Remove the saved Sublime Text session before each Docker run (#309)

Sublime Text is killed after the tests, so the cache volume keeps the
session that it last saved, with the views that tests had open at that
time. The next run restored those views before the tests started, which
made tests that expect no open views fail locally, while they passed on
CI, where every run starts without a session.

Author: rchl

docker/README.md

@@ -58,7 +58,9 @@ ut-run-tests . --file Example.sublime-syntax
 
 The container entrypoint writes a marker in `/root/.cache/unittesting`.
 With `-v unittesting-home:/root`, bootstrap/install runs once and later runs
-only refresh your package files and execute tests.
+only refresh your package files and execute tests. Each run removes the
+session that Sublime Text saved in the previous run, so that no views from
+earlier runs are open when the tests start.
 
 ## Concurrent runs and races
 

docker/entrypoint.sh

@@ -115,6 +115,14 @@ ensure_sublime_text_arch_matches() {
     fi
 }
 
+clear_saved_session() {
+    # Sublime Text is killed after the tests, so the cache volume keeps the
+    # session that it last saved, with the views that tests had open then.
+    # Start without it, like a CI runner does, so that Sublime Text doesn't
+    # restore those views.
+    rm -f "${ST_PACKAGES_DIR%/*}/Local/"*.sublime_session
+}
+
 ensure_sublime_text_arch_matches
 sudo sh -e /etc/init.d/xvfb start
 ensure_git_identity
@@ -127,6 +135,7 @@ if [ "$SUBLIME_TEXT_VERSION" -ge 4 ]; then
 else
     ST_PACKAGES_DIR="$HOME/.config/sublime-text-$SUBLIME_TEXT_VERSION/Packages"
 fi
+clear_saved_session
 
 if [ -d "$UNITTESTING_SOURCE/sbin" ]; then
     # Ensure UnitTesting comes from the local checkout running this script,