issue 974: review 1: a verb's end, a provisioner client's word and a failed key read each ask or retry a look; the silent bucket ages; the acceptance test starts the rollout through the serving wiring

cmd/mesh-controller/verb_looks_test.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"context"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+// A plan moved by a seat verb is looked at as the verb ends (issue 974, review 1): the verb runs as a child process
+// whose saves the serving controller does not hear, so `deliver`, which lets a walk go after the operator's approval,
+// would leave its first tier waiting for an unrelated event.
+func TestAVerbThatMayMoveAPlanHasTheServingControllerLookWhenItEnds(t *testing.T) {
+	var looks, failures atomic.Int32
+	l := lookerCounting(&failures, &looks, nil)
+	lookerMu.Lock()
+	theLooker = l
+	lookerMu.Unlock()
+	t.Cleanup(func() { lookerMu.Lock(); theLooker = nil; lookerMu.Unlock() })
+	ctx, stop := context.WithCancel(context.Background())
+	defer stop()
+	go l.run(ctx)
+
+	was := runTheVerb
+	runTheVerb = func(context.Context, []string) (verbAnswer, error) { return verbAnswer{}, nil }
+	t.Cleanup(func() { runTheVerb = was })
+	handlers, _, err := seatToolHandlers()
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, c := range []struct {
+		verb string
+		args string
+		look bool
+	}{
+		{"deliver", `{"plan":"p"}`, true},
+		{"plans", `{"stop":"plan-1","why":"w"}`, true},
+		{"plans", `{}`, false},
+		{"nodes", `{}`, false},
+	} {
+		before := looks.Load()
+		h := handlers[c.verb]
+		if h == nil {
+			t.Fatalf("no verb %s", c.verb)
+		}
+		if _, err := h(ctx, []byte(c.args)); err != nil {
+			t.Fatalf("%s %s: %v", c.verb, c.args, err)
+		}
+		time.Sleep(100 * time.Millisecond)
+		if got := looks.Load() > before; got != c.look {
+			t.Errorf("%s %s: look asked = %v; want %v", c.verb, c.args, got, c.look)
+		}
+	}
+}