Cleaning up runner API prior to package rewrite

chromedp.go

@@ -90,7 +90,7 @@ func New(ctxt context.Context, opts ...Option) (*CDP, error) {
 
 	// watch handlers
 	if c.watch == nil {
-		c.watch = c.r.WatchPageTargets(ctxt)
+		c.watch = c.r.Client().WatchPageTargets(ctxt)
 	}
 
 	go func() {

pool.go

@@ -74,7 +74,11 @@ func (p *Pool) Allocate(ctxt context.Context, opts ...runner.CommandLineOption)
 
 	// create runner
 	r.r, err = runner.New(append([]runner.CommandLineOption{
-		runner.HeadlessPathPort("", r.port),
+		runner.ExecPath(runner.LookChromeNames("headless_shell")),
+		runner.RemoteDebuggingPort(r.port),
+		runner.NoDefaultBrowserCheck,
+		runner.NoFirstRun,
+		runner.Headless,
 	}, opts...)...)
 	if err != nil {
 		defer r.Release()

runner/path_darwin.go

@@ -3,10 +3,11 @@
 package runner
 
 const (
-	// DefaultChromePath is the default path to the Chrome application.
+	// DefaultChromePath is the default path to use for Chrome if the
+	// executable is not in $PATH.
 	DefaultChromePath = `/Applications/Google Chrome.app/Contents/MacOS/Google Chrome`
 )
 
-func findChromePath() string {
+// DefaultChromeNames are the default Chrome executable names to look for in
-	return DefaultChromePath
+// $PATH.
-}
+var DefaultChromeNames []string

runner/path_unix.go

@@ -2,30 +2,18 @@
 
 package runner
 
-import "os/exec"
-
 const (
-	// DefaultChromePath is the default path to the google-chrome executable if
+	// DefaultChromePath is the default path to use for Chrome if the
-	// a variant cannot be found on $PATH.
+	// executable is not in $PATH.
 	DefaultChromePath = "/usr/bin/google-chrome"
 )
 
-// chromeNames are the Chrome executable names to search for in the path.
+// DefaultChromeNames are the default Chrome executable names to look for in
-var chromeNames = []string{
+// $PATH.
+var DefaultChromeNames = []string{
 	"google-chrome",
 	"chromium-browser",
 	"chromium",
 	"google-chrome-beta",
 	"google-chrome-unstable",
 }
-
-func findChromePath() string {
-	for _, p := range chromeNames {
-		path, err := exec.LookPath(p)
-		if err == nil {
-			return path
-		}
-	}
-
-	return DefaultChromePath
-}

runner/path_windows.go

@@ -2,32 +2,12 @@
 
 package runner
 
-import "os/exec"
-
 const (
-	// DefaultChromePath is the default path to use for Google Chrome if the
+	// DefaultChromePath is the default path to use for Chrome if the
 	// executable is not in %PATH%.
 	DefaultChromePath = `C:\Program Files (x86)\Google\Chrome\Application\chrome.exe`
-
-	// DefaultEdgeDiagnosticsAdapterPath is the default path to use for the
-	// Microsoft Edge Diagnostics Adapter if the executable is not in %PATH%.
-	DefaultEdgeDiagnosticsAdapterPath = `c:\Edge\EdgeDiagnosticsAdapter\x64\EdgeDiagnosticsAdapter.exe`
 )
 
-func findChromePath() string {
+// DefaultChromeNames are the default Chrome executable names to look for in
-	path, err := exec.LookPath(`chrome.exe`)
+// %PATH%.
-	if err == nil {
+var DefaultChromeNames = []string{`chrome.exe`}
-		return path
-	}
-
-	return DefaultChromePath
-}
-
-func findEdgePath() string {
-	path, err := exec.LookPath(`EdgeDiagnosticsAdapter.exe`)
-	if err == nil {
-		return path
-	}
-
-	return DefaultEdgeDiagnosticsAdapterPath
-}

runner/runner.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"fmt"
 	"io/ioutil"
-	"net/url"
 	"os"
 	"os/exec"
 	"regexp"
@@ -16,6 +15,11 @@ import (
 	"github.com/chromedp/chromedp/client"
 )
 
+const (
+	// DefaultUserDataDirPrefix is the default user data directory prefix.
+	DefaultUserDataDirPrefix = "chromedp-runner.%d."
+)
+
 // Error is a runner error.
 type Error string
 
