Before the change, all code fragment sessions were invalidated on any
PSI change. It was a simple solution, though not very effective.
Fragments were invalidated not only on a physical module change, but
also on change in another, unrelated code fragment.
As code fragment sessions were reworked to support also ordinary '.kt'
files, the old logic started to have even less sense, because ordinary
dangling files do not have a context element (they only have a context
module).
Currently, code fragment sessions are invalidated on any change in a
physical (non-dangling) module, and are also invalidated on any change
in their contextual dangling module, if any. With some work, this can be
improved further, so code fragments will be invalidated only on changes
in modules they depend on.
Relevant tests can be found in the IntelliJ project
(DanglingFileModuleInvalidationTest).
Yan Zhulanow
7944602066