import * as assert from '../assert.js'

import Builder from '../Builder.js'

const b = new Builder();

b.Type().End()

.Import().End()

.Function().End()

.Export()

.Function("fac")

.End()

.Code()

.Function("fac", { params: ["i32"], ret: "i32" })

.GetLocal(0)

.I32Const(0)

.I32Eq()

.If("void", b =>

b.I32Const(1)

.Return()

)

.GetLocal(0)

.GetLocal(0)

.I32Const(1)

.I32Sub()

.Call(0)

.I32Mul()

.Return()

.End()

.End()

const m = new WebAssembly.Module(b.WebAssembly().get());

const fac = (new WebAssembly.Instance(m)).exports.fac;

assert.eq(fac(0), 1);

assert.eq(fac(1), 1);

assert.eq(fac(2), 2);

assert.eq(fac(4), 24);

assert.throws(() => fac(1e7), RangeError, "Maximum call stack size exceeded.");