B5g3-5: the tool runner receives a chunked seat answer and hands the bundle the whole

Builds: design 47 G §681, §712, A-237, A-249, A-139

Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h

node-tools/internal/bus/chunked_test.go

@@ -0,0 +1,75 @@
+package bus_test
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"testing"
+
+	"github.com/nats-io/nats.go"
+
+	"git.novox.be/novox/mesh-sdk/go/buscalls"
+	mt "github.com/novox/mesh-tools/node-tools/internal/meshtest"
+)
+
+// Design 47 G A-249, §681: the runner asks a chunked verb with a call token of its own, receives the chunks the answer counts
+// (each acknowledged before the next) and answers the verb's own answer with the whole file, so the asker receives none.
+func TestAChunkedSeatAnswerIsReceivedByTheRunnerAndHandedWhole(t *testing.T) {
+	url := mt.URL(t)
+	holder := dial(t, url, "mesh-delivery-indexer", "anchor", "")
+	asker := dial(t, url, "mesh-build-go", "anchor", "")
+	raw, err := nats.Connect(url)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(raw.Close)
+	file := make([]byte, buscalls.SeatChunkBytes*2+5)
+	for i := range file {
+		file[i] = byte(i)
+	}
+	// the holder's process: answers the count, then sends each chunk and waits for its acknowledgement
+	stop, err := holder.Handle("seat:mesh-catalog.input", func(body json.RawMessage) (any, error) {
+		var in struct{ Call, Digest string }
+		if err := json.Unmarshal(body, &in); err != nil || in.Call == "" {
+			t.Errorf("the verb was asked with no call token: %s (%v)", body, err)
+			return nil, err
+		}
+		send := buscalls.SeatChunks{Seat: "mesh-catalog", Verb: "input", Call: in.Call}
+		go func() {
+			for n := int64(1); n <= 3; n++ {
+				end := min(int64(len(file)), n*buscalls.SeatChunkBytes)
+				data, _ := json.Marshal(buscalls.SeatChunk{N: n, Of: 3, Data: file[(n-1)*buscalls.SeatChunkBytes : end]})
+				ackSub, _ := raw.SubscribeSync(send.Ack(n))
+				_ = raw.Flush()
+				if err := raw.Publish(send.Chunk(n), data); err != nil {
+					return
+				}
+				m, err := ackSub.NextMsg(buscalls.SeatAckWithin)
+				if err != nil {
+					t.Errorf("chunk %d not acknowledged: %v", n, err)
+					return
+				}
+				_ = m.Respond([]byte("{}"))
+			}
+		}()
+		return map[string]any{"digest": in.Digest, "chunks": 3}, nil
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer stop()
+	got, err := asker.AskAsChunked("mesh-build-go", "seat:mesh-catalog.input", map[string]any{"digest": "d1"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	var ans struct {
+		Digest string `json:"digest"`
+		Chunks int    `json:"chunks"`
+		File   string `json:"file"`
+	}
+	if err := json.Unmarshal(got.Result, &ans); err != nil || ans.Digest != "d1" || ans.Chunks != 3 {
+		t.Fatalf("the answer %s: %v", got.Result, err)
+	}
+	if body, err := base64.StdEncoding.DecodeString(ans.File); err != nil || string(body) != string(file) {
+		t.Errorf("the file handed is %d bytes, want the %d sent: %v", len(body), len(file), err)
+	}
+}