nop

nop stands for no-operation. It literally does nothing.

Try it

(module
  (func (export "do_nothing")
    nop
  )
)

const url = "{%wasm-url%}";
await WebAssembly.instantiateStreaming(fetch(url)).then((result) => {
  result.instance.exports.do_nothing();
});

wasm

nop

Instruction	Binary opcode
`nop`	`0x01`