Module assigner client: the placement and seat-holders states by name, and the machines a placement names (ADR 0634 §4; issue 1966)

Claude-Session: https://claude.ai/code/session_01NcbgfFSnn24M3GcqttoU7i

placement/go/clients/meshmoduleassignerclient/reads.go

@@ -0,0 +1,37 @@
+package meshmoduleassignerclient
+
+import (
+	"sort"
+
+	seat "git.novox.be/novox/mesh-contracts/placement/go/seats/meshmoduleassigner"
+)
+
+// The holder of the seat and the names a reader of its states declares in its `reads` (`<module>.<state>`) and binds
+// to (`<module>_<state>`): named here once, by the seat's state, so no reader builds them from a module's name
+// (ADR 0634 §4; the lead's ruling of 2026-11-05).
+const (
+	// Module is the module that holds the seat mesh-module-assigner.
+	Module = "mesh-delivery-assigner"
+	// PlacementRead and SeatHoldersRead are the states `placement` and `seat-holders`, as a manifest's `reads` names them.
+	PlacementRead   = Module + "." + seat.StatePlacement
+	SeatHoldersRead = Module + "." + seat.StateSeatHolders
+	// PlacementBucket and SeatHoldersBucket are the states' buckets.
+	PlacementBucket   = Module + "_" + seat.StatePlacement
+	SeatHoldersBucket = Module + "_" + seat.StateSeatHolders
+)
+
+// MachineNames is every machine the seat places modules on, sorted, from its state `placement` as a reader holds its
+// keys: each with a node key `<node>.node` or, in the form before, `placement.<node>`. Module keys and keys of the
+// state's other kinds are passed over.
+func MachineNames(keys map[string][]byte) []string {
+	seen := map[string]bool{}
+	out := []string{}
+	for k := range keys {
+		if node, _, kind, err := ParseKey(k); err == nil && kind != ModuleKind && !seen[node] {
+			seen[node] = true
+			out = append(out, node)
+		}
+	}
+	sort.Strings(out)
+	return out
+}

placement/go/clients/meshmoduleassignerclient/reads_test.go

@@ -0,0 +1,22 @@
+package meshmoduleassignerclient
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestTheStatesAreNamedBySeatAndState(t *testing.T) {
+	for got, want := range map[string]string{PlacementRead: "mesh-delivery-assigner.placement", SeatHoldersRead: "mesh-delivery-assigner.seat-holders",
+		PlacementBucket: "mesh-delivery-assigner_placement", SeatHoldersBucket: "mesh-delivery-assigner_seat-holders"} {
+		if got != want {
+			t.Errorf("got %q, want %q", got, want)
+		}
+	}
+}
+
+func TestMachineNamesAreTheNodesAKeyNames(t *testing.T) {
+	keys := map[string][]byte{"g14.node": nil, "g14.app": nil, "ace.node": nil, "placement.novox": nil, "want.x.y": nil, "bad": nil}
+	if got, want := MachineNames(keys), []string{"ace", "g14", "novox"}; !reflect.DeepEqual(got, want) {
+		t.Errorf("MachineNames = %v, want %v", got, want)
+	}
+}