b90c99b87c
As a pure javascript project, building is really just a glorified copy operation, so success doesn't even indicate that sources are syntactically correct (a.k.a. "compile-tested"). We can at least get some minimal testing by performing some basic syntax checking when SpilderMonkey's JS shell is available. Fixes https://gitlab.gnome.org/GNOME/gnome-shell-extensions/issues/32