Preserve comparison failures during cancellation

internal/app/comparison_test.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -307,6 +308,57 @@ func TestCompareDetailedCancellationPreservesPublishedBundle(t *testing.T) {
 	}
 }
 
+func TestCompareDetailedPreservesCompletedProfileFailureWhenCanceled(t *testing.T) {
+	bundle := generationBundle(t)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	failureStarted := make(chan struct{})
+	var signalFailure sync.Once
+	executor := &generationExecutor{
+		validations:         map[string]promptexec.ValidationStatus{"weather-light": promptexec.ValidationFailed},
+		waitForCancellation: map[string]bool{"weather-deep": true},
+		beforeExecute: func(request promptexec.ExecuteRequest) {
+			if request.ProfileID == "weather-light" {
+				signalFailure.Do(func() { close(failureStarted) })
+			}
+		},
+	}
+	results := make(chan struct {
+		result *ComparisonResult
+		err    error
+	}, 1)
+	go func() {
+		result, err := CompareDetailed(ctx, ComparisonRequest{
+			Config: comparisonConfig(), Report: ReportDaily, ProfileIDs: []string{"weather-light", "weather-deep"},
+			WorkingDir: t.TempDir(), Date: generationTime("2026-05-29T12:00:00-05:00"),
+			Clock:     timeutil.FixedClock{Time: generationTime("2026-05-29T08:30:00-05:00")},
+			Collector: &generationCollector{bundle: &bundle}, Executor: executor,
+		})
+		results <- struct {
+			result *ComparisonResult
+			err    error
+		}{result: result, err: err}
+	}()
+
+	select {
+	case <-failureStarted:
+		cancel()
+	case <-time.After(5 * time.Second):
+		t.Fatal("timed out waiting for the completed profile failure")
+	}
+	completed := <-results
+	if !errors.Is(completed.err, context.Canceled) || completed.result == nil || completed.result.ManifestPath != "" || completed.result.DataPackagePath != "" || completed.result.Succeeded != 0 || completed.result.Failed != 2 {
+		t.Fatalf("CompareDetailed() result/error = %#v/%v", completed.result, completed.err)
+	}
+	failed, canceled := completed.result.Results[0], completed.result.Results[1]
+	if failed.Error == nil || failed.Error.Category != string(promptexec.ValidationRejected) || failed.ValidationStatus != promptexec.ValidationFailed || failed.ReportPath != "" {
+		t.Fatalf("completed failure = %#v", failed)
+	}
+	if canceled.Error == nil || canceled.Error.Category != string(promptexec.Canceled) || canceled.ValidationStatus != promptexec.ValidationSkipped || canceled.ReportPath != "" {
+		t.Fatalf("canceled profile = %#v", canceled)
+	}
+}
+
 func TestCompareDetailedLeavesExistingBundleWhenPublicationPreflightChanges(t *testing.T) {
 	workingDir := t.TempDir()
 	target := filepath.Join(workingDir, "comparison-output")