Live runtime verification

Rust tests in this browser

Cargo compiled the same dependency-free Rust test inventory—the same seven #[test] functions used by the native CI lane, including Behavioral coverage—into wasm32-unknown-unknown. A separate host adapter checks passive page output and WebAssembly delivery.

Rust · WebAssembly

Running…

Checking the page, loading WebAssembly, and running the Cargo-generated Rust test harness.

0/?

Passed0

Failed0

Skipped0

Checks running in this page

Waiting for the browser test adapter

Host checks plus one real Rust inventory.

The named heading, target, and delivery rows are browser-host checks, not Rust tests. The final aggregate row calls the real Cargo-generated harness once; native Cargo and WASM execute the exact same seven Rust functions. Harness result: not run.

Exact boundary

What this browser path can test

Layer	Supported	Not supported
Rust WASM	Target-compatible Rust logic in the same library `#[test]` functions; safe aggregate `main()` status.	JavaScript functions, DOM or console APIs, individual browser diagnostics, and OS- or thread-dependent tests.
Host adapter	One snapshot of connected, visible, nonempty rendered text with optional exact matching; fetch, MIME, instantiation, export, and status checks.	Clicks, typing, focus, navigation, arbitrary properties, custom network assertions, waits, or retries.

Rust does not call the page.

This repository's module has zero host imports, and the browser supplies no import object. Test JavaScript functions directly in the JavaScript lane; this adapter can only observe text they rendered before browser.js started. See the complete browser contract.

Copy-ready example

A basic Rust suite

Put this in your crate's src/lib.rs. Native Cargo prints individual Rust test names and assertion diagnostics; cargo vanilla-test --browser compiles the same #[test] inventory into the deployable runner above.

#[cfg(test)]
mod tests {
    use vanilla_test::VanillaTest;

    #[test]
    fn basic_suite() {
        let mut test = VanillaTest::new();

        test.expects("2 + 2 equals 4").unwrap();
        if 2 + 2 == 4 {
            test.pass().unwrap();
        } else {
            test.fail().unwrap();
        }
        test.done().unwrap();

        test.expects("uppercase preserves the word").unwrap();
        if "rust".to_uppercase() == "RUST" {
            test.pass().unwrap();
        } else {
            test.fail().unwrap();
        }
        test.done().unwrap();

        let result = test.report().unwrap();
        assert!(result.ok, "{}", result.report);
        assert_eq!(result.total, 2);
    }
}

cargo test
cargo vanilla-test --browser

Why aggregate status?

Bare wasm32-unknown-unknown has no stdout host. The browser shows the host checks and the real Rust harness status; native Cargo prints each Rust test name and assertion diagnostic.

No wasm-bindgen, unsafe export, JavaScript copy of the Rust assertions, generated glue, or wrapper crate is involved.

Read the browser checks Read the Rust documentation