rhai/tests/var_scope.rs
2021-05-22 19:14:24 +08:00

123 lines
3.5 KiB
Rust

use rhai::{Engine, EvalAltResult, Position, Scope, INT};
#[test]
fn test_var_scope() -> Result<(), Box<EvalAltResult>> {
let engine = Engine::new();
let mut scope = Scope::new();
engine.eval_with_scope::<()>(&mut scope, "let x = 4 + 5")?;
assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "x")?, 9);
engine.eval_with_scope::<()>(&mut scope, "x += 1; x += 2;")?;
assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "x")?, 12);
scope.set_value("x", 42 as INT);
assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "x")?, 42);
engine.eval_with_scope::<()>(&mut scope, "{let x = 3}")?;
assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "x")?, 42);
Ok(())
}
#[test]
fn test_var_is_def() -> Result<(), Box<EvalAltResult>> {
let engine = Engine::new();
assert!(engine.eval::<bool>(
r#"
let x = 42;
is_def_var("x")
"#
)?);
assert!(!engine.eval::<bool>(
r#"
let x = 42;
is_def_var("y")
"#
)?);
assert!(engine.eval::<bool>(
r#"
const x = 42;
is_def_var("x")
"#
)?);
Ok(())
}
#[test]
fn test_scope_eval() -> Result<(), Box<EvalAltResult>> {
let engine = Engine::new();
// First create the state
let mut scope = Scope::new();
// Then push some initialized variables into the state
// NOTE: Remember the default numbers used by Rhai are INT and f64.
// Better stick to them or it gets hard to work with other variables in the script.
scope.push("y", 42 as INT);
scope.push("z", 999 as INT);
// First invocation
engine
.eval_with_scope::<()>(&mut scope, " let x = 4 + 5 - y + z; y = 1;")
.expect("variables y and z should exist");
// Second invocation using the same state
let result = engine.eval_with_scope::<INT>(&mut scope, "x")?;
println!("result: {}", result); // should print 966
// Variable y is changed in the script
assert_eq!(
scope
.get_value::<INT>("y")
.expect("variable y should exist"),
1
);
Ok(())
}
#[test]
fn test_var_resolver() -> Result<(), Box<EvalAltResult>> {
let mut engine = Engine::new();
let mut scope = Scope::new();
scope.push("innocent", 1 as INT);
scope.push("chameleon", 123 as INT);
scope.push("DO_NOT_USE", 999 as INT);
engine.on_var(|name, _, context| {
match name {
"MYSTIC_NUMBER" => Ok(Some((42 as INT).into())),
// Override a variable - make it not found even if it exists!
"DO_NOT_USE" => {
Err(EvalAltResult::ErrorVariableNotFound(name.to_string(), Position::NONE).into())
}
// Silently maps 'chameleon' into 'innocent'.
"chameleon" => context
.scope()
.get_value("innocent")
.map(Some)
.ok_or_else(|| {
EvalAltResult::ErrorVariableNotFound(name.to_string(), Position::NONE).into()
}),
// Return Ok(None) to continue with the normal variable resolution process.
_ => Ok(None),
}
});
assert_eq!(
engine.eval_with_scope::<INT>(&mut scope, "MYSTIC_NUMBER")?,
42
);
assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "chameleon")?, 1);
assert!(
matches!(*engine.eval_with_scope::<INT>(&mut scope, "DO_NOT_USE").expect_err("should error"),
EvalAltResult::ErrorVariableNotFound(n, _) if n == "DO_NOT_USE")
);
Ok(())
}