chore: add ToBytes/FromBytes implementations for bool (#855)

Fixes https://github.com/extism/extism/issues/838

convert/src/from_bytes.rs

@@ -141,6 +141,16 @@ impl FromBytesOwned for u32 {
     }
 }
 
+impl FromBytesOwned for bool {
+    fn from_bytes_owned(data: &[u8]) -> Result<Self, Error> {
+        if let Some(x) = data.first() {
+            Ok(*x != 0)
+        } else {
+            Err(Error::msg("Expected one byte to read boolean value"))
+        }
+    }
+}
+
 impl FromBytesOwned for () {
     fn from_bytes_owned(_: &[u8]) -> Result<Self, Error> {
         Ok(())

convert/src/tests.rs

@@ -61,6 +61,17 @@ fn rountrip_option() {
     assert_eq!(y.unwrap().0, z.unwrap().0);
 }
 
+#[test]
+fn check_bool() {
+    // `None` case
+    let a = true.to_bytes().unwrap();
+    let b = false.to_bytes().unwrap();
+    assert_ne!(a, b);
+
+    assert_eq!(a, [1]);
+    assert_eq!(b, [0]);
+}
+
 #[cfg(all(feature = "raw", target_endian = "little"))]
 mod raw_tests {
     use crate::*;

convert/src/to_bytes.rs

@@ -144,6 +144,14 @@ impl ToBytes<'_> for u32 {
     }
 }
 
+impl ToBytes<'_> for bool {
+    type Bytes = [u8; 1];
+
+    fn to_bytes(&self) -> Result<Self::Bytes, Error> {
+        Ok([*self as u8])
+    }
+}
+
 impl<'a, T: ToBytes<'a>> ToBytes<'a> for &'a T {
     type Bytes = T::Bytes;