Enforce durable D&D evidence ranges

internal/modules/dnd/codec/npcregistry/codec.go

@@ -8,6 +8,7 @@ import (
 	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/codec/candidatejson"
+	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/codec/sourcerange"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/npcs/identity"
 )
 
@@ -99,11 +100,8 @@ func validate(value dnd.NPCRegistry) error {
 			if strings.TrimSpace(ref.SourceID) == "" {
 				return fmt.Errorf("%s.source_id must not be empty", refPrefix)
 			}
-			if ref.StartUnitID <= 0 {
-				return fmt.Errorf("%s.start_unit_id must be positive", refPrefix)
-			}
-			if ref.EndUnitID <= 0 {
-				return fmt.Errorf("%s.end_unit_id must be positive", refPrefix)
+			if err := sourcerange.Validate(ref); err != nil {
+				return fmt.Errorf("%s: %w", refPrefix, err)
 			}
 		}
 	}

internal/modules/dnd/codec/npcregistry/codec_test.go

@@ -112,6 +112,41 @@ func TestCodecCandidatePreservesInvalidTypedValues(t *testing.T) {
 	}
 }
 
+func TestCodecRejectsInvalidDurableRangesWhileCandidatesPreserveThem(t *testing.T) {
+	codec := New()
+	for _, test := range []struct {
+		name   string
+		mutate func(*dnd.NPCRegistry)
+		want   string
+	}{
+		{name: "nonpositive start", mutate: func(value *dnd.NPCRegistry) { value.NPCs[0].SourceRefs[0].StartUnitID = 0 }, want: "start_unit_id"},
+		{name: "nonpositive end", mutate: func(value *dnd.NPCRegistry) { value.NPCs[0].SourceRefs[0].EndUnitID = 0 }, want: "end_unit_id"},
+		{name: "reversed", mutate: func(value *dnd.NPCRegistry) {
+			value.NPCs[0].SourceRefs[0].StartUnitID = 2
+			value.NPCs[0].SourceRefs[0].EndUnitID = 1
+		}, want: "must not exceed"},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			candidate := validList()
+			test.mutate(&candidate)
+			content, err := codec.EncodeCandidate(candidate)
+			if err != nil {
+				t.Fatalf("EncodeCandidate() error = %v", err)
+			}
+			decoded, err := codec.DecodeCandidate(content)
+			if err != nil || !reflect.DeepEqual(decoded, candidate) {
+				t.Fatalf("DecodeCandidate() = %#v, %v; want %#v", decoded, err, candidate)
+			}
+			if _, err := codec.Encode(candidate); err == nil || !strings.Contains(err.Error(), test.want) {
+				t.Fatalf("Encode() error = %v, want %q", err, test.want)
+			}
+			if _, err := codec.Decode(content); err == nil || !strings.Contains(err.Error(), test.want) {
+				t.Fatalf("Decode() error = %v, want %q", err, test.want)
+			}
+		})
+	}
+}
+
 func TestCodecCandidateDecodeOwnsValues(t *testing.T) {
 	codec := New()
 	input := validList()