Judge a leaf module on one healthy reading, a core module on three (hq issue 524)

ADR 0282 decided readings by class and ADR 0304 took a leaf module to
one, but the gate never learned it: every build, leaf or core, needed
three readings over at least two minutes, so a container module that
was healthy at once still waited about two and a half minutes on its
first machine. The number of readings and the settle time now follow
the module's class: three after two minutes for the controller's own
path and the resolver, one for every other module. Tests that judge a
gate's other rules keep leaf modules on three readings.

cmd/mesh-controller/gate_test.go

@@ -153,6 +153,7 @@ func (g *gateMesh) plan(t *testing.T) inventory.Plan {
 // registered and sent to it again — and never reaches the second machine; it is marked, said as a
 // condition and an event, never registered or rolled back again.
 func TestABuildThatFailsItsGateIsRolledBackOnItsFirstMachineAndGoesNoFurther(t *testing.T) {
+	judgeLeavesAsTheCore(t)
 	g := aGateMesh(t)
 	ctx := t.Context()
 	inv := g.open.inventory
@@ -255,7 +256,7 @@ func TestABuildThatPassesItsGateRollsEverywhereUnattended(t *testing.T) {
 		t.Fatalf("sent %v", g.sent)
 	}
 	gate := p.Modules["app"].Gate
-	if p.State != inventory.PlanDone || gate == nil || gate.Verdict != inventory.GatePassed || gate.Passes < gatePasses {
+	if p.State != inventory.PlanDone || gate == nil || gate.Verdict != inventory.GatePassed || gate.Passes < gateWanted(gate) {
 		t.Fatalf("the plan is %s (%s), its gate %+v", p.State, p.Note, gate)
 	}
 	if v, found, err := g.open.inventory.GateOf(ctx, "build-2"); err != nil || !found || v.Verdict != inventory.GatePassed {
@@ -266,8 +267,51 @@ func TestABuildThatPassesItsGateRollsEverywhereUnattended(t *testing.T) {
 	}
 }
 
+// A leaf module passes its gate on one reading, as soon as its first machine is healthy, without waiting out the
+// core's settle time (novox/hq ADR 0282 decision 4 as ADR 0304 decision 3 changed it, issue 524).
+func TestALeafModulePassesOnOneHealthyReading(t *testing.T) {
+	g := aGateMesh(t)
+	ctx := t.Context()
+	gateSettle = time.Hour    // a core module could not pass for an hour
+	advancePlans(ctx, g.open) // the first machine is sent the new build
+	advancePlans(ctx, g.open) // one healthy judging
+	p := g.plan(t)
+	gate := p.Modules["app"].Gate
+	if gate == nil || gate.Verdict != inventory.GatePassed || gate.Passes != 1 || gate.Wants != 1 {
+		t.Fatalf("a leaf module's gate after one healthy judging: %+v (plan %s: %s)", gate, p.State, p.Note)
+	}
+	if !strings.Contains(gate.Why, "healthy 1 times") {
+		t.Errorf("the verdict says %q", gate.Why)
+	}
+}
+
+// Which modules are judged as the core: those on the controller's own path and the resolver's holder, three
+// readings after the settle time; every other module one (novox/hq ADR 0282 decision 1, ADR 0304 decision 3).
+func TestAModuleIsJudgedByItsClass(t *testing.T) {
+	for _, c := range []struct {
+		module  string
+		claims  []catalogue.Claim
+		passes  int
+		settles bool
+	}{
+		{"app", nil, 1, false},
+		{"nzbget", nil, 1, false},
+		{"mesh-controller", nil, 3, true},
+		{"mesh-host", nil, 3, true},
+		{"node-tools", nil, 3, true},
+		{"nats", nil, 3, true},
+		{"dnsmasq", []catalogue.Claim{{Name: resolverSeat}}, 3, true},
+	} {
+		p, s := gateWants(c.module, catalogue.Manifest{Module: c.module, Claims: c.claims})
+		if p != c.passes || s != c.settles {
+			t.Errorf("%s: %d passes, settles %v; want %d, %v", c.module, p, s, c.passes, c.settles)
+		}
+	}
+}
+
 // A first machine that never becomes healthy fails its gate at the bound, and is put back.
 func TestABuildNeverHealthyFailsAtTheBound(t *testing.T) {
+	judgeLeavesAsTheCore(t)
 	g := aGateMesh(t)
 	ctx := t.Context()
 	advancePlans(ctx, g.open)
@@ -593,3 +637,13 @@ func TestAWitnessesVerdictIsAConditionWhileItsReportsSayIt(t *testing.T) {
 		t.Fatalf("a verdict the reports no longer carry is still said: %+v %v", obs, err)
 	}
 }
+
+// judgeLeavesAsTheCore makes a test's leaf modules judged as a core module is, three readings after the settle
+// time, for a test of the gate's other rules (a fault, the bound, a supersession) that needs a judging still
+// open after a healthy reading.
+func judgeLeavesAsTheCore(t *testing.T) {
+	t.Helper()
+	wasPasses, wasSettles := gateLeafPasses, gateLeafSettles
+	gateLeafPasses, gateLeafSettles = gatePasses, true
+	t.Cleanup(func() { gateLeafPasses, gateLeafSettles = wasPasses, wasSettles })
+}