Bound external reference reads and fingerprints

internal/framework/pipeline/handoff_test.go

@@ -185,6 +185,27 @@ func TestGeneratedReferenceFingerprintChangesWithCanonicalContent(t *testing.T)
 	}
 }
 
+func TestGeneratedReferenceFingerprintChangesWithCanonicalSize(t *testing.T) {
+	input, step, producerOutput := handoffFixture(t, codecNotes{Items: []string{"first"}})
+	sets, _, err := buildStepReferenceSets(input, step, []contracts.SerializedOutput{producerOutput})
+	if err != nil {
+		t.Fatalf("build reference set: %v", err)
+	}
+	key := keyForReferenceTarget(step.lanes[0].resolved.ExtractReferences)
+	firstDeps := generatedReferenceDependencies(sets[key])
+	changed := CloneReferenceSet(sets[key])
+	item := changed.Slots["producer-output"].Items[0]
+	item.SizeBytes++
+	changed.Slots["producer-output"] = contracts.ResolvedReferenceSlot{
+		Slot:  changed.Slots["producer-output"].Slot,
+		Items: []contracts.ReferenceItem{item},
+	}
+	secondDeps := generatedReferenceDependencies(changed)
+	if reflect.DeepEqual(firstDeps, secondDeps) {
+		t.Fatalf("generated dependencies = %#v, want size-sensitive fingerprint", firstDeps)
+	}
+}
+
 func TestRunnerHandsOffAcceptedNormalizedOutputBeforeConsumerLanes(t *testing.T) {
 	input, _, _ := handoffFixture(t, codecNotes{Items: []string{"first"}})
 	prepared := input.Prepared