validate-pot
  $ make validate-po

* The options for running test_i18n.py are:

$ ./test_i18n.py --help
Usage:

test_i18n.py --test-gettext
test_i18n.py --create-test
test_i18n.py --validate-pot [pot_file1, ...]
test_i18n.py --validate-po po_file1 [po_file2, ...]

Options:
  -h, --help            show this help message and exit
  -s, --show-strings    show the offending string when an error is detected
  --pedantic            be aggressive when validating
  -v, --verbose         be informative
  --traceback           print the traceback when an exception occurs

  Operational Mode:
    You must select one these modes to run in

    -g, --test-gettext  create the test translation file(s) and exercise them
    -c, --create-test   create the test translation file(s)
    -P, --validate-pot  validate pot file(s)
    -p, --validate-po   validate po file(s)

  Run Time Parameters:
    These may be used to modify the run time defaults

    --test-lang=TEST_LANG
                        test po file uses this as it's basename (default=test)
    --lang=LANG         lang used for locale, MUST be a valid lang
                        (default=xh_ZA)
    --domain=DOMAIN     translation domain used during test (default=ipa)
    --locale=LOCALE     locale used during test (default=test_locale)
    --pot-file=POT_FILE
                        default pot file, used when validating pot file or
                        generating test po and mo files (default=ipa.pot)

https://fedorahosted.org/freeipa/ticket/2044

4 files changed, 576 insertions, 68 deletions

diff --git a/.gitignore b/.gitignore
index 14f9e9b6e..d20747c04 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,6 +46,8 @@ install/config.status
 install/install-sh
 install/missing
 install/stamp-h1
+install/po/test.po
+install/po/test_locale/xh_ZA/LC_MESSAGES/ipa.mo
 install/ui/test/results
 ipa-client/COPYING
 ipa-client/ChangeLog
diff --git a/freeipa.spec.in b/freeipa.spec.in
index a76a7b555..7e6bce78c 100644
--- a/freeipa.spec.in
+++ b/freeipa.spec.in
@@ -73,6 +73,7 @@ BuildRequires:  python-kerberos
 BuildRequires:  python-rhsm
 BuildRequires:  pyOpenSSL
 BuildRequires:  pylint
+BuildRequires:  python-polib
 BuildRequires:  libipa_hbac-python
 BuildRequires:  python-memcached
 BuildRequires:  sssd >= 1.8.0
diff --git a/install/po/Makefile.in b/install/po/Makefile.in
index 034884c63..4bee861a8 100644
--- a/install/po/Makefile.in
+++ b/install/po/Makefile.in
@@ -66,7 +66,7 @@ C_POTFILES = $(C_FILES) $(H_FILES)
 
 .SUFFIXES:
 .SUFFIXES: .po .mo
-.PHONY: all create-po update-po update-pot install mostlyclean clean distclean test_lang test mo-files debug
+.PHONY: all create-po update-po update-pot install mostlyclean clean distclean test mo-files debug
 
 all:
 
@@ -129,6 +129,7 @@ update-pot:
 	    echo "$(DOMAIN).pot unmodified" ; \
 	fi || :
 	@rm -f $(DOMAIN).pot.update $(DOMAIN).pot.update.tmp $(DOMAIN).pot.tmp
+	./test_i18n.py --show-strings --validate-pot $(DOMAIN).pot
 
 msg-stats:
 	@pot_count=`$(MSGFMT) --statistics $(DOMAIN).pot 2>&1 | \
@@ -192,17 +193,14 @@ maintainer-clean: distclean
 # msgstr will be set to the empty string (i.e. untranslated). We depend on
 # the msgid being copied to the msgstr.
 
-test_lang:
-	rm -rf test.po test_locale
-	$(MSGINIT) --no-translator -i $(DOMAIN).pot -l en_US -o test.po
-	$(SED) -i -r -e 's/Language: en_US/Language: xh_ZA/' test.po
-	$(SED) -i -r -e 's/^msgstr[ \t]+"(..*)"[ \t]*$$/msgstr "\xe2\x86\x92\1\xe2\x86\x90"/' test.po
-	$(SED) -i -r -e 's/^msgstr[ \t]+"(.*)(\\n)(.)"[ \t]*$$/msgstr "\1\xe2\x86\x90\2"/' test.po
-	$(MKDIR_P) test_locale/xh_ZA/LC_MESSAGES
-	$(MSGFMT) -o test_locale/xh_ZA/LC_MESSAGES/ipa.mo test.po
-
-test: test_lang
-	./test_i18n.py
+test:
+	./test_i18n.py --test-gettext
+
+validate-pot:
+	./test_i18n.py --show-strings --validate-pot $(DOMAIN).pot
+
+validate-po:
+	./test_i18n.py --show-strings --validate-po $(po_files)
 
