1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
use crate::convert::{Error, FromMrb, TryFromMrb};
use crate::value::types::{Ruby, Rust};
use crate::value::Value;
use crate::Mrb;

impl FromMrb<String> for Value {
    type From = Rust;
    type To = Ruby;

    fn from_mrb(interp: &Mrb, value: String) -> Self {
        // mruby `String` is just bytes, so get a pointer to the underlying
        // `&[u8]` infallibly and convert that to a `Value`.
        Self::from_mrb(interp, value.as_bytes())
    }
}

impl FromMrb<&str> for Value {
    type From = Rust;
    type To = Ruby;

    fn from_mrb(interp: &Mrb, value: &str) -> Self {
        // mruby `String` is just bytes, so get a pointer to the underlying
        // `&[u8]` infallibly and convert that to a `Value`.
        Self::from_mrb(interp, value.as_bytes())
    }
}

impl TryFromMrb<Value> for String {
    type From = Ruby;
    type To = Rust;

    unsafe fn try_from_mrb(
        interp: &Mrb,
        value: Value,
    ) -> Result<Self, Error<Self::From, Self::To>> {
        if value.ruby_type() == Ruby::Symbol {
            return Ok(value.to_s());
        }
        // `Vec<u8>` converter operates on `Ruby::String`
        let bytes = <Vec<u8>>::try_from_mrb(interp, value).map_err(|err| Error {
            from: err.from,
            to: Rust::String,
        })?;
        // This converter requires that the bytes be valid UTF-8 data. If the
        // `mrb_value` is binary data, use the `Vec<u8>` converter.
        Self::from_utf8(bytes).map_err(|_| Error {
            from: Ruby::String,
            to: Rust::String,
        })
    }
}

#[cfg(test)]
// FromMrb<String> is implemented in terms of FromMrb<&str> so only implement
// the tests for String to exercise both code paths.
mod tests {
    use quickcheck_macros::quickcheck;
    use std::convert::TryInto;

    use crate::convert::{Error, FromMrb, TryFromMrb};
    use crate::eval::MrbEval;
    use crate::sys;
    use crate::value::types::{Ruby, Rust};
    use crate::value::Value;

    #[test]
    fn fail_convert() {
        let interp = crate::interpreter().expect("mrb init");
        // get a mrb_value that can't be converted to a primitive type.
        let value = interp.eval("Object.new").expect("eval");
        let expected = Error {
            from: Ruby::Object,
            to: Rust::String,
        };
        let result = unsafe { String::try_from_mrb(&interp, value) }.map(|_| ());
        assert_eq!(result, Err(expected));
    }

    #[allow(clippy::needless_pass_by_value)]
    #[quickcheck]
    fn convert_to_string(s: String) -> bool {
        let interp = crate::interpreter().expect("mrb init");
        let value = Value::from_mrb(&interp, s.clone());
        let ptr = unsafe { sys::mrb_string_value_ptr(interp.borrow().mrb, value.inner()) };
        let len = unsafe { sys::mrb_string_value_len(interp.borrow().mrb, value.inner()) };
        let string =
            unsafe { std::slice::from_raw_parts(ptr as *const u8, len.try_into().unwrap()) };
        s.as_bytes() == string
    }

    #[allow(clippy::needless_pass_by_value)]
    #[quickcheck]
    fn string_with_value(s: String) -> bool {
        let interp = crate::interpreter().expect("mrb init");
        let value = Value::from_mrb(&interp, s.clone());
        value.to_s() == s
    }

    #[allow(clippy::needless_pass_by_value)]
    #[quickcheck]
    fn roundtrip(s: String) -> bool {
        let interp = crate::interpreter().expect("mrb init");
        let value = Value::from_mrb(&interp, s.clone());
        let value = unsafe { String::try_from_mrb(&interp, value) }.expect("convert");
        value == s
    }

    #[quickcheck]
    fn roundtrip_err(b: bool) -> bool {
        let interp = crate::interpreter().expect("mrb init");
        let value = Value::from_mrb(&interp, b);
        let value = unsafe { String::try_from_mrb(&interp, value) };
        let expected = Err(Error {
            from: Ruby::Bool,
            to: Rust::String,
        });
        value == expected
    }

    #[test]
    fn symbol_to_string() {
        let interp = crate::interpreter().expect("mrb init");
        let value = interp.eval(":sym").expect("eval");
        let value = unsafe { String::try_from_mrb(&interp, value) }.expect("convert");
        assert_eq!(&value, "sym");
    }
}