Improve i18n_tool.py list-translators, update-from-weblate

Allow the specification of a commit whose timestamp will be used as
the starting point for gathering translator credits, instead of
starting from the last commit that says "l10n: sync". That breaks
badly if there are any source string changes during the release cycle
that require another sync, so instead, just examine all the commits
since the time of the specified revision, defaulting to the last
release tag.

Also, instead of always gathering translator contributions up to the
tip of i18n/i18n for list-translators and update-from-weblate, allow
the specification of a commit. This is intended to allow verification
of these functions' results; release management tasks should use the
default target of the i18n/i18n branch tip.

Author: rmol

securedrop/i18n_tool.py

@@ -13,7 +13,6 @@
 import textwrap
 from argparse import _SubParsersAction
 from typing import Optional
-from typing import Union
 
 from typing import Set
 
@@ -30,7 +29,6 @@
 
 
 class I18NTool:
-
     #
     # The database of support language, indexed by the language code
     # used by weblate (i.e. whatever shows as CODE in
@@ -41,7 +39,7 @@ class I18NTool:
     #       display in the interface.
     # desktop: The language code used for dekstop icons.
     #
-    SUPPORTED_LANGUAGES = {
+    supported_languages = {
         'ar': {'name': 'Arabic', 'desktop': 'ar', },
         'ca': {'name': 'Catalan', 'desktop': 'ca', },
         'cs': {'name': 'Czech', 'desktop': 'cs', },
@@ -62,12 +60,18 @@ class I18NTool:
         'tr': {'name': 'Turkish', 'desktop': 'tr', },
         'zh_Hant': {'name': 'Chinese, Traditional', 'desktop': 'zh_Hant', },
     }
+    release_tag_re = re.compile(r"^\d+\.\d+\.\d+$")
+    translated_commit_re = re.compile('Translated using Weblate')
+    updated_commit_re = re.compile(r'(?:updated from|  (?:revision|commit):) (\w+)')
 
-    def file_is_modified(self, path: str) -> int:
-        dir = dirname(path)
-        return subprocess.call(['git', '-C', dir, 'diff', '--quiet', path])
+    def file_is_modified(self, path: str) -> bool:
+        return bool(subprocess.call(['git', '-C', dirname(path), 'diff', '--quiet', path]))
 
     def ensure_i18n_remote(self, args: argparse.Namespace) -> None:
+        """
+        Make sure we have a git remote for the i18n repo.
+        """
+
         k = {'_cwd': args.root}
         if b'i18n' not in git.remote(**k).stdout:
             git.remote.add('i18n', args.url, **k)
@@ -219,7 +223,7 @@ def require_git_email_name(git_dir: str) -> bool:
 
     def update_docs(self, args: argparse.Namespace) -> None:
         l10n_content = u'.. GENERATED BY i18n_tool.py DO NOT EDIT:\n\n'
-        for (code, info) in sorted(I18NTool.SUPPORTED_LANGUAGES.items()):
+        for (code, info) in sorted(self.supported_languages.items()):
             l10n_content += '* ' + info['name'] + ' (``' + code + '``)\n'
         includes = abspath(join(args.docs_repo_dir, 'docs/includes'))
         l10n_txt = join(includes, 'l10n.txt')
@@ -246,73 +250,90 @@ def set_update_docs_parser(self, subps: _SubParsersAction) -> None:
         parser.set_defaults(func=self.update_docs)
 
     def update_from_weblate(self, args: argparse.Namespace) -> None:
+        """
+        Pull in updated translations from the i18n repo.
+        """
         self.ensure_i18n_remote(args)
-        codes = list(I18NTool.SUPPORTED_LANGUAGES.keys())
+        codes = list(self.supported_languages.keys())
         if args.supported_languages:
             codes = args.supported_languages.split(',')
         for code in sorted(codes):
-            info = I18NTool.SUPPORTED_LANGUAGES[code]
+            info = self.supported_languages[code]
 
-            def need_update(p: str) -> Union[bool, int]:
-                exists = os.path.exists(join(args.root, p))
+            def need_update(path: str) -> bool:
+                """
+                Check if the file is different in the i18n repo.
+                """
+
+                exists = os.path.exists(join(args.root, path))
                 k = {'_cwd': args.root}
-                git.checkout('i18n/i18n', '--', p, **k)
-                git.reset('HEAD', '--', p, **k)
+                git.checkout(args.target, '--', path, **k)
+                git.reset('HEAD', '--', path, **k)
                 if not exists:
                     return True
-                else:
-                    return self.file_is_modified(join(args.root, p))
 
