Add CloseRead and closeError test

[nhooyr]

@scsmithr so I added a test for the issue you reported to me.

It passes. Does your code look any different?

[codecov]

Codecov Report

Merging #99 into master will decrease coverage by 0.62%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master      #99      +/-   ##
==========================================
- Coverage   76.48%   75.86%   -0.63%     
==========================================
  Files          13       13              
  Lines         978      986       +8     
==========================================
  Hits          748      748              
- Misses        176      184       +8     
  Partials       54       54

Impacted Files	Coverage Δ
websocket.go	70.72% <0%> (-1.24%)	⬇️

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[nhooyr]

Whoops meant to notify you. @scsmithr

[scsmithr]

So it turns out I was just misplacing a defer cancel().

If I change your "closeError" test to the following, I get the EOF.

server: func(w http.ResponseWriter, r *http.Request) error {
	c, err := websocket.Accept(w, r, websocket.AcceptOptions{})
	if err != nil {
		return err
	}
	defer c.Close(websocket.StatusInternalError, "")

	ctx, cancel := context.WithCancel(r.Context())
	defer cancel()

	go func() {
		defer cancel()
		c.Reader(ctx)
		c.Close(websocket.StatusPolicyViolation, "")
	}()

	err = wsjson.Write(ctx, c, "hello")
	if err != nil {
		return err
	}

	return nil
},

Removing the extra defer cancel() fixes it.

[nhooyr]

Makes sense, you're closing the connection early with the defer before the close frame can be written.