(module
  ;; import the browser console object, you'll need to pass this in from JavaScript
  (import "console" "log" (func $log (param i32)))

  (func
    i32.const 0 ;; change to positive number if you want to run the if block
    if
      i32.const 1
      call $log ;; should log '1'
    end
  )

  (start 1) ;; run the first function automatically
)
var url = "{%wasm-url%}";
await WebAssembly.instantiateStreaming(fetch(url), {console});

Wat Demo: end