Require configuration selectors only for applicable scopes

config_test.go

@@ -217,3 +217,41 @@ func TestConfigPreflightRejectsUnsupportedAggregateAndInapplicableSelector(t *te
 func noopConfigAcquire[C any](context.Context, ConfigRequest, C) (Acquired[ConfigView], error) {
 	return Acquired[ConfigView]{}, nil
 }
+
+func TestRequiredConfigSelectorOnlyAppliesToSelectedScopes(t *testing.T) {
+	app, _ := New(Identity{Name: "example"})
+	calls := 0
+	acquire := func(context.Context, ConfigRequest, string) (Acquired[ConfigView], error) {
+		calls++
+		return Acquired[ConfigView]{}, nil
+	}
+	err := RegisterConfig(app, ConfigSuite[string]{
+		Selectors: []Selector[string]{{Scopes: []string{"app"}, Binding: ValueFlag[string](FlagMeta{Name: "campaign", Required: true}, nil, parseString, func(c *string, v Supplied[string]) { *c = v.Value })}},
+		Scopes:    []ConfigScope[string]{{Name: "app", Operations: []ConfigOperation{ConfigValidate}, Acquire: acquire}, {Name: "promptkit", Operations: []ConfigOperation{ConfigValidate}, Acquire: acquire}},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, tc := range []struct {
+		args  []string
+		kind  OutcomeKind
+		calls int
+	}{
+		{[]string{"--scope", "promptkit"}, OutcomeSuccess, 1},
+		{nil, OutcomeUsage, 0},
+		{[]string{"--scope", "all"}, OutcomeUsage, 0},
+		{[]string{"--scope", "all", "--campaign", "spring"}, OutcomeSuccess, 2},
+		{[]string{"--scope", "promptkit", "--campaign", "spring"}, OutcomeUsage, 0},
+		{[]string{"--help"}, OutcomeSuccess, 0},
+	} {
+		calls = 0
+		var out bytes.Buffer
+		result := app.Execute(context.Background(), append([]string{"config", "validate"}, tc.args...), Streams{Out: &out})
+		if result.Kind != tc.kind || calls != tc.calls {
+			t.Fatalf("%v: result=%#v calls=%d", tc.args, result, calls)
+		}
+		if len(tc.args) > 0 && tc.args[0] == "--help" && !strings.Contains(out.String(), "required where applicable") {
+			t.Fatalf("help=%q", out.String())
+		}
+	}
+}