nushell/crates/nu-plugin-test-support/src/spawn_fake_plugin.rs
Devyn Cairns 0c4d5330ee
Split the plugin crate (#12563)
# Description

This breaks `nu-plugin` up into four crates:

- `nu-plugin-protocol`: just the type definitions for the protocol, no
I/O. If someone wanted to wire up something more bare metal, maybe for
async I/O, they could use this.
- `nu-plugin-core`: the shared stuff between engine/plugin. Less stable
interface.
- `nu-plugin-engine`: everything required for the engine to talk to
plugins. Less stable interface.
- `nu-plugin`: everything required for the plugin to talk to the engine,
what plugin developers use. Should be the most stable interface.

No changes are made to the interface exposed by `nu-plugin` - it should
all still be there. Re-exports from `nu-plugin-protocol` or
`nu-plugin-core` are used as required. Plugins shouldn't ever have to
use those crates directly.

This should be somewhat faster to compile as `nu-plugin-engine` and
`nu-plugin` can compile in parallel, and the engine doesn't need
`nu-plugin` and plugins don't need `nu-plugin-engine` (except for test
support), so that should reduce what needs to be compiled too.

The only significant change here other than splitting stuff up was to
break the `source` out of `PluginCustomValue` and create a new
`PluginCustomValueWithSource` type that contains that instead. One bonus
of that is we get rid of the option and it's now more type-safe, but it
also means that the logic for that stuff (actually running the plugin
for custom value ops) can live entirely within the `nu-plugin-engine`
crate.

# User-Facing Changes
- New crates.
- Added `local-socket` feature for `nu` to try to make it possible to
compile without that support if needed.

# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
2024-04-27 12:08:12 -05:00

80 lines
2.6 KiB
Rust

use std::sync::{mpsc, Arc};
use nu_plugin::Plugin;
use nu_plugin_core::{InterfaceManager, PluginRead, PluginWrite};
use nu_plugin_engine::{PluginInterfaceManager, PluginSource};
use nu_plugin_protocol::{PluginInput, PluginOutput};
use nu_protocol::{PluginIdentity, ShellError};
use crate::fake_persistent_plugin::FakePersistentPlugin;
struct FakePluginRead<T>(mpsc::Receiver<T>);
struct FakePluginWrite<T>(mpsc::Sender<T>);
impl<T> PluginRead<T> for FakePluginRead<T> {
fn read(&mut self) -> Result<Option<T>, ShellError> {
Ok(self.0.recv().ok())
}
}
impl<T: Clone + Send> PluginWrite<T> for FakePluginWrite<T> {
fn write(&self, data: &T) -> Result<(), ShellError> {
self.0
.send(data.clone())
.map_err(|err| ShellError::IOError {
msg: err.to_string(),
})
}
fn flush(&self) -> Result<(), ShellError> {
Ok(())
}
}
fn fake_plugin_channel<T: Clone + Send>() -> (FakePluginRead<T>, FakePluginWrite<T>) {
let (tx, rx) = mpsc::channel();
(FakePluginRead(rx), FakePluginWrite(tx))
}
/// Spawn a plugin on another thread and return the registration
pub(crate) fn spawn_fake_plugin(
name: &str,
plugin: Arc<impl Plugin + Send + 'static>,
) -> Result<Arc<FakePersistentPlugin>, ShellError> {
let (input_read, input_write) = fake_plugin_channel::<PluginInput>();
let (output_read, output_write) = fake_plugin_channel::<PluginOutput>();
let identity = PluginIdentity::new_fake(name);
let reg_plugin = Arc::new(FakePersistentPlugin::new(identity.clone()));
let source = Arc::new(PluginSource::new(reg_plugin.clone()));
// The fake plugin has no process ID, and we also don't set the garbage collector
let mut manager = PluginInterfaceManager::new(source, None, input_write);
// Set up the persistent plugin with the interface before continuing
let interface = manager.get_interface();
interface.hello()?;
reg_plugin.initialize(interface);
// Start the interface reader on another thread
std::thread::Builder::new()
.name(format!("fake plugin interface reader ({name})"))
.spawn(move || manager.consume_all(output_read).expect("Plugin read error"))?;
// Start the plugin on another thread
let name_string = name.to_owned();
std::thread::Builder::new()
.name(format!("fake plugin runner ({name})"))
.spawn(move || {
nu_plugin::serve_plugin_io(
&*plugin,
&name_string,
move || input_read,
move || output_write,
)
.expect("Plugin runner error")
})?;
Ok(reg_plugin)
}