add shutdown logging, publish checklist (#184)

* add shutdown logging, publish checklist

* testpypi publish

README.md

@@ -129,25 +129,30 @@ To debug `git webdiff`, run:
 
     ./test-gitwebdiff.sh
 
+## Publishing
+
 To iterate on the PyPI package, run:
 
-    # from outside the webdiff virtualenv:
     pip3 uninstall webdiff
-
-    # from inside the webdiff virtualenv, adjust for current version
     poetry build
     pip3 install dist/webdiff-?.?.?.tar.gz
 
 To publish to pypitest:
 
     poetry build
-    ???
+    poetry publish -r testpypi
 
 And to the real pypi:
 
     poetry publish
 
-See [pypirc][] docs for details on setting up `~/.pypirc`.
+See [pypirc][] and [poetry][] docs for details on setting up tokens for pypi.
+
+Publication checklist. Do these from _outside_ the webdiff directory:
+
+- Run `webdiff webdiff/testdata/.../{left,right}`
+- Run `git webdiff 52aa15f^..52aa15f` in the codediff.js repo
+- Run `webdiff https://github.com/danvk/webdiff/pull/160`
 
 ## Implementation notes
 
@@ -176,3 +181,4 @@ There's one complication involving symlinks. `git difftool -d` may fill one of t
 [ImageMagick]: https://imagemagick.org/index.php
 [git config]: https://git-scm.com/docs/git-config
 [themes]: http://example.com
+[poetry]: https://python-poetry.org/docs/repositories/#publishable-repositories

webdiff/app.py

@@ -225,6 +225,7 @@ def shutdown():
             if LAST_REQUEST_MS <= last_ms:  # subsequent requests abort shutdown
                 # See https://stackoverflow.com/a/19040484/388951
                 # and https://stackoverflow.com/q/4330111/388951
+                sys.stderr.write('Shutting down...\n')
                 threading.Thread(target=self.server.shutdown, daemon=True).start()
             else:
                 logging.debug('Received subsequent request; canceling shutdown')