-            def add(p: str) -> None:
-                git('-C', args.root, 'add', p)
+                return self.file_is_modified(join(args.root, path))
+
+            def add(path: str) -> None:
+                """
+                Add the file to the git index.
+                """
+                git('-C', args.root, 'add', path)
 
             updated = False
             #
-            # Update messages
+            # Add changes to web .po files
             #
-            p = "securedrop/translations/{l}/LC_MESSAGES/messages.po".format(
+            path = "securedrop/translations/{l}/LC_MESSAGES/messages.po".format(
                 l=code)  # noqa: E741
-            if need_update(p):
-                add(p)
+            if need_update(path):
+                add(path)
                 updated = True
             #
-            # Update desktop
+            # Add changes to desktop .po files
             #
             desktop_code = info['desktop']
-            p = join("install_files/ansible-base/roles",
+            path = join("install_files/ansible-base/roles",
                      "tails-config/templates/{l}.po".format(
                          l=desktop_code))  # noqa: E741
-            if need_update(p):
-                add(p)
+            if need_update(path):
+                add(path)
                 updated = True
 
             if updated:
-                self.upstream_commit(args, code)
+                self.commit_changes(args, code)
 
-    def translators(self, args: argparse.Namespace, path: str, commit_range: str) -> Set[str]:
+    def translators(self, args: argparse.Namespace, path: str, since: str) -> Set[str]:
         """
         Return the set of people who've modified a file in Weblate.
 
         Extracts all the authors of translation changes to the given
-        path in the given commit range. Translation changes are
+        path since the given timestamp. Translation changes are
         identified by the presence of "Translated using Weblate" in
         the commit message.
         """
-        translation_re = re.compile('Translated using Weblate')
 
-        path_changes = git(
-            '--no-pager', '-C', args.root,
-            'log', '--format=%aN\x1e%s', commit_range, '--', path,
-            _encoding='utf-8'
-        )
+        if since:
+            path_changes = git(
+                '--no-pager', '-C', args.root,
+                'log', '--format=%aN\x1e%s', '--since', since, args.target, '--', path,
+                _encoding='utf-8'
+            )
+        else:
+            path_changes = git(
+                '--no-pager', '-C', args.root,
+                'log', '--format=%aN\x1e%s', args.target, '--', path,
+                _encoding='utf-8'
+            )
         path_changes = u"{}".format(path_changes)
         path_changes = [c.split('\x1e') for c in path_changes.strip().split('\n')]
-        path_changes = [c for c in path_changes if len(c) > 1 and translation_re.match(c[1])]
-
+        path_changes = [
+            c for c in path_changes if len(c) > 1 and self.translated_commit_re.match(c[1])
+        ]
         path_authors = [c[0] for c in path_changes]
         return set(path_authors)
 
-    def upstream_commit(self, args: argparse.Namespace, code: str) -> None:
+    def commit_changes(self, args: argparse.Namespace, code: str) -> None:
         self.require_git_email_name(args.root)
         authors = set()  # type: Set[str]
         diffs = u"{}".format(git('--no-pager', '-C', args.root, 'diff', '--name-only', '--cached'))
@@ -321,18 +342,18 @@ def upstream_commit(self, args: argparse.Namespace, code: str) -> None:
             previous_message = u"{}".format(git(
                 '--no-pager', '-C', args.root, 'log', '-n', '1', path,
                 _encoding='utf-8'))
-            update_re = re.compile(r'(?:updated from|  revision:) (\w+)')
-            m = update_re.search(previous_message)
+            m = self.updated_commit_re.search(previous_message)
             if m:
                 origin = m.group(1)
             else:
                 origin = ''
-            authors |= self.translators(args, path, '{}..i18n/i18n'.format(origin))
+            since = self.get_commit_timestamp(origin)
+            authors |= self.translators(args, path, since)
 
         authors_as_str = u"\n  ".join(sorted(authors))
 
-        current = git('-C', args.root, 'rev-parse', 'i18n/i18n')
-        info = I18NTool.SUPPORTED_LANGUAGES[code]
+        current = git('-C', args.root, 'rev-parse', args.target)
+        info = self.supported_languages[code]
         message = textwrap.dedent(u"""
         l10n: updated {name} ({code})
 
@@ -341,7 +362,7 @@ def upstream_commit(self, args: argparse.Namespace, code: str) -> None:
 
         updated from:
           repo: {remote}
-          revision: {current}
+          commit: {current}
         """).format(
             remote=args.url,
             name=info['name'],
@@ -366,6 +387,14 @@ def set_update_from_weblate_parser(self, subps: _SubParsersAction) -> None:
             default=url,
             help=('URL of the weblate repository'
                   ' (default {})'.format(url)))
+        parser.add_argument(
+            '--target',
+            default="i18n/i18n",
+            help=(
+                'Commit on i18n branch at which to stop gathering translator contributions '
+                '(default: i18n/i18n)'
+            )
+        )
         parser.add_argument(
             '--supported-languages',
             help='comma separated list of supported languages')
@@ -387,12 +416,12 @@ def set_list_locales_parser(self, subps: _SubParsersAction) -> None:
 