 debug:
 	@echo Python potfiles:
diff --git a/install/po/test_i18n.py b/install/po/test_i18n.py
index 0797dd79f..beb43ccaa 100755
--- a/install/po/test_i18n.py
+++ b/install/po/test_i18n.py
@@ -19,91 +19,598 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
+import optparse
 import sys
 import gettext
 import locale
 import re
 import os
+import traceback
+import polib
 
-def get_msgid(po_file):
-    'Get the first non-empty msgid from the po file'
-    msgid_re = re.compile(r'^\s*msgid\s+"(.+)"\s*$')
-    f = open(po_file)
-    for line in f.readlines():
-        match = msgid_re.search(line)
-        if match:
-            msgid = match.group(1)
-            f.close()
-            return msgid
-    f.close()
-    raise ValueError('No msgid found in %s' % po_file)
-
-# We test our translations by taking the original untranslated string
-# (e.g. msgid) and prepend a prefix character and then append a suffix
-# character. The test consists of asserting that the first character in the
-# translated string is the prefix, the last character in the translated string
-# is the suffix and the everything between the first and last character exactly
-# matches the original msgid.
-#
-# We use unicode characters not in the ascii character set for the prefix and
-# suffix to enhance the test. To make reading the translated string easier the
-# prefix is the unicode right pointing arrow and the suffix left pointing arrow,
-# thus the translated string looks like the original string enclosed in
-# arrows. In ASCII art the string "foo" would render as:
-# -->foo<--
+'''
+We test our translations by taking the original untranslated string
+(e.g. msgid) and prepend a prefix character and then append a suffix
+character. The test consists of asserting that the first character in the
+translated string is the prefix, the last character in the translated string
+is the suffix and the everything between the first and last character exactly
+matches the original msgid.
+
+We use unicode characters not in the ascii character set for the prefix and
+suffix to enhance the test. To make reading the translated string easier the
+prefix is the unicode right pointing arrow and the suffix left pointing arrow,
+thus the translated string looks like the original string enclosed in
+arrows. In ASCII art the string "foo" would render as:
+-->foo<--
+'''
+
+#-------------------------------------------------------------------------------
+
+verbose = False
+print_traceback = False
+pedantic = False
+show_strings = True
 
 # Unicode right pointing arrow
 prefix = u'\u2192'               # utf-8 == '\xe2\x86\x92'
 # Unicode left pointing arrow
 suffix = u'\u2190'               # utf-8 == '\xe2\x86\x90'
 
