rhai/tests/side_effects.rs

100 lines
2.5 KiB
Rust

///! This test simulates an external command object that is driven by a script.
use rhai::{Engine, EvalAltResult, RegisterFn, Scope, INT};
use std::sync::{Arc, Mutex};
/// External command.
struct Command {
state: i64,
}
impl Command {
/// Do some action.
pub fn action(&mut self, val: i64) {
self.state = val;
}
/// Get current value.
pub fn get(&self) -> i64 {
self.state
}
}
/// Wrapper object to wrap a command object.
#[derive(Clone)]
struct CommandWrapper {
command: Arc<Mutex<Command>>,
}
impl CommandWrapper {
/// Delegate command action.
pub fn do_action(&mut self, x: i64) {
let mut command = self.command.lock().unwrap();
let val = command.get();
command.action(val + x);
}
/// Delegate get value action.
pub fn get_value(&mut self) -> i64 {
let command = self.command.lock().unwrap();
command.get()
}
}
#[cfg(not(feature = "no_object"))]
#[test]
fn test_side_effects_command() -> Result<(), EvalAltResult> {
let mut engine = Engine::new();
let mut scope = Scope::new();
// Create the command object with initial state, handled by an `Rc`.
let command = Arc::new(Mutex::new(Command { state: 12 }));
assert_eq!(command.lock().unwrap().get(), 12);
// Create the wrapper.
let wrapper = CommandWrapper {
command: command.clone(), // Notice this clones the `Rc` only
};
// Make the wrapper a singleton in the script environment.
scope.push_constant("Command", wrapper);
// Register type.
engine.register_type_with_name::<CommandWrapper>("CommandType");
engine.register_fn("action", CommandWrapper::do_action);
engine.register_get("value", CommandWrapper::get_value);
assert_eq!(
engine.eval_with_scope::<INT>(
&mut scope,
r"
// Drive the command object via the wrapper
Command.action(30);
Command.value
"
)?,
42
);
// Make sure the actions are properly performed
assert_eq!(command.lock().unwrap().get(), 42);
Ok(())
}
#[test]
fn test_side_effects_print() -> Result<(), EvalAltResult> {
use std::sync::RwLock;
let result = RwLock::new(String::from(""));
{
let mut engine = Engine::new();
// Override action of 'print' function
engine.on_print(|s| result.write().unwrap().push_str(s));
engine.consume("print(40 + 2);")?;
}
assert_eq!(*result.read().unwrap(), "42");
Ok(())
}