Fix/wait log exact number occurences

[FlorianLehmann]

#297

Describe the bug
When I define

NewLogStrategy("").
WithStartupTimeout(100 * time.Microsecond).
WithOccurrence(X)

for a container, it does not wait for X occurences. One occurence is enough to continue.

To Reproduce

func TestWaitShouldFailWithExactNumberOfOccurrences(t *testing.T) {
	target := noopStrategyTarget{
		ioReaderCloser: ioutil.NopCloser(bytes.NewReader([]byte("hello\r\ndude"))),
	}
	wg := NewLogStrategy("dude").
		WithStartupTimeout(100 * time.Microsecond).
		WithOccurrence(2)
	err := wg.WaitUntilReady(context.Background(), target)
	if err == nil {
		t.Fatal("expected error")
	}
}

Expected behavior
it must wait for X occurences in the logs.

Additional context

testcontainers-go/wait/log.go

Lines 75 to 95 in 6467d9b

	currentOccurence := 0
	LOOP:
	for {
	select {
	case <-ctx.Done():
	return ctx.Err()
	default:
	reader, err := target.Logs(ctx)
	if err != nil {
	time.Sleep(ws.PollInterval)
	continue
	}
	b, err := ioutil.ReadAll(reader)
	logs := string(b)
	if strings.Contains(logs, ws.Log) {
	currentOccurence++
	if ws.Occurrence == 0 || currentOccurence >= ws.Occurrence-1 {
	break LOOP
	}

There is a variable currentOccurence defined before the loop. This variable is incremented in the loop each time the expected log appears. However, logs are read from the beginning. Therefore, the condition based on the number of occurences is always true if the expected log is present only once.

[codecov]

Codecov Report

Merging #298 (0b93d46) into master (6467d9b) will decrease coverage by 1.21%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #298      +/-   ##
==========================================
- Coverage   64.04%   62.82%   -1.22%     
==========================================
  Files          13       13              
  Lines         865      877      +12     
==========================================
- Hits          554      551       -3     
- Misses        226      242      +16     
+ Partials       85       84       -1     

Impacted Files	Coverage Δ
wait/log.go	75.75% <100.00%> (-2.03%)	⬇️
wait/host_port.go	56.14% <0.00%> (-4.28%)	⬇️
wait/http.go	56.04% <0.00%> (-1.43%)	⬇️
docker.go	65.20% <0.00%> (-0.62%)	⬇️
wait/sql.go	0.00% <0.00%> (ø)

---

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[gianarb]

Thanks a lot for your work and sorry if it took me some time