-def main():
+page_width = 80
+section_seperator = '=' * page_width
+entry_seperator = '-' * page_width
+
+#-------------------------------------------------------------------------------
+# For efficiency compile these regexps just once
+_substitution_regexps = [re.compile(r'%[srduoxf]\b'),        # e.g. %s
+                         re.compile(r'%\(\w+\)[srduoxf]\b'), # e.g. %(foo)s
+                         re.compile(r'\$\w+'),               # e.g. $foo
+                         re.compile(r'\${\w+}'),             # e.g. ${foo}
+                         re.compile(r'\$\(\w+\)')            # e.g. $(foo)
+                         ]
+# Python style substitution, e.g. %(foo)s
+# where foo is the key and s is the format char
+# group 1: whitespace between % and (
+# group 2: whitespace between ( and key
+# group 3: whitespace between key and )
+# group 4: whitespace between ) and format char
+# group 5: format char
+_python_substitution_regexp = re.compile(r'%(\s*)\((\s*)\w+(\s*)\)(\s*)([srduoxf]\b)?')
+
+# Shell style substitution, e.g. $foo $(foo) ${foo}
+# where foo is the variable
+_shell_substitution_regexp = re.compile(r'\$(\s*)([({]?)(\s*)\w+(\s*)([)}]?)')
+# group 1: whitespace between $ and delimiter
+# group 2: begining delimiter
+# group 3: whitespace between beginning delmiter and variable
+# group 4: whitespace between variable and ending delimiter
+# group 5: ending delimiter
+
+# We do not permit anonymous substitutions in translation strings
+# (e.g. '%s occurred' % error) because they do not provide the
+# necessary context to translators, they would only see
+# '%s occurred'. Instead a keyword substitution should be used
+# (e.g. '%(error)s occurred' % {'error': error_message})
+
+# Python anonymous format substitutions, e.g. %s, %d, %f, etc.
+python_anonymous_substitutions_regexp = re.compile(r'%[srduoxf]\b') # e.g. %s
+
+def validate_substitutions_match(s1, s2, s1_name='string1', s2_name='string2'):
+    '''
+    Validate both s1 and s2 have the same number of substitution strings.
+    A substitution string would be something that looked like this:
+
+    * %(foo)s
+    * $foo
+    * ${foo}
+    * $(foo)
+
+    The substitutions may appear in any order in s1 and s2, however their
+    format must match exactly and the exact same number of each must exist
+    in both s1 and s2.
+
+    A list of error diagnostics is returned explaining how s1 and s2 failed
+    the validation check. If the returned error list is empty then the
+    validation succeeded.
+
+    :param s1:      First string to validate
+    :param s2:      First string to validate
+    :param s1_name: In diagnostic messages the name for s1
+    :param s2_name: In diagnostic messages the name for s2
+    :return:        List of diagnostic error messages, if empty then success
+    '''
+    errors = []
+
+    def get_subs(s):
+        '''
+        Return a dict whoses keys are each unique substitution and whose
+        value is the count of how many times that substitution appeared.
+        '''
+        subs = {}
+        for regexp in _substitution_regexps:
+            for match in regexp.finditer(s):
+                matched = match.group(0)
+                subs[matched] = subs.get(matched, 0) + 1
+        return subs
+
+    # Get the substitutions and their occurance counts
+    subs1 = get_subs(s1)
+    subs2 = get_subs(s2)
+
+    # Form a set for each strings substitutions and
+    # do set subtraction and interesection
+    set1 = set(subs1.keys())
+    set2 = set(subs2.keys())
+
+    missing1 = set2 - set1
+    missing2 = set1 - set2
+    common = set1 & set2
+
+    # Test for substitutions which are absent in either string
+    if missing1:
+        errors.append("The following substitutions are absent in %s: %s" %
+                      (s1_name, ' '.join(missing1)))
+
+    if missing2:
+        errors.append("The following substitutions are absent in %s: %s" %
+                      (s2_name, ' '.join(missing2)))
+
+    if pedantic:
+        # For the substitutions which are shared assure they occur an equal number of times
+        for sub in common:
+            if subs1[sub] != subs2[sub]:
+                errors.append("unequal occurances of '%s', %s has %d occurances, %s has %d occurances" %
+                              (sub, s1_name, subs1[sub], s2_name, subs2[sub]))
+
+    if errors:
+        if show_strings:
+            errors.append('>>> %s <<<' % s1_name)
+            errors.append(s1.rstrip())
+
+            errors.append('>>> %s <<<' % s2_name)
+            errors.append(s2.rstrip())
+    return errors
+
+
+def validate_substitution_syntax(s, s_name='string'):
+    '''
+    If s has one or more substitution variables then validate they
+    are syntactically correct.
+    A substitution string would be something that looked like this:
+
+    * %(foo)s
+    * $foo
+    * ${foo}
+    * $(foo)
+
+    A list of error diagnostics is returned explaining how s1 and s2 failed
+    the validation check. If the returned error list is empty then the
+    validation succeeded.
+
+    :param s:      String to validate
+    :param s_name: In diagnostic messages the name for s
+    :return:       List of diagnostic error messages, if empty then success
+    '''
+    errors = []
+
+    # Look for Python style substitutions, e.g. %(foo)s
+    for match in _python_substitution_regexp.finditer(s):
+        if match.group(1):
+            errors.append("%s has whitespace between %% and key in '%s'" %
+                          (s_name, match.group(0)))
+        if match.group(2) or match.group(3):
+            errors.append("%s has whitespace next to key in '%s'" %
+                          (s_name, match.group(0)))
+        if match.group(4):
+            errors.append("%s has whitespace between key and format character in '%s'" %
+                          (s_name, match.group(0)))
+        if not match.group(5):
+            errors.append("%s has no format character in '%s'" %
+                          (s_name, match.group(0)))
+
+    # Look for shell style substitutions, e.g. $foo $(foo) ${foo}
+    for match in _shell_substitution_regexp.finditer(s):
+        if match.group(1):
