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// untested sections: 1
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package gbytes
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import (
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	"fmt"
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	"regexp"
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	"github.com/onsi/gomega/format"
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)
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// Objects satisfying the BufferProvider can be used with the Say matcher.
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type BufferProvider interface {
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	Buffer() *Buffer
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}
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/*
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Say is a Gomega matcher that operates on gbytes.Buffers:
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	Expect(buffer).Should(Say("something"))
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will succeed if the unread portion of the buffer matches the regular expression "something".
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When Say succeeds, it fast forwards the gbytes.Buffer's read cursor to just after the successful match.
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Thus, subsequent calls to Say will only match against the unread portion of the buffer
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Say pairs very well with Eventually.  To assert that a buffer eventually receives data matching "[123]-star" within 3 seconds you can:
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	Eventually(buffer, 3).Should(Say("[123]-star"))
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Ditto with consistently.  To assert that a buffer does not receive data matching "never-see-this" for 1 second you can:
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	Consistently(buffer, 1).ShouldNot(Say("never-see-this"))
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In addition to bytes.Buffers, Say can operate on objects that implement the gbytes.BufferProvider interface.
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In such cases, Say simply operates on the *gbytes.Buffer returned by Buffer()
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If the buffer is closed, the Say matcher will tell Eventually to abort.
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*/
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func Say(expected string, args ...any) *sayMatcher {
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	if len(args) > 0 {
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		expected = fmt.Sprintf(expected, args...)
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	}
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	return &sayMatcher{
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		re: regexp.MustCompile(expected),
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	}
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}
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type sayMatcher struct {
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	re              *regexp.Regexp
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	receivedSayings []byte
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}
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func (m *sayMatcher) buffer(actual any) (*Buffer, bool) {
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	var buffer *Buffer
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	switch x := actual.(type) {
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	case *Buffer:
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		buffer = x
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	case BufferProvider:
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		buffer = x.Buffer()
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	default:
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		return nil, false
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	}
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	return buffer, true
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}
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func (m *sayMatcher) Match(actual any) (success bool, err error) {
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	buffer, ok := m.buffer(actual)
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	if !ok {
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		return false, fmt.Errorf("Say must be passed a *gbytes.Buffer or BufferProvider.  Got:\n%s", format.Object(actual, 1))
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	}
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	didSay, sayings := buffer.didSay(m.re)
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	m.receivedSayings = sayings
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	return didSay, nil
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}
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func (m *sayMatcher) FailureMessage(actual any) (message string) {
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	return fmt.Sprintf(
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		"Got stuck at:\n%s\nWaiting for:\n%s",
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		format.IndentString(string(m.receivedSayings), 1),
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		format.IndentString(m.re.String(), 1),
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	)
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}
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func (m *sayMatcher) NegatedFailureMessage(actual any) (message string) {
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	return fmt.Sprintf(
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		"Saw:\n%s\nWhich matches the unexpected:\n%s",
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		format.IndentString(string(m.receivedSayings), 1),
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		format.IndentString(m.re.String(), 1),
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	)
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}
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func (m *sayMatcher) MatchMayChangeInTheFuture(actual any) bool {
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	switch x := actual.(type) {
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	case *Buffer:
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		return !x.Closed()
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	case BufferProvider:
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		return !x.Buffer().Closed()
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	default:
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		return true
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	}
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}
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