A node is given how it hears its declarations as it enrols

The node's declaration consumer was asserted only when the control plane
started, so the first machine of a mesh, enrolling after the control
plane was up, joined and then heard nothing: its host retried 'consumer
not found' for ever (novox/hq issue 146).

internal/link/enrol_consumer_test.go

@@ -0,0 +1,51 @@
+package link
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"log"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/broker"
+)
+
+type ensured struct{ consumers []broker.Consumer }
+
+func (e *ensured) EnsureConsumer(c broker.Consumer) error {
+	e.consumers = append(e.consumers, c)
+	return nil
+}
+
+type acceptsAs string
+
+func (n acceptsAs) Enrol(context.Context, EnrolRequest) (EnrolReply, error) {
+	return EnrolReply{Accepted: true, Node: string(n)}, nil
+}
+
+type anEnrolment struct{ body []byte }
+
+func (m anEnrolment) Kind() string                         { return "enrol" }
+func (m anEnrolment) Body() []byte                         { return m.body }
+func (m anEnrolment) Redelivered() bool                    { return false }
+func (m anEnrolment) HeldFor() time.Duration               { return 0 }
+func (m anEnrolment) Answer(context.Context, []byte) error { return nil }
+func (m anEnrolment) Took() error                          { return nil }
+func (m anEnrolment) Hold(time.Duration) error             { return nil }
+func (m anEnrolment) Drop() error                          { return nil }
+
+// **A node that enrols can hear its declarations at once** (novox/hq 04-ISSUES/146): its consumer is
+// made as it enrols, not only when the control plane next starts — the first machine of a mesh
+// enrols after the control plane is up, and heard nothing.
+func TestAnEnrolledNodeIsGivenHowItHearsItsDeclarations(t *testing.T) {
+	made := &ensured{}
+	s := &Server{enroller: acceptsAs("anchor"), consumers: made, log: log.New(io.Discard, "", 0)}
+	body, _ := json.Marshal(EnrolRequest{Node: "anchor"})
+	s.enrolling(context.Background(), anEnrolment{body: body})
+
+	want := broker.NodeConsumer("anchor")
+	if len(made.consumers) != 1 || made.consumers[0].Name != want.Name || made.consumers[0].Stream != want.Stream {
+		t.Fatalf("the enrolled node was given %v, want its own declaration consumer %v", made.consumers, want)
+	}
+}