Preserve asset inspection error causes through delivery

internal/delivery/remote_assets_test.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"os"
 	"reflect"
+	"strings"
 	"testing"
 
 	"go.maximumdirect.net/releasekit/internal/artifact"
@@ -173,6 +174,35 @@ func TestUploadMissingAssetsStopsBeforeWritesForConflictOrUnverifiableContent(t
 	}
 }
 
+func TestUploadMissingAssetsPreservesInspectionCausesAndConflictPrecedence(t *testing.T) {
+	readErr := errors.New("asset download failed")
+	for _, conflict := range []bool{false, true} {
+		name := "unverifiable"
+		if conflict {
+			name = "conflict"
+		}
+		t.Run(name, func(t *testing.T) {
+			backend := &assetBackend{}
+			inspection := Inspection{Assets: []AssetInspection{
+				{Expected: expectedAsset("canceled.bin", []byte("a")), State: AssetUnverifiable, Err: context.Canceled},
+				{Expected: expectedAsset("unreadable.bin", []byte("b")), State: AssetUnverifiable, Err: readErr},
+			}}
+			wantState, wantKind := NotAttempted, forge.FailureUnverifiable
+			if conflict {
+				inspection.Assets = append(inspection.Assets, AssetInspection{Expected: expectedAsset("conflicting.bin", []byte("c")), State: AssetConflicting})
+				wantState, wantKind = Conflict, forge.FailureConflict
+			}
+			result, err := uploadMissingAssets(context.Background(), backend, "release", inspection)
+			if !isForgeFailure(err, wantKind) || result.State != wantState || len(result.Uncertain) != 2 || len(backend.uploadNames) != 0 {
+				t.Fatalf("result = %#v, error %v", result, err)
+			}
+			if !errors.Is(err, context.Canceled) || !errors.Is(err, readErr) || !strings.Contains(err.Error(), "canceled.bin") || !strings.Contains(err.Error(), "unreadable.bin") {
+				t.Fatalf("aggregate lost cause or asset context: %v", err)
+			}
+		})
+	}
+}
+
 func TestUploadMissingAssetsReconcilesOnceAndKeepsLaterAssetsPending(t *testing.T) {
 	assets := []artifact.ExpectedAsset{
 		expectedAsset("a.bin", []byte("a")),