Does wasm-bindgen search output artifacts based on $CARGO_TARGET_DIR ?

[huangjj27]

In the past week, I was trying to fix rustwasm/wasm-pack#390. Then, I write a test case as follow:

#[cfg(target_os = "windows")]
#[test]
fn it_format_out_dir_on_windows() {
    let fixture = utils::fixture::js_hello_world();
    fixture.install_local_wasm_bindgen();
    let cli = Cli::from_iter_safe(vec![
        "wasm-pack",
        "build",
        &fixture.path.display().to_string(),
    ])
    .unwrap();
    let logger = logger::new(&cli.cmd, 3).unwrap();
    let result =
        command::run_wasm_pack(cli.cmd, &logger).expect("js_hello_world example should pass");

    let wasm_pack_log = utils::file::read_file(&fixture.path.join("wasm-pack.log")).unwrap();
    assert!(
        wasm_pack_log.contains(r"Your wasm pkg is ready to publish at \\?\C:\Users\"),
        "directories in wasm-pack.log should be well formatted",
    );
}

the test generate a temp project directory c:\Users\34937\Documents\wasm-pack\target\t\.tmpfrYWhr\wasm-pack, let's call it the tmp_wasm_pack.
But, In the wasm-pack.log generated at the tmp_wasm_pack, it complains that a wasm file is not found:

error: failed to read `target/wasm32-unknown-unknown/release/js_hello_world.wasm`
	caused by: 系统找不到指定的路径。 (os error 3)      # system can't find the path

What I discover, is that in order to reuse artifacts, the $CARGO_TARGET_DIR of tmp_wasm_pack is set to the same target directory as wasm-pack's, declared at:

// tests/utils/fixture.rs line 28-48
impl Fixture {
    /// Create a new test fixture in a temporary directory.
    pub fn new() -> Fixture {
        // Make sure that all fixtures end up sharing a target dir, and we don't
        // recompile wasm-bindgen and friends many times over.
        static SET_TARGET_DIR: Once = ONCE_INIT;
        let target_dir = Path::new(env!("CARGO_MANIFEST_DIR")).join("target");
        SET_TARGET_DIR.call_once(|| {
            env::set_var("CARGO_TARGET_DIR", &target_dir);
        });

        let root = target_dir.join("t");
        fs::create_dir_all(&root).unwrap();
        let dir = TempDir::new_in(&root).unwrap();
        let path = dir.path().join("wasm-pack");
        eprintln!("Created fixture at {}", path.display());
        Fixture {
            dir: ManuallyDrop::new(dir),
            path,
        }
    }

    // omitting...
}

I believe it's the reset of $CARGO_TARGET_DIR that causes the problem when running wasm-bindgen in wasm-pack, and I wonder if wasm-bindgen searches output artifacts based on $CARGO_TARGET_DIR. If so, wasm-bindgen should find out these artifacts lay in `wasm-pack/target/wasm32-unknown-unknown

[alexcrichton]

Currently wasm-bindgen doesn't do any searching around, it only uses the path that's passed in. The wasm-bindgen-test-runner does do some inference based on the input path, but it also doesn't do any searching. I think this may be a bug in the test perhaps?

[huangjj27]

thanks， I will do more research to locate the reason.

[huangjj27]

I found that it is caused by rustwasm/wasm-pack#414. The issue is closing