# Description
Adds support for running plugins using local socket communication
instead of stdio. This will be an optional thing that not all plugins
have to support.
This frees up stdio for use to make plugins that use stdio to create
terminal UIs, cc @amtoine, @fdncred.
This uses the [`interprocess`](https://crates.io/crates/interprocess)
crate (298 stars, MIT license, actively maintained), which seems to be
the best option for cross-platform local socket support in Rust. On
Windows, a local socket name is provided. On Unixes, it's a path. The
socket name is kept to a relatively small size because some operating
systems have pretty strict limits on the whole path (~100 chars), so on
macOS for example we prefer `/tmp/nu.{pid}.{hash64}.sock` where the hash
includes the plugin filename and timestamp to be unique enough.
This also adds an API for moving plugins in and out of the foreground
group, which is relevant for Unixes where direct terminal control
depends on that.
TODO:
- [x] Generate local socket path according to OS conventions
- [x] Add support for passing `--local-socket` to the plugin executable
instead of `--stdio`, and communicating over that instead
- [x] Test plugins that were broken, including
[amtoine/nu_plugin_explore](https://github.com/amtoine/nu_plugin_explore)
- [x] Automatically upgrade to using local sockets when supported,
falling back if it doesn't work, transparently to the user without any
visible error messages
- Added protocol feature: `LocalSocket`
- [x] Reset preferred mode to `None` on `register`
- [x] Allow plugins to detect whether they're running on a local socket
and can use stdio freely, so that TUI plugins can just produce an error
message otherwise
- Implemented via `EngineInterface::is_using_stdio()`
- [x] Clean up foreground state when plugin command exits on the engine
side too, not just whole plugin
- [x] Make sure tests for failure cases work as intended
- `nu_plugin_stress_internals` added
# User-Facing Changes
- TUI plugins work
- Non-Rust plugins could optionally choose to use this
- This might behave differently, so will need to test it carefully
across different operating systems
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] Document local socket option in plugin contrib docs
- [ ] Document how to do a terminal UI plugin in plugin contrib docs
- [ ] Document: `EnterForeground` engine call
- [ ] Document: `LeaveForeground` engine call
- [ ] Document: `LocalSocket` protocol feature
# Description
Adds a `nu-plugin-test-support` crate with an interface that supports
testing plugins.
Unlike in reality, these plugins run in the same process on separate
threads. This will allow
testing aspects of the plugin internal state and handling serialized
plugin custom values easily.
We still serialize their custom values and all of the engine to plugin
logic is still in play, so
from a logical perspective this should still expose any bugs that would
have been caused by that.
The only difference is that it doesn't run in a different process, and
doesn't try to serialize
everything to the final wire format for stdin/stdout.
TODO still:
- [x] Clean up warnings about private types exposed in trait definition
- [x] Automatically deserialize plugin custom values in the result so
they can be inspected
- [x] Automatic plugin examples test function
- [x] Write a bit more documentation
- [x] More tests
- [x] Add MIT License file to new crate
# User-Facing Changes
Plugin developers get a nice way to test their plugins.
# Tests + Formatting
Run the tests with `cargo test -p nu-plugin-test-support --
--show-output` to see some examples of what the failing test output for
examples can look like. I used the `difference` crate (MIT licensed) to
make it look nice.
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] Add a section to the book about testing
- [ ] Test some of the example plugins this way
- [ ] Add example tests to nu_plugin_template so plugin developers have
something to start with