+            errors.append("%s has whitespace between $ and variable in '%s'" %
+                          (s_name, match.group(0)))
+        if match.group(3) or (match.group(4) and match.group(5)):
+            errors.append("%s has whitespace next to variable in '%s'" %
+                          (s_name, match.group(0)))
+
+        beg_delimiter = match.group(2)
+        end_delimiter = match.group(5)
+        matched_delimiters = {'': '', '(': ')', '{': '}'}
+        if beg_delimiter is not None or end_delimiter is not None:
+            if matched_delimiters[beg_delimiter] != end_delimiter:
+                errors.append("%s variable delimiters do not match in '%s', begin delimiter='%s' end delimiter='%s'" %
+                              (s_name, match.group(0), beg_delimiter, end_delimiter))
+
+    if errors:
+        if show_strings:
+            errors.append('>>> %s <<<' % s_name)
+            errors.append(s.rstrip())
+
+    return errors
+
+
+def validate_anonymous_substitutions(s, s_name='string'):
+    '''
+    We do not permit multiple anonymous substitutions in translation
+    strings (e.g. '%s') because they do not allow translators to reorder the
+    wording. Instead keyword substitutions should be used when there are
+    more than one.
+    '''
+    errors = []
+
+
+    matches = list(python_anonymous_substitutions_regexp.finditer(s))
+
+    if len(matches) > 1:
+        for match in python_anonymous_substitutions_regexp.finditer(s):
+            errors.append("%s has anonymous substitution '%s', use keyword substitution instead" %
+                          (s_name, match.group(0)))
+
+    if errors:
+        if show_strings:
+            errors.append('>>> %s <<<' % s_name)
+            errors.append(s.rstrip())
+
+    return errors
+
+def validate_file(file_path, validation_mode):
+    '''
+    Given a pot or po file scan all it's entries looking for problems
+    with variable substitutions. See the following functions for
+    details on how the validation is performed.
+
+    * validate_substitutions_match()
+    * validate_substitution_syntax()
+    * validate_anonymous_substitutions()
+
+    Returns the number of entries with errors.
+    '''
+
+    error_lines = []
+    n_entries_with_errors = 0
+
+    if not os.path.isfile(file_path):
+        print >>sys.stderr, 'file does not exist "%s"' % (file_path)
+        return 1
+    try:
+        po = polib.pofile(file_path)
+    except Exception, e:
+        print >>sys.stderr, 'Unable to parse file "%s": %s' % (file_path, e)
+        return 1
+
+    for entry in po:
+        entry_errors = []
+        msgid = entry.msgid
+        msgstr = entry.msgstr
+        have_msgid = msgid.strip() != ''
+        have_msgstr = msgstr.strip() != ''
+        if validation_mode == 'pot':
+            if have_msgid:
+                errors = validate_anonymous_substitutions(msgid, 'msgid')
+                entry_errors.extend(errors)
+        if validation_mode == 'po':
+            if have_msgid and have_msgstr:
+                errors = validate_substitutions_match(msgid, msgstr, 'msgid', 'msgstr')
+                entry_errors.extend(errors)
+        if pedantic:
+            if have_msgid:
+                errors = validate_substitution_syntax(msgid, 'msgid')
+                entry_errors.extend(errors)
+            if have_msgstr:
+                errors = validate_substitution_syntax(msgstr, 'msgstr')
+                entry_errors.extend(errors)
+        if entry_errors:
+            error_lines.append(entry_seperator)
+            error_lines.append('locations: %s' % (', '.join(["%s:%d" % (x[0], int(x[1])) for x in entry.occurrences])))
+            error_lines.extend(entry_errors)
+            n_entries_with_errors += 1
+    if n_entries_with_errors:
+        error_lines.insert(0, section_seperator)
+        error_lines.insert(1, "%d validation errors in %s" % (n_entries_with_errors, file_path))
+        print '\n'.join(error_lines)
+
+    return n_entries_with_errors
+
+
+#----------------------------------------------------------------------
+def create_po(pot_file, po_file, mo_file):
+
+    if not os.path.isfile(pot_file):
+        print >>sys.stderr, 'file does not exist "%s"' % (pot_file)
+        return 1
+    try:
+        po = polib.pofile(pot_file)
+    except Exception, e:
+        print >>sys.stderr, 'Unable to parse file "%s": %s' % (pot_file, e)
+        return 1
+
+    # Update the metadata in the po file header
+    # It's case insensitive so search the keys in a case insensitive manner
+    #
+    # We need to update the Plural-Forms otherwise gettext.py will raise the
+    # following error:
+    #
+    # raise ValueError, 'plural forms expression could be dangerous'
+    #
+    # It is demanding the rhs of plural= only contains the identifer 'n'
+
+    for k,v in po.metadata.items():
+        if k.lower() == 'plural-forms':
+            po.metadata[k] = 'nplurals=2; plural=(n != 1)'
+            break
+
+
+    # Iterate over all msgid's and form a the msgstr by prepending
+    # the prefix and appending the suffix
+    for entry in po:
+        if entry.msgid_plural:
+            entry.msgstr_plural = {0: prefix + entry.msgid + suffix,
+                                   1: prefix + entry.msgid_plural + suffix}
+        else:
+            entry.msgstr = prefix + entry.msgid + suffix
+
+    # Write out the po and mo files
+    po.save(po_file)
+    print "Wrote: %s" % (po_file)
+
+    po.save_as_mofile(mo_file)
+    print "Wrote: %s" % (mo_file)
+
+    return 0
+
+#----------------------------------------------------------------------
+
+def validate_unicode_edit(msgid, msgstr):
+    # Verify the first character is the test prefix
+    if msgstr[0] != prefix:
+        raise ValueError('First char in translated string "%s" not equal to prefix "%s"' %
+                         (msgstr.encode('utf-8'), prefix.encode('utf-8')))
+
+    # Verify the last character is the test suffix
+    if msgstr[-1] != suffix:
+        raise ValueError('Last char in translated string "%s" not equal to suffix "%s"' %
+                         (msgstr.encode('utf-8'), suffix.encode('utf-8')))
 
