test(01-02): add failing test for optional plugin services

- Cover typed Publish/Lookup, duplicate providers and HasPlugin
- Require missing/cycle errors to name plugin IDs before Boot
- Assert greeter works with and without an optional extra

party/registry_test.go

@@ -76,6 +76,128 @@ func TestActivateMergesHasConfigBeforeRegister(t *testing.T) {
 	}
 }
 
+func TestActivateMissingRequiresNamesIDsAndSkipsBoot(t *testing.T) {
+	var log []string
+	p := &tracePlugin{id: "golem15.greeter", req: []string{"golem15.hello"}, log: &log}
+	app := backpack.New(&compass.Config{})
+	_, err := activate([]Plugin{p}, app, []string{"golem15.greeter"})
+	if err == nil {
+		t.Fatal("expected missing dependency error")
+	}
+	msg := err.Error()
+	if !strings.Contains(msg, "golem15.greeter") || !strings.Contains(msg, "golem15.hello") {
+		t.Fatalf("error %q should name both plugin IDs", msg)
+	}
+	if strings.Contains(strings.Join(log, ","), "boot") {
+		t.Fatalf("Boot ran despite missing dependency: %v", log)
+	}
+}
+
+func TestActivateCycleNamesIDsAndSkipsBoot(t *testing.T) {
+	var log []string
+	a := &tracePlugin{id: "golem15.a", req: []string{"golem15.b"}, log: &log}
+	b := &tracePlugin{id: "golem15.b", req: []string{"golem15.a"}, log: &log}
+	app := backpack.New(&compass.Config{})
+	_, err := activate([]Plugin{a, b}, app, []string{"golem15.a", "golem15.b"})
+	if err == nil {
+		t.Fatal("expected cycle error")
+	}
+	msg := err.Error()
+	if !strings.Contains(msg, "golem15.a") || !strings.Contains(msg, "golem15.b") {
+		t.Fatalf("error %q should name cycle members", msg)
+	}
+	if strings.Contains(strings.Join(log, ","), "boot") || strings.Contains(strings.Join(log, ","), "register") {
+		t.Fatalf("lifecycle ran despite cycle: %v", log)
+	}
+}
+
+func TestActivateDuplicateIDRejected(t *testing.T) {
+	var log []string
+	a := &tracePlugin{id: "golem15.hello", log: &log}
+	dup := &tracePlugin{id: "golem15.hello", log: &log}
+	app := backpack.New(&compass.Config{})
+	_, err := activate([]Plugin{a, dup}, app, []string{"golem15.hello"})
+	if err == nil {
+		t.Fatal("expected duplicate id error")
+	}
+	if !strings.Contains(err.Error(), "golem15.hello") {
+		t.Fatalf("error %q should name the duplicate id", err)
+	}
+}
+
+type bootProbe struct {
+	id      string
+	req     []string
+	log     *[]string
+	sawOpt  *bool
+	booted  *[]string
+}
+
+func (p *bootProbe) ID() string         { return p.id }
+func (p *bootProbe) Requires() []string { return p.req }
+
+func (p *bootProbe) Register(*backpack.App) error {
+	*p.log = append(*p.log, p.id+":register")
+	return nil
+}
+
+func (p *bootProbe) Boot(app *backpack.App) error {
+	if p.sawOpt != nil && p.id == "golem15.hello" {
+		*p.sawOpt = app.HasPlugin("golem15.optional")
+	}
+	*p.log = append(*p.log, p.id+":boot")
+	if p.booted != nil {
+		*p.booted = append(*p.booted, p.id)
+	}
+	return nil
+}
+
+func TestActivateHasPluginSeesNotYetBootedPlugins(t *testing.T) {
+	var log []string
+	var saw bool
+	hello := &bootProbe{id: "golem15.hello", log: &log, sawOpt: &saw}
+	opt := &bootProbe{id: "golem15.optional", log: &log}
+	app := backpack.New(&compass.Config{})
+	if _, err := activate([]Plugin{opt, hello}, app, []string{"golem15.hello", "golem15.optional"}); err != nil {
+		t.Fatalf("activate: %v", err)
+	}
+	if !saw {
+		t.Fatal("HasPlugin(golem15.optional) was false during hello Boot; complete set must be visible before Boot")
+	}
+	want := []string{
+		"golem15.hello:register",
+		"golem15.optional:register",
+		"golem15.hello:boot",
+		"golem15.optional:boot",
+	}
+	if strings.Join(log, ",") != strings.Join(want, ",") {
+		t.Fatalf("lifecycle = %v, want %v", log, want)
+	}
+}
+
+func TestActivateIndependentPluginsKeepManifestOrder(t *testing.T) {
+	var log []string
+	a := &tracePlugin{id: "golem15.a", log: &log}
+	b := &tracePlugin{id: "golem15.b", log: &log}
+	c := &tracePlugin{id: "golem15.c", log: &log}
+	app := backpack.New(&compass.Config{})
+	got, err := activate([]Plugin{c, a, b}, app, []string{"golem15.c", "golem15.a", "golem15.b"})
+	if err != nil {
+		t.Fatalf("activate: %v", err)
+	}
+	if len(got) != 3 || got[0].ID() != "golem15.c" || got[1].ID() != "golem15.a" || got[2].ID() != "golem15.b" {
+		t.Fatalf("order = %v", idsOf(got))
+	}
+}
+
+func idsOf(plugins []Plugin) []string {
+	out := make([]string, len(plugins))
+	for i, p := range plugins {
+		out[i] = p.ID()
+	}
+	return out
+}
+
 func TestActivateRunsAllRegisterBeforeAnyBoot(t *testing.T) {
 	var log []string
 	hello := &tracePlugin{id: "golem15.hello", log: &log}