@@ -32,19 +36,17 @@ const (
 	// ErrAlreadyWaiting is the already waiting error.
 	ErrAlreadyWaiting Error = "already waiting"
 
+	// ErrInvalidURLs is the invalid url-opts error.
+	ErrInvalidURLOpts Error = "invalid url-opts"
+
 	// ErrInvalidCmdOpts is the invalid cmd-opts error.
 	ErrInvalidCmdOpts Error = "invalid cmd-opts"
 
 	// ErrInvalidProcessOpts is the invalid process-opts error.
 	ErrInvalidProcessOpts Error = "invalid process-opts"
 
-	// ErrExecPathNotSet is the exec-path not set set error.
+	// ErrInvalidExecPath is the invalid exec-path error.
-	ErrExecPathNotSet Error = "exec-path command line option not set, or chrome executable not found in PATH"
+	ErrInvalidExecPath Error = "invalid exec-path"
-)
-
-const (
-	// DefaultUserDataDirPrefix is the default user data directory prefix.
-	DefaultUserDataDirPrefix = "chromedp-runner.%d."
 )
 
 // Runner holds information about a running Chrome process.
@@ -59,19 +61,18 @@ type Runner struct {
 func New(opts ...CommandLineOption) (*Runner, error) {
 	var err error
 
-	cliOpts := map[string]interface{}{}
+	cliOpts := make(map[string]interface{})
 
 	// apply opts
 	for _, o := range opts {
-		err = o(cliOpts)
+		if err = o(cliOpts); err != nil {
-		if err != nil {
 			return nil, err
 		}
 	}
 
 	// set default Chrome options if exec-path not provided
 	if _, ok := cliOpts["exec-path"]; !ok {
-		cliOpts["exec-path"] = findChromePath()
+		cliOpts["exec-path"] = LookChromeNames()
 		for k, v := range map[string]interface{}{
 			"no-first-run":             true,
 			"no-default-browser-check": true,
@@ -86,8 +87,7 @@ func New(opts ...CommandLineOption) (*Runner, error) {
 	// add KillProcessGroup and ForceKill if no other cmd opts provided
 	if _, ok := cliOpts["cmd-opts"]; !ok {
 		for _, o := range []CommandLineOption{KillProcessGroup, ForceKill} {
-			err = o(cliOpts)
+			if err = o(cliOpts); err != nil {
-			if err != nil {
 				return nil, err
 			}
 		}
@@ -104,9 +104,9 @@ var cliOptRE = regexp.MustCompile(`^[a-z0-9\-]+$`)
 // buildOpts generates the command line options for Chrome.
 func (r *Runner) buildOpts() []string {
 	var opts []string
+	var urls []string
 
-	// process options
+	// process opts
-	var urlstr string
 	for k, v := range r.opts {
 		if !cliOptRE.MatchString(k) || v == nil {
 			continue
@@ -116,8 +116,8 @@ func (r *Runner) buildOpts() []string {
 		case "exec-path", "cmd-opts", "process-opts":
 			continue
 
-		case "start-url":
+		case "url-opts":
-			urlstr = v.(string)
+			urls = v.([]string)
 
 		default:
 			switch z := v.(type) {
@@ -135,16 +135,16 @@ func (r *Runner) buildOpts() []string {
 		}
 	}
 
-	if urlstr == "" {
+	if urls == nil {
-		urlstr = "about:blank"
+		urls = append(urls, "about:blank")
 	}
 
-	return append(opts, urlstr)
+	return append(opts, urls...)
 }
 
 // Start starts a Chrome process using the specified context. The Chrome
 // process can be terminated by closing the passed context.
-func (r *Runner) Start(ctxt context.Context) error {
+func (r *Runner) Start(ctxt context.Context, opts ...string) error {
 	var err error
 	var ok bool
 
@@ -156,11 +156,6 @@ func (r *Runner) Start(ctxt context.Context) error {
 		return ErrAlreadyStarted
 	}
 
-	// setup context
-	if ctxt == nil {
-		ctxt = context.Background()
-	}
-
 	// set user data dir, if not provided
 	_, ok = r.opts["user-data-dir"]
 	if !ok {
@@ -172,36 +167,41 @@ func (r *Runner) Start(ctxt context.Context) error {
 		}
 	}
 
