Close deferred reporting before final delivery

reporter.go

@@ -36,15 +36,16 @@ const (
 )
 
 type reportingState struct {
-	mu          sync.Mutex
-	output      destinationState
-	diagnostics destinationState
-	closed      bool
-	mode        reportingMode
-	format      Format
-	progress    bool
-	progressSet bool
-	deferred    []deferredMessage
+	mu             sync.Mutex
+	output         destinationState
+	diagnostics    destinationState
+	closed         bool
+	deferredClosed bool
+	mode           reportingMode
+	format         Format
+	progress       bool
+	progressSet    bool
+	deferred       []deferredMessage
 }
 
 type destinationState struct {
@@ -78,8 +79,8 @@ type Reporter struct {
 }
 
 // DeferredReporter queues messages for delivery during invocation finalization.
-// Copies share the same invocation reporting state. Submissions made after
-// finalization return ErrReporterClosed.
+// Copies share the same invocation reporting state. Submissions return
+// ErrReporterClosed once finalization begins, before the accepted batch is delivered.
 type DeferredReporter struct {
 	state *reportingState
 }
@@ -222,7 +223,8 @@ func (r *Reporter) Progress(message string, details ...Detail) error {
 
 // AtEnd returns a view for messages delivered after the handler returns and
 // before terminal explanation delivery. The deferred view shares this
-// invocation's state.
+// invocation's state. Acceptance ends when finalization begins, before queued
+// messages are delivered.
 func (r *Reporter) AtEnd() DeferredReporter {
 	if r == nil {
 		return DeferredReporter{}
@@ -258,7 +260,7 @@ func (r DeferredReporter) enqueue(category messageCategory, message string, deta
 	state := r.state
 	state.mu.Lock()
 	defer state.mu.Unlock()
-	if state.closed {
+	if state.closed || state.deferredClosed {
 		return ErrReporterClosed
 	}
 	if !hasDetails(details) {
@@ -290,6 +292,7 @@ func (r *Reporter) finalize(outcome Outcome, completion func(*Reporter)) Outcome
 		state.mu.Unlock()
 		return normalizeOutcome(outcome)
 	}
+	state.deferredClosed = true
 	deferred := state.deferred
 	state.deferred = nil
 	state.mu.Unlock()
@@ -664,23 +667,3 @@ func (state *reportingState) deliveryResultLocked(destination reportingDestinati
 	}
 	return result
 }
-
-func (r *Reporter) setVisibility(mode reportingMode, progress bool, progressSet bool) {
-	if r == nil || r.state == nil {
-		return
-	}
-	r.state.mu.Lock()
-	r.state.mode = mode
-	r.state.progress = progress
-	r.state.progressSet = progressSet
-	r.state.mu.Unlock()
-}
-
-func (r *Reporter) close() {
-	if r == nil || r.state == nil {
-		return
-	}
-	r.state.mu.Lock()
-	r.state.closed = true
-	r.state.mu.Unlock()
-}