ref: 65ca5e35faf915bf6fe2baa04b100eedf4025985
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 log *logger.Logger 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) } func SetLogger(l *logger.Logger) { log = l } 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*<!--`) script = r.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