-	// ensure exec-path set
+	// get exec path
-	execPath, ok := r.opts["exec-path"]
+	var execPath string
-	if !ok {
+	if p, ok := r.opts["exec-path"]; ok {
-		return ErrExecPathNotSet
+		execPath, ok = p.(string)
+		if !ok {
+			return ErrInvalidExecPath
+		}
+	}
+
+	// ensure execPath is valid
+	if execPath == "" {
+		return ErrInvalidExecPath
 	}
 
 	// create cmd
-	r.cmd = exec.CommandContext(ctxt, execPath.(string), r.buildOpts()...)
+	r.cmd = exec.CommandContext(ctxt, execPath, append(r.buildOpts(), opts...)...)
 
 	// apply cmd opts
 	if cmdOpts, ok := r.opts["cmd-opts"]; ok {
 		for _, co := range cmdOpts.([]func(*exec.Cmd) error) {
-			err = co(r.cmd)
+			if err = co(r.cmd); err != nil {
-			if err != nil {
 				return err
 			}
 		}
 	}
 
 	// start process
-	err = r.cmd.Start()
+	if err = r.cmd.Start(); err != nil {
-	if err != nil {
 		return err
 	}
 
 	// apply process opts
 	if processOpts, ok := r.opts["process-opts"]; ok {
 		for _, po := range processOpts.([]func(*os.Process) error) {
-			err = po(r.cmd.Process)
+			if err = po(r.cmd.Process); err != nil {
-			if err != nil {
 				// TODO: do something better here, as we want to kill
 				// the child process, do cleanup, etc.
 				panic(err)
@@ -305,12 +305,6 @@ func (r *Runner) Client(opts ...client.Option) *client.Client {
 	)...)
 }
 
-// WatchPageTargets returns a channel that will receive new page targets as
-// they are created.
-func (r *Runner) WatchPageTargets(ctxt context.Context, opts ...client.Option) <-chan client.Target {
-	return r.Client(opts...).WatchPageTargets(ctxt)
-}
-
 // Run starts a new Chrome process runner, using the provided context and
 // command line options.
 func Run(ctxt context.Context, opts ...CommandLineOption) (*Runner, error) {
@@ -323,20 +317,19 @@ func Run(ctxt context.Context, opts ...CommandLineOption) (*Runner, error) {
 	}
 
 	// start
-	err = r.Start(ctxt)
+	if err = r.Start(ctxt); err != nil {
-	if err != nil {
 		return nil, err
 	}
 
 	return r, nil
 }
 
-// CommandLineOption is a Chrome command line option.
+// CommandLineOption is a runner command line option.
 //
 // see: http://peter.sh/experiments/chromium-command-line-switches/
 type CommandLineOption func(map[string]interface{}) error
 
-// Flag is a generic Chrome command line option to pass a name=value flag to
+// Flag is a generic command line option to pass a name=value flag to
 // Chrome.
 func Flag(name string, value interface{}) CommandLineOption {
 	return func(m map[string]interface{}) error {
@@ -360,33 +353,12 @@ func Path(path string) CommandLineOption {
 	}
 }
 
-// HeadlessPathPort is the Chrome command line option to set the default
+// ExecPath is a command line option to set the exec path.
-// settings for running the headless_shell executable. If path is empty, then
-// an attempt will be made to find headless_shell on the path.
-func HeadlessPathPort(path string, port int) CommandLineOption {
-	if path == "" {
-		path, _ = exec.LookPath("headless_shell")
-	}
-
-	return func(m map[string]interface{}) error {
-		m["exec-path"] = path
-		m["remote-debugging-port"] = port
-		m["headless"] = true
-		return nil
-	}
-}
-
-// ExecPath is a Chrome command line option to set the exec path.
 func ExecPath(path string) CommandLineOption {
 	return Flag("exec-path", path)
 }
 
-// Port is the Chrome command line option to set the remote debugging port.
+// UserDataDir is the command line option to set the user data dir.
-func Port(port int) CommandLineOption {
-	return Flag("remote-debugging-port", port)
-}
-
-// UserDataDir is the Chrome command line option to set the user data dir.
 //
 // Note: set this option to manually set the profile directory used by Chrome.
 // When this is not set, then a default path will be created in the /tmp
@@ -395,27 +367,17 @@ func UserDataDir(dir string) CommandLineOption {
 	return Flag("user-data-dir", dir)
 }
 