-    test_file = 'test.po'
+    # Verify everything between the first and last character is the
+    # original untranslated string
+    if msgstr[1:-1] != msgid:
+        raise ValueError('Translated string "%s" minus the first & last character is not equal to msgid "%s"' %
+                         (msgstr.encode('utf-8'), msgid))
 
+    if verbose:
+        msg = 'Success: message string "%s" maps to translated string "%s"' % (msgid, msgstr)
+        print msg.encode('utf-8')
+
+
+def test_translations(po_file, lang, domain, locale_dir):
     try:
 
-        # The test installs the test message catalog under the xh_ZA (e.g. Zambia Xhosa)
-        # language. It would be nice to use a dummy language not associated with any
-        # real language, but the setlocale function demands the locale be a valid known
-        # locale, Zambia Xhosa is a reasonable choice :)
-        os.environ['LANG'] = 'xh_ZA'
+        # The test installs the test message catalog under the xh_ZA
+        # (e.g. Zambia Xhosa) language by default. It would be nice to
+        # use a dummy language not associated with any real language,
+        # but the setlocale function demands the locale be a valid
+        # known locale, Zambia Xhosa is a reasonable choice :)
+
+        os.environ['LANG'] = lang
+
+        # Create a gettext translation object specifying our domain as
+        # 'ipa' and the locale_dir as 'test_locale' (i.e. where to
+        # look for the message catalog). Then use that translation
+        # object to obtain the translation functions.
 
