ref: e384a34196d16392ecd428b63d21a3868e8957b6
dir: /cmd/gojafs/domino/domino.go/
package domino
import (
"bytes"
"embed"
"errors"
"fmt"
"github.com/dop251/goja"
"github.com/dop251/goja/parser"
"github.com/dop251/goja_nodejs/console"
"github.com/dop251/goja_nodejs/eventloop"
"github.com/dop251/goja_nodejs/require"
"io/ioutil"
"github.com/psilva261/opossum/logger"
"net/http"
"os"
"os/exec"
"path/filepath"
"regexp"
"strconv"
"strings"
"syscall"
"time"
)
var timeout = 60*time.Second
//go:embed domino-lib/*js
var lib embed.FS
//go:embed domintf.js
var domIntfJs embed.FS
var domIntf string
func init() {
data, err := domIntfJs.ReadFile("domintf.js")
if err != nil {
panic(err.Error())
}
domIntf = string(data)
}
type Mutation struct {
time.Time
Type int
Sel string
}
type Domino struct {
loop *eventloop.EventLoop
html string
outputHtml string
domChange chan Mutation
query func(sel, prop string) (val string, err error)
xhrq func(req *http.Request) (resp *http.Response, err error)
}
func NewDomino(
html string,
xhr func(req *http.Request) (resp *http.Response, err error),
query func(sel, prop string) (val string, err error),
) (d *Domino) {
d = &Domino{
html: html,
xhrq: xhr,
domChange: make(chan Mutation, 100),
query: query,
}
return
}
func (d *Domino) Start() {
log.Printf("Start event loop")
d.loop = eventloop.NewEventLoop()
d.loop.Start()
log.Printf("event loop started")
}
func (d *Domino) Stop() {
d.loop.Stop()
}
func IntrospectError(err error, script string) {
prefix := "Line "
i := strings.Index(err.Error(), prefix)
if i > 0 {
i += len(prefix)
s := err.Error()[i:]
yxStart := strings.Split(s, " ")[0]
yx := strings.Split(yxStart, ":")
y, _ := strconv.Atoi(yx[0])
x, _ := strconv.Atoi(yx[1])
lines := strings.Split(script, "\n")
if y - 1 > len(lines) - 1 {
y = len(lines)
}
if wholeLine := lines[y-1]; len(wholeLine) > 100 {
from := x - 50
to := x + 50
if from < 0 {
from = 0
}
if to >= len(wholeLine) {
to = len(wholeLine) - 1
}
log.Printf("the line: %v", wholeLine[from:to])
} else {
if y > 0 && len(lines[y-1]) < 120 {
log.Printf("%v: %v", y-1, lines[y-1])
}
if y < len(lines) {
log.Printf("%v: %v", y, lines[y])
}
if y+1 < len(lines) && len(lines[y+1]) < 120 {
log.Printf("%v: %v", y+1, lines[y+1])
}
}
}
}
func printCode(code string, maxWidth int) {
if maxWidth > len(code) {
maxWidth = len(code)
}
log.Infof("js code: %v", code[:maxWidth])
}
func srcLoader(fn string) ([]byte, error) {
path := filepath.FromSlash(fn)
if !strings.Contains(path, "domino-lib/") || !strings.HasSuffix(path, ".js") {
return nil, require.ModuleFileDoesNotExistError
}
data, err := lib.ReadFile(path)
if err != nil {
if os.IsNotExist(err) || errors.Is(err, syscall.EISDIR) {
err = require.ModuleFileDoesNotExistError
} else {
log.Errorf("srcLoader: handling of require('%v') is not implemented", fn)
}
}
return data, err
}
func (d *Domino) Exec(script string, initial bool) (res string, err error) {
r := regexp.MustCompile(`^\s*<!--`)
rr := regexp.MustCompile(`-->\s*$`)
script = r.ReplaceAllString(script, "//")
script = rr.ReplaceAllString(script, "//")
SCRIPT := domIntf + script
if !initial {
SCRIPT = script
}
ready := make(chan goja.Value)
errCh := make(chan error)
intCh := make(chan int)
go func() {
d.loop.RunOnLoop(func(vm *goja.Runtime) {
log.Printf("RunOnLoop")
if initial {
vm.SetParserOptions(parser.WithDisableSourceMaps)
// find domino-lib folder
registry := require.NewRegistry(
require.WithGlobalFolders("."),
require.WithLoader(
require.SourceLoader(srcLoader),
),
)
console.Enable(vm)
registry.Enable(vm)
type S struct {
Buf string `json:"buf"`
HTML string `json:"html"`
Referrer func() string `json:"referrer"`
Style func(string, string, string, string) string `json:"style"`
XHR func(string, string, map[string]string, string, func(string, string)) `json:"xhr"`
Mutated func(int, string) `json:"mutated"`
}
vm.SetFieldNameMapper(goja.TagFieldNameMapper("json", true))
vm.Set("opossum", S{
HTML: d.html,