-// StartURL is the Chrome command line option to set the initial URL.
+// ProxyServer is the command line option to set the outbound proxy server.
-func StartURL(urlstr string) CommandLineOption {
+func ProxyServer(proxy string) CommandLineOption {
-	return Flag("start-url", urlstr)
-}
-
-// Proxy is the Chrome command line option to set the outbound proxy.
-func Proxy(proxy string) CommandLineOption {
 	return Flag("proxy-server", proxy)
 }
 
-// ProxyPacURL is the Chrome command line option to set the URL of a proxy PAC file.
+// WindowSize is the command line option to set the initial window size.
-func ProxyPacURL(pacURL url.URL) CommandLineOption {
-	return Flag("proxy-pac-url", pacURL.String())
-}
-
-// WindowSize is the Chrome command line option to set the initial window size.
 func WindowSize(width, height int) CommandLineOption {
 	return Flag("window-size", fmt.Sprintf("%d,%d", width, height))
 }
 
-// UserAgent is the Chrome command line option to set the default User-Agent
+// UserAgent is the command line option to set the default User-Agent
 // header.
 func UserAgent(userAgent string) CommandLineOption {
 	return Flag("user-agent", userAgent)
@@ -438,45 +400,83 @@ func NoDefaultBrowserCheck(m map[string]interface{}) error {
 	return Flag("no-default-browser-check", true)(m)
 }
 
-// DisableGPU is the Chrome command line option to disable the GPU process.
+// RemoteDebuggingPort is the command line option to set the remote
+// debugging port.
+func RemoteDebuggingPort(port int) CommandLineOption {
+	return Flag("remote-debugging-port", port)
+}
+
+// Headless is the command line option to run in headless mode.
+func Headless(m map[string]interface{}) error {
+	return Flag("headless", true)(m)
+}
+
+// DisableGPU is the command line option to disable the GPU process.
 func DisableGPU(m map[string]interface{}) error {
 	return Flag("disable-gpu", true)(m)
 }
 
-// CmdOpt is a Chrome command line option to modify the underlying exec.Cmd
+// URL is the command line option to add a URL to open on process start.
-// prior to invocation.
+//
+// Note: this can be specified multiple times, and each URL will be opened in a
+// new tab.
+func URL(urlstr string) CommandLineOption {
+	return func(m map[string]interface{}) error {
+		var urls []string
+		if u, ok := m["url-opts"]; ok {
+			urls, ok = u.([]string)
+			if !ok {
+				return ErrInvalidURLOpts
+			}
+		}
+		m["url-opts"] = append(urls, urlstr)
+		return nil
+	}
+}
+
+// CmdOpt is a command line option to modify the underlying exec.Cmd
+// prior to the call to exec.Cmd.Start in Run.
 func CmdOpt(o func(*exec.Cmd) error) CommandLineOption {
 	return func(m map[string]interface{}) error {
 		var opts []func(*exec.Cmd) error
-
 		if e, ok := m["cmd-opts"]; ok {
 			opts, ok = e.([]func(*exec.Cmd) error)
 			if !ok {
 				return ErrInvalidCmdOpts
 			}
 		}
-
 		m["cmd-opts"] = append(opts, o)
-
 		return nil
 	}
 }
 
-// ProcessOpt is a Chrome command line option to modify the child os.Process
+// ProcessOpt is a command line option to modify the child os.Process
-// after started exec.Cmd.Start.
+// after the call to exec.Cmd.Start in Run.
 func ProcessOpt(o func(*os.Process) error) CommandLineOption {
 	return func(m map[string]interface{}) error {
 		var opts []func(*os.Process) error
-
 		if e, ok := m["process-opts"]; ok {
 			opts, ok = e.([]func(*os.Process) error)
 			if !ok {
 				return ErrInvalidProcessOpts
 			}
 		}
-
 		m["process-opts"] = append(opts, o)
-
 		return nil
 	}
 }
+
+// LookChromeNames looks for the platform's DefaultChromeNames and any
+// additional names using exec.LookPath, returning the first encountered
+// location or the platform's DefaultChromePath if no names are found on the
+// path.
+func LookChromeNames(additional ...string) string {
+	for _, p := range append(additional, DefaultChromeNames...) {
+		path, err := exec.LookPath(p)
+		if err == nil {
+			return path
+		}
+	}
+
+	return DefaultChromePath
+}