-        # Tell gettext that our domain is 'ipa', that locale_dir is 'test_locale'
-        # (i.e. where to look for the message catalog) and that we want the translations
-        # returned as unicode from the _() function
-        gettext.install('ipa', 'test_locale', unicode=1)
+        t = gettext.translation(domain, locale_dir)
 
-        # We need a translatable string to test with, read one from the test po file
-        msgid = get_msgid(test_file)
+        # Iterate over the msgid's
+        if not os.path.isfile(po_file):
+            print >>sys.stderr, 'file does not exist "%s"' % (po_file)
+            return 1
+        try:
+            po = polib.pofile(po_file)
+        except Exception, e:
+            print >>sys.stderr, 'Unable to parse file "%s": %s' % (po_file, e)
+            return 1
 
-        print "Using message string \"%s\" found in file \"%s\"" % (msgid, test_file)
+        n_entries = 0
+        n_translations = 0
+        n_valid = 0
+        n_fail = 0
+        for entry in po:
+            if entry.msgid_plural:
+                msgid = entry.msgid
+                msgid_plural = entry.msgid_plural
+                msgstr = t.ungettext(msgid, msgid_plural, 1)
+                msgstr_plural = t.ungettext(msgid, msgid_plural, 2)
 
-        # Get the translated version of the msgid string by invoking _()
-        translated = _(msgid)   #pylint: disable=E0602
+                try:
+                    n_translations += 1
+                    validate_unicode_edit(msgid, msgstr)
+                    n_valid += 1
+                except Exception, e:
+                    n_fail += 1
+                    if print_traceback:
+                        traceback.print_exc()
+                    print >> sys.stderr, "ERROR: %s" % e
 
-        # Verify the first character is the test prefix
-        if translated[0] != prefix:
-            raise ValueError("First char in translated string \"%s\" not equal to prefix \"%s\"" % \
-                                 (translated.encode('utf-8'), prefix.encode('utf-8')))
+                try:
+                    n_translations += 1
+                    validate_unicode_edit(msgid_plural, msgstr_plural)
+                    n_valid += 1
+                except Exception, e:
+                    n_fail += 1
+                    if print_traceback:
+                        traceback.print_exc()
+                    print >> sys.stderr, "ERROR: %s" % e
 
-        # Verify the last character is the test suffix
-        if translated[-1] != suffix:
-            raise ValueError("Last char in translated string \"%s\" not equal to suffix \"%s\"" % \
-                                 (translated.encode('utf-8'), suffix.encode('utf-8')))
 
-        # Verify everything between the first and last character is the
-        # original untranslated string
-        if translated[1:-1] != msgid:
-            raise ValueError("Translated string \"%s\" minus the first & last character is not equal to msgid \"%s\"" % \
-                                 (translated.encode('utf-8'), msgid))
+            else:
+                msgid = entry.msgid
+                msgstr = t.ugettext(msgid)
+
+                try:
+                    n_translations += 1
+                    validate_unicode_edit(msgid, msgstr)
+                    n_valid += 1
+                except Exception, e:
+                    n_fail += 1
+                    if print_traceback:
+                        traceback.print_exc()
+                    print >> sys.stderr, "ERROR: %s" % e
+
+            n_entries += 1
 
-        print "Success: message string \"%s\" maps to translated string \"%s\"" % (msgid, _(msgid).encode('utf-8')) #pylint: disable=E0602
     except Exception, e:
+        if print_traceback:
+            traceback.print_exc()
         print >> sys.stderr, "ERROR: %s" % e
         return 1
 
+    if not n_entries:
+        print >> sys.stderr, "ERROR: no translations found in %s" % (po_filename)
+        return 1
+
+    if n_fail:
+        print >> sys.stderr, "ERROR: %d failures out of %d translations" % (n_fail, n_entries)
+        return 1
+
+    print "%d translations in %d messages successfully tested" % (n_translations, n_entries)
     return 0
 
