Function test_roundtrip

tests/all/component_model/strings.rs:101–193

(engine: &Engine, src: &str, dst: &str)

}

fn test_roundtrip(engine: &Engine, src: &str, dst: &str) -> Result<()> {
    println!("src={src} dst={dst}");

    let mk_echo = |name: &str, encoding: &str| {
        format!(
            r#"
(component {name}
    (import "echo" (func $echo (param "a" string) (result string)))
    (core instance $libc (instantiate $libc))
    (core func $echo (canon lower (func $echo)
        (memory $libc "memory")
        (realloc (func $libc "realloc"))
        string-encoding={encoding}
    ))
    (core instance $echo (instantiate $echo
        (with "libc" (instance $libc))
        (with "" (instance (export "echo" (func $echo))))
    ))
    (func (export "echo2") (param "a" string) (result string)
        (canon lift
            (core func $echo "echo")
            (memory $libc "memory")
            (realloc (func $libc "realloc"))
            string-encoding={encoding}
        )
    )
)
            "#
        )
    };

    let src = mk_echo("$src", src);
    let dst = mk_echo("$dst", dst);
    let component = format!(
        r#"
(component
    (import "host" (func $host (param "a" string) (result string)))

    (core module $libc
        (memory (export "memory") 1)
        {REALLOC_AND_FREE}
    )
    (core module $echo
        (import "" "echo" (func $echo (param i32 i32 i32)))
        (import "libc" "memory" (memory 0))
        (import "libc" "realloc" (func $realloc (param i32 i32 i32 i32) (result i32)))

        (func (export "echo") (param i32 i32) (result i32)
            (local $retptr i32)
            (local.set $retptr
                (call $realloc
                    (i32.const 0)
                    (i32.const 0)
                    (i32.const 4)
                    (i32.const 8)))
            (call $echo
                (local.get 0)
                (local.get 1)