package main

import (
	"fmt"
	"html"
	"log"
	"net"
	"net/http"
	"testing"
	"unicode/utf8"
)

func FuzzReverse(f *testing.F) {
	// Uncomment either runHTTPServer or runTCPServer to make test fuzz
	// fail.
	go runHTTPServer()
	//go runTCPServer()
	testcases := []string{"Hello, world", " ", "!12345"}
	for _, tc := range testcases {
		f.Add(tc) // Use f.Add to provide a seed corpus
	}
	f.Fuzz(func(t *testing.T, orig string) {
		rev, err1 := Reverse(orig)
		if err1 != nil {
			return
		}
		doubleRev, err2 := Reverse(rev)
		if err2 != nil {
			return
		}
		if orig != doubleRev {
			t.Errorf("Before: %q, after: %q", orig, doubleRev)
		}
		if utf8.ValidString(orig) && !utf8.ValidString(rev) {
			t.Errorf("Reverse produced invalid UTF-8 string %q", rev)
		}
	})
}

func runHTTPServer() {
	http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))
	})

	log.Fatal(http.ListenAndServe(":18080", nil))
}

func runTCPServer() {
	ln, err := net.Listen("tcp", ":18081")
	if err != nil {
		log.Fatal(`runTCPServer:`, err)
	}
	for {
		_, err := ln.Accept()
		if err != nil {
			log.Fatal(`runTCPServer: Accept`, err)
		}
	}
}

$ go test -fuzz=. -run=none -fuzztime=10s -v
=== RUN   FuzzReverse
fuzz: elapsed: 0s, gathering baseline coverage: 0/46 completed
fuzz: elapsed: 0s, gathering baseline coverage: 0/46 completed
--- FAIL: FuzzReverse (0.02s)
    fuzzing process terminated without fuzzing: EOF
=== NAME  
FAIL
exit status 1
FAIL    git.sr.ht/~shulhan/sandbox.go/fuzz      0.021s

	//go runHTTPServer()
	//go runTCPServer()

$ go test -fuzz=. -run=none -fuzztime=10s -v                                                                      
=== RUN   FuzzReverse                                                                                                   
fuzz: elapsed: 0s, gathering baseline coverage: 0/46 completed
fuzz: elapsed: 0s, gathering baseline coverage: 46/46 completed, now fuzzing with 4 workers
fuzz: elapsed: 3s, execs: 130236 (43416/sec), new interesting: 0 (total: 46)
fuzz: elapsed: 6s, execs: 255613 (41785/sec), new interesting: 0 (total: 46)
fuzz: elapsed: 9s, execs: 387455 (43941/sec), new interesting: 0 (total: 46)
fuzz: elapsed: 10s, execs: 431389 (40198/sec), new interesting: 0 (total: 46)
--- PASS: FuzzReverse (10.10s) 
=== NAME  
PASS
ok      git.sr.ht/~shulhan/sandbox.go/fuzz      10.107s