+#----------------------------------------------------------------------
+
+usage ='''
+
+%prog --test-gettext
+%prog --create-test
+%prog --validate-pot [pot_file1, ...]
+%prog --validate-po po_file1 [po_file2, ...]
+'''
+
+def main():
+    global verbose, print_traceback, pedantic, show_strings
+
+    parser = optparse.OptionParser(usage=usage)
+
+    mode_group = optparse.OptionGroup(parser, 'Operational Mode',
+                                      'You must select one these modes to run in')
+
+    mode_group.add_option('-g', '--test-gettext', action='store_const', const='test_gettext', dest='mode',
+                          help='create the test translation file(s) and exercise them')
+    mode_group.add_option('-c', '--create-test', action='store_const', const='create_test', dest='mode',
+                          help='create the test translation file(s)')
+    mode_group.add_option('-P', '--validate-pot', action='store_const', const='validate_pot', dest='mode',
+                          help='validate pot file(s)')
+    mode_group.add_option('-p', '--validate-po', action='store_const', const='validate_po', dest='mode',
+                          help='validate po file(s)')
+
+    parser.add_option_group(mode_group)
+    parser.set_defaults(mode='')
+
+    parser.add_option('-s', '--show-strings', action='store_true', dest='show_strings', default=False,
+                      help='show the offending string when an error is detected')
+    parser.add_option('--pedantic', action='store_true', dest='pedantic', default=False,
+                      help='be aggressive when validating')
+    parser.add_option('-v', '--verbose', action='store_true', dest='verbose', default=False,
+                      help='be informative')
+    parser.add_option('--traceback', action='store_true', dest='print_traceback', default=False,
+                      help='print the traceback when an exception occurs')
+
+    param_group = optparse.OptionGroup(parser, 'Run Time Parameters',
+                                       'These may be used to modify the run time defaults')
+
+    param_group.add_option('--test-lang', action='store', dest='test_lang', default='test',
+                           help="test po file uses this as it's basename (default=test)")
+    param_group.add_option('--lang', action='store', dest='lang', default='xh_ZA',
+                           help='lang used for locale, MUST be a valid lang (default=xh_ZA)')
+    param_group.add_option('--domain', action='store', dest='domain', default='ipa',
+                           help='translation domain used during test (default=ipa)')
+    param_group.add_option('--locale-dir', action='store', dest='locale_dir', default='test_locale',
+                           help='locale directory used during test (default=test_locale)')
+    param_group.add_option('--pot-file', action='store', dest='pot_file', default='ipa.pot',
+                           help='default pot file, used when validating pot file or generating test po and mo files (default=ipa.pot)')
+
+    parser.add_option_group(param_group)
+
+    options, args = parser.parse_args()
+
+    verbose = options.verbose
+    print_traceback = options.print_traceback
+    pedantic = options.pedantic
+    show_strings = options.show_strings
+
+    if not options.mode:
+        print >> sys.stderr, 'ERROR: no mode specified'
+        return 1
+
+    if options.mode == 'validate_pot' or options.mode == 'validate_po':
+        if options.mode == 'validate_pot':
+            files = args
+            if not files:
+                files = [options.pot_file]
+            validation_mode = 'pot'
+        elif options.mode == 'validate_po':
+            files = args
+            if not files:
+                print >> sys.stderr, 'ERROR: no po files specified'
+                return 1
+            validation_mode = 'po'
+        else:
+            print >> sys.stderr, 'ERROR: unknown validation mode "%s"' % (options.mode)
+            return 1
+
+        total_errors = 0
+        for f in files:
+            n_errors = validate_file(f, validation_mode)
+            total_errors += n_errors
+        if total_errors:
+            print section_seperator
+            print "%d errors in %d files" % (total_errors, len(files))
+            return 1
+        else:
+            return 0
+
+    elif options.mode == 'create_test' or 'test_gettext':
+        po_file = '%s.po' % options.test_lang
+        pot_file = options.pot_file
+
+        msg_dir = os.path.join(options.locale_dir, options.lang, 'LC_MESSAGES')
+        if not os.path.exists(msg_dir):
+            os.makedirs(msg_dir)
+
+        mo_basename = '%s.mo' % options.domain
+        mo_file = os.path.join(msg_dir, mo_basename)
+
+        result = create_po(pot_file, po_file, mo_file)
+        if result:
+            return result
+
+        if options.mode == 'create_test':
+            return result
+
+        # The test installs the test message catalog under the xh_ZA
+        # (e.g. Zambia Xhosa) language by default. It would be nice to
+        # use a dummy language not associated with any real language,
+        # but the setlocale function demands the locale be a valid
+        # known locale, Zambia Xhosa is a reasonable choice :)
+
+        lang = options.lang
+
+        # Create a gettext translation object specifying our domain as
+        # 'ipa' and the locale_dir as 'test_locale' (i.e. where to
+        # look for the message catalog). Then use that translation
+        # object to obtain the translation functions.
+
+        domain = options.domain
+        locale_dir = options.locale_dir
+
+        return test_translations(po_file, lang, domain, locale_dir)
+
+    else:
+        print >> sys.stderr, 'ERROR: unknown mode "%s"' % (options.mode)
+        return 1
+
 if __name__ == "__main__":
     sys.exit(main())