This commit adds `--unstable-hmr` flag, that enabled Hot Module Replacement.
This flag works like `--watch` and accepts the same arguments. If
HMR is not possible the process will be restarted instead.
Currently HMR is only supported in `deno run` subcommand.
Upon HMR a `CustomEvent("hmr")` will be dispatched that contains
information which file was changed in its `details` property.
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Co-authored-by: Valentin Anger <syrupthinker@gryphno.de>
Co-authored-by: David Sherret <dsherret@gmail.com>
This commit introduces "WatcherCommunicator" struct that
is used facilitate bi-directional communication between CLI
file watcher and the watched function.
Prerequisite for https://github.com/denoland/deno/pull/20876
Fixes #16699 and #18960 by ensuring that we release our HTTP
`spawn_local` tasks when the HTTP resource is dropped.
Because our cancel handle was being projected from the resource via
`RcMap`, the resource was never `Drop`ped. By splitting the handle out
into its own `Rc`, we can avoid keeping the resource alive and let it
drop to cancel everything.
This commit changes "ProcState" to store "file_fetcher" field in an "Arc",
allowing it to be preserved between restarts and thus keeping the state
alive between the restarts. File watchers for "deno test" and "deno bench"
now reset "ProcState" between restarts.
