1// Copyright 2022 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5//go:build js
6
7package osinfo
8
9import (
10	"fmt"
11	"syscall/js"
12)
13
14// Version returns the OS version name/number.
15func Version() (string, error) {
16	// Version detection on Wasm varies depending on the underlying runtime
17	// (browser, node, etc), nor is there a standard via something like
18	// WASI (see https://go.dev/issue/31105). For now, attempt a few simple
19	// combinations for the convenience of reading logs at build.golang.org
20	// and local development. It's not a goal to recognize all environments.
21	if v, ok := node(); ok {
22		return "Node.js " + v, nil
23	}
24	return "", fmt.Errorf("unrecognized environment")
25}
26
27func node() (version string, ok bool) {
28	// Try the https://nodejs.org/api/process.html#processversion API.
29	p := js.Global().Get("process")
30	if p.IsUndefined() {
31		return "", false
32	}
33	v := p.Get("version")
34	if v.IsUndefined() {
35		return "", false
36	}
37	return v.String(), true
38}
39