Multi-page static site: home, about, and a dynamic greeting route

soma.toml

[package]
name = "web-corpus"
version = "0.1.0"
entry = "todo_state.cell"

[verify]
cells = ["TodoService"]
deadlock_free = true
eventually = ["Done", "Cancelled"]

site_router.cell

// Multi-page static site: home, about, and a dynamic greeting route.
// Demonstrates html() pages, path captures, and a 404 fallthrough.

cell Site {
    face {
        signal request(method: String, path: String, body: String) -> String
        signal greet(name: String) -> String
        promise "static pages plus one dynamic route"
    }

    on _page(title: String, body: String) {
        return concat(
            concat("<!DOCTYPE html><html><head><title>", title),
            concat("</title></head><body><nav><a href='/'>home</a> | <a href='/about'>about</a></nav>",
                   concat(body, "</body></html>")))
    }

    on greet(name: String) {
        let safe = escape_html(name)
        return _page("Hello", "<h1>Hello, {safe}!</h1>")
    }

    on request(method: String, path: String, body: String) {
        let req = map("method", method, "path", path)
        match req {
            {method: "GET", path: "/"}             -> html(_page("Home", "<h1>Welcome</h1><p>A site in Soma.</p>"))
            {method: "GET", path: "/about"}        -> html(_page("About", "<h1>About</h1><p>Built with cells.</p>"))
            {method: "GET", path: "/hello/" + nm}  -> html(greet(nm))
            _                                      -> html(404, _page("Not Found", "<h1>404</h1>"))
        }
    }
}

cell test SiteTest {
    rules {
        assert contains(greet("Ada"), "Hello, Ada!")
        assert contains(greet("<x>"), "&lt;x&gt;")
        assert contains(_page("T", "B"), "<title>T</title>")
        assert contains(_page("T", "B"), "<a href='/about'>about</a>")
    }
}