Update docs for CloseStatus

Author: nhooyr

README.md

@@ -33,7 +33,9 @@ go get nhooyr.io/websocket
 
 For a production quality example that shows off the full API, see the [echo example on the godoc](https://godoc.org/nhooyr.io/websocket#example-package--Echo). On github, the example is at [example_echo_test.go](./example_echo_test.go).
 
-Use the [errors.As](https://golang.org/pkg/errors/#As) function [new in Go 1.13](https://golang.org/doc/go1.13#error_wrapping) to check for [websocket.CloseError](https://godoc.org/nhooyr.io/websocket#CloseError). See the [CloseError godoc example](https://godoc.org/nhooyr.io/websocket#example-CloseError).
+Use the [errors.As](https://golang.org/pkg/errors/#As) function [new in Go 1.13](https://golang.org/doc/go1.13#error_wrapping) to check for [websocket.CloseError](https://godoc.org/nhooyr.io/websocket#CloseError).
+There is also [websocket.CloseStatus](https://godoc.org/nhooyr.io/websocket#CloseStatus) to quickly grab the close status code out of a [websocket.CloseError](https://godoc.org/nhooyr.io/websocket#CloseError).
+See the [CloseError godoc example](https://godoc.org/nhooyr.io/websocket#example-CloseError).
 
 ### Server
 

doc.go

@@ -16,6 +16,7 @@
 // comparison with existing implementations.
 //
 // Use the errors.As function new in Go 1.13 to check for websocket.CloseError.
+// Or use the CloseStatus function to grab the StatusCode out of a websocket.CloseError
 // See the CloseError example.
 //
 // Wasm

example_test.go

@@ -4,7 +4,6 @@ package websocket_test
 
 import (
 	"context"
-	"errors"
 	"log"
 	"net/http"
 	"time"
@@ -76,8 +75,7 @@ func ExampleCloseError() {
 	defer c.Close(websocket.StatusInternalError, "the sky is falling")
 
 	_, _, err = c.Reader(ctx)
-	var cerr websocket.CloseError
-	if !errors.As(err, &cerr) || cerr.Code != websocket.StatusNormalClosure {
+	if websocket.CloseStatus(err) != websocket.StatusNormalClosure {
 		log.Fatalf("expected to be disconnected with StatusNormalClosure but got: %+v", err)
 		return
 	}

frame.go

@@ -253,11 +253,11 @@ func (ce CloseError) Error() string {
 	return fmt.Sprintf("status = %v and reason = %q", ce.Code, ce.Reason)
 }
 
-// CloseStatus is a convenience wrapper around xerrors.As to grab
+// CloseStatus is a convenience wrapper around errors.As to grab
 // the status code from a *CloseError. If the passed error is nil
 // or not a *CloseError, the returned StatusCode will be -1.
 func CloseStatus(err error) StatusCode {
-	var ce *CloseError
+	var ce CloseError
 	if errors.As(err, &ce) {
 		return ce.Code
 	}