     def list_locales(self, args: argparse.Namespace) -> None:
         if args.lines:
-            for l in sorted(list(self.SUPPORTED_LANGUAGES.keys()) + ['en_US']):
+            for l in sorted(list(self.supported_languages.keys()) + ['en_US']):
                 print(l)
         elif args.python:
-            print(sorted(list(self.SUPPORTED_LANGUAGES.keys()) + ['en_US']))
+            print(sorted(list(self.supported_languages.keys()) + ['en_US']))
         else:
-            print(" ".join(sorted(list(self.SUPPORTED_LANGUAGES.keys()) + ['en_US'])))
+            print(" ".join(sorted(list(self.supported_languages.keys()) + ['en_US'])))
 
     def set_list_translators_parser(self, subps: _SubParsersAction) -> None:
         parser = subps.add_parser('list-translators',
@@ -409,50 +438,84 @@ def set_list_translators_parser(self, subps: _SubParsersAction) -> None:
             default=url,
             help=('URL of the weblate repository'
                   ' (default {})'.format(url)))
+        parser.add_argument(
+            '--target',
+            default="i18n/i18n",
+            help=(
+                'Commit on i18n branch at which to stop gathering translator contributions '
+                '(default: i18n/i18n)'
+            )
+        )
+        last_release = self.get_last_release()
+        parser.add_argument(
+            '--since',
+            default=last_release,
+            help=(
+                'Gather translator contributions from the time of this commit '
+                '(default: {})'.format(last_release)
+            )
+        )
         parser.add_argument(
             '--all',
             action="store_true",
             help=(
                 "List everyone who's ever contributed, instead of just since the last "
-                "sync from Weblate."
+                "release or specified commit."
             )
         )
         parser.set_defaults(func=self.list_translators)
 
-    def get_last_sync(self) -> Optional[str]:
-        commits = git('--no-pager', 'log', '--format=%h:%s', 'i18n/i18n', _encoding='utf-8')
-        for commit in commits:
-            commit_hash, msg = commit.split(':', 1)
-            if msg.startswith("l10n: sync "):
-                return commit_hash
-        return None
+    def get_last_release(self) -> Optional[str]:
+        """
+        Returns the last release tag, e.g. 1.5.0.
+        """
+        tags = subprocess.check_output(["git", "tag"]).decode("utf-8").splitlines()
+        release_tags = sorted([t.strip() for t in tags if self.release_tag_re.match(t)])
+        if not release_tags:
+            raise ValueError("Could not find a release tag!")
+        return release_tags[-1]
+
+    def get_commit_timestamp(self, commit):
+        timestamp = subprocess.check_output(
+            ["git", "log", "-n", "1", '--pretty=format:%ct', commit]
+        )
+        return timestamp.decode("utf-8").strip()
 
     def list_translators(self, args: argparse.Namespace) -> None:
         self.ensure_i18n_remote(args)
         app_template = "securedrop/translations/{}/LC_MESSAGES/messages.po"
         desktop_template = "install_files/ansible-base/roles/tails-config/templates/{}.po"
-        last_sync = self.get_last_sync()
-        for code, info in sorted(I18NTool.SUPPORTED_LANGUAGES.items()):
+        since = self.get_commit_timestamp(args.since) if not args.all else None
+        if args.all:
+            print("Listing all translators who have ever helped")
+        else:
+            print("Listing translators who have helped since {}".format(args.since))
+        for code, info in sorted(self.supported_languages.items()):
             translators = set([])
             paths = [
                 app_template.format(code),
                 desktop_template.format(info["desktop"]),
             ]
             for path in paths:
                 try:
-                    commit_range = "i18n/i18n"
-                    if last_sync and not args.all:
-                        commit_range = '{}..{}'.format(last_sync, commit_range)
-                    t = self.translators(args, path, commit_range)
+                    t = self.translators(args, path, since)
                     translators.update(t)
                 except Exception as e:
                     print("Could not check git history of {}: {}".format(path, e), file=sys.stderr)
-            print(u"{} ({}):\n  {}".format(code, info["name"], "\n  ".join(sorted(translators))))
+            print(
+                "{} ({}):{}".format(
+                    code, info["name"],
+                    "\n  {}\n".format(
+                        "\n  ".join(sorted(translators))) if translators else "\n"
+                )
+            )
 
     def get_args(self) -> argparse.ArgumentParser:
         parser = argparse.ArgumentParser(
             prog=__file__,
             description='i18n tool for SecureDrop.')
+        parser.set_defaults(func=lambda args: parser.print_help())
+
         parser.add_argument('-v', '--verbose', action='store_true')
         subps = parser.add_subparsers()