Buf: "yolo",
Referrer: func() string { return "https://example.com" },
Style: func(sel, pseudo, prop, prop2 string) string {
v, err := d.query(sel, prop)
if err != nil {
log.Errorf("devjs: domino: query %v: %v", sel, err)
return ""
}
return v
},
XHR: d.xhr,
Mutated: d.mutated,
})
}
go func() {
for _ = range intCh {
vm.Interrupt("halt")
}
}()
vv, err := vm.RunString(SCRIPT)
if err != nil {
IntrospectError(err, script)
errCh <- fmt.Errorf("run program: %w", err)
} else {
ready <- vv
}
})
}()
for {
select {
case v := <-ready:
log.Infof("ready")
<-time.After(10 * time.Millisecond)
if v != nil {
res = v.String()
}
goto cleanup
case er := <- errCh:
log.Infof("err")
<-time.After(10 * time.Millisecond)
err = fmt.Errorf("event loop: %w", er)
goto cleanup
case <-time.After(timeout):
log.Errorf("Interrupt JS after %v", timeout)
intCh <- 1
}
}
cleanup:
close(ready)
close(errCh)
close(intCh)
return
}
func (d *Domino) Exec6(script string, initial bool) (res string, err error) {
cmd := exec.Command("6to5")
cmd.Stdin = strings.NewReader(script)
var out bytes.Buffer
cmd.Stdout = &out
if err = cmd.Run(); err != nil {
return "", fmt.Errorf("6to5: %w", err)
}
return d.Exec(out.String(), initial)
}
// CloseDoc fires DOMContentLoaded to trigger $(document).ready(..)
func (d *Domino) CloseDoc() (err error) {
_, err = d.Exec("if (this.document) document.close();", false)
return
}
// TriggerClick, and return the result html
// ...then HTML5 parse it, diff the node tree
// (probably faster and cleaner than anything else)
func (d *Domino) TriggerClick(selector string) (newHTML string, ok bool, err error) {
res, err := d.Exec(`
var sel = '` + selector + `';
var el = document.querySelector(sel);
console.log('query ' + sel);
if (!el) {
console.log('el is null/undefined');
//console.log('html:');
//console.log(document.documentElement.innerHTML)
null;
} else if (el._listeners && el._listeners.click) {
var fn = el.click.bind(el);
if (fn) {
console.log(' call click handler...');
fn();
}
!!fn;
} else {
false;
}
`, false)
if ok = res == "true"; ok {
newHTML, ok, err = d.TrackChanges()
}
return
}
// Put change into html (e.g. from input field mutation)
func (d *Domino) PutAttr(selector, attr, val string) (ok bool, err error) {
res, err := d.Exec(`
var sel = '` + selector + `';
var el = document.querySelector(sel);
el.attr('` + attr + `', '` + val + `');
!!el;
`, false)
ok = res == "true"
return
}
func (d *Domino) TrackChanges() (html string, changed bool, err error) {
outer:
for {
// TODO: either add other change types like ajax begin/end or
// just have one channel for all events worth waiting for.
select {
case <-d.domChange:
changed = true
case <-time.After(time.Second):
break outer
}
}
if changed {
html, err = d.Exec("document.querySelector('html').innerHTML;", false)
if err != nil {
return
}
}
d.outputHtml = html
return
}
func (d *Domino) xhr(method, uri string, h map[string]string, data string, cb func(data string, err string)) {
req, err := http.NewRequest(method, /*u.String()*/uri, strings.NewReader(data))
if err != nil {
cb("", err.Error())
return
}
for k, v := range h {
req.Header.Add(k, v)
}
go func() {
resp, err := d.xhrq(req)
if err != nil {
cb("", err.Error())
return
}
//defer resp.Body.Close()
bs, err := ioutil.ReadAll(resp.Body)
if err != nil {
cb("", err.Error())
return
}
d.loop.RunOnLoop(func(*goja.Runtime) {
defer func() {
if r := recover(); r != nil {
log.Errorf("recovered in xhr: %v", r)
}
}()
cb(string(bs), "")
})
}()
}
func (d *Domino) mutated(t int, q string) {
m := Mutation{
Time: time.Now(),
Type: t,
Sel: q,
}
select {
case d.domChange <- m:
default:
log.Printf("dom changes backlog full")
}
}
// AJAX:
// https://stackoverflow.com/questions/7086858/loading-ajax-app-with-jsdom
// Babel on Goja:
// https://github.com/dop251/goja/issues/5#issuecomment-259996573
// Goja supports ES5.1 which is essentially JS assembly:
// https://github.com/dop251/goja/issues/76#issuecomment-399253779