A module may invoke tools, and a manifest is checked where it is written

invokes: a manifest word that becomes exactly the publish grant a person's account gets (ADR 0152),
derived by the same composition; refused at parse when it names no tool. module check <file|dir>...
runs what registration runs with no store, for a manifest in any repository (hq issue 148).

internal/broker/invokes_test.go

@@ -0,0 +1,92 @@
+package broker
+
+import (
+	"strings"
+	"testing"
+)
+
+// A module that says it calls a tool may publish exactly that subject (novox/hq ADR 0152): the same
+// grant a person gets, derived the same way, so one list answers "what may this ask" for everybody.
+func TestAModuleMayAskOnlyTheToolsItInvokes(t *testing.T) {
+	perms, err := PermissionsFor(Principal{Kind: KindModule, Node: "desk", Module: "mesh-console",
+		Invokes: []string{"shop.price"}, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	has(t, perms.Publish, "mesh.mod.shop.tool.price")
+	hasNot(t, perms.Publish, "mesh.mod.shop.tool.refund")
+	hasNot(t, perms.Publish, "mesh.mod.*.tool.>")
+}
+
+// The console's grant: every tool, as one subject, and it reads as one.
+func TestAModuleInvokingEverythingMayAskAnyTool(t *testing.T) {
+	perms, err := PermissionsFor(Principal{Kind: KindModule, Node: "desk", Module: "mesh-console",
+		Invokes: []string{"*"}, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	has(t, perms.Publish, "mesh.mod.*.tool.>")
+}
+
+// **A grant to call widens nothing else.** A module that invokes may not publish an event it did not
+// declare, may not answer as another module, and subscribes nothing it did not consume — the
+// difference between the console and a person is that the console is on a machine, not that it may
+// do more.
+func TestInvokingGrantsNothingButTheCall(t *testing.T) {
+	perms, err := PermissionsFor(Principal{Kind: KindModule, Node: "desk", Module: "mesh-console",
+		Invokes: []string{"*"}, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, p := range perms.Publish {
+		if strings.Contains(p, ".event.") {
+			t.Errorf("a module that only invokes may publish %q, an event it never declared", p)
+		}
+		if strings.HasPrefix(p, "mesh.seat.") {
+			t.Errorf("a module that only invokes may publish %q, a seat it neither holds nor uses", p)
+		}
+	}
+	for _, s := range perms.Subscribe {
+		if strings.Contains(s, ".tool.") && !strings.HasPrefix(s, "mesh.mod.mesh-console.") {
+			t.Errorf("a module that invokes may subscribe %q, another module's tools", s)
+		}
+	}
+}
+
+// A module that declares no invokes calls nothing, which is every module but the console.
+func TestAModuleThatInvokesNothingCallsNothing(t *testing.T) {
+	perms, err := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "shop",
+		Emits: []string{"order.placed"}, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, p := range perms.Publish {
+		if strings.Contains(p, ".tool.") {
+			t.Errorf("a module with no invokes may publish %q", p)
+		}
+	}
+}
+
+// The malformed entry is refused for a module as it is for a person, and in the same words.
+func TestAModulesToolGrantThatNamesNoToolIsRefused(t *testing.T) {
+	if _, err := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "shop",
+		Invokes: []string{"telegram"}, PasswordHash: "x"}); err == nil {
+		t.Fatal("a grant naming a module but no tool was accepted")
+	}
+}
+
+// What a declaration says reaches the composed user, so a manifest's `invokes` is the grant.
+func TestADeclaredInvokeReachesTheComposedUser(t *testing.T) {
+	users, err := Users(Records{
+		Nodes:    []string{"desk"},
+		Assigned: map[string][]Declared{"desk": {{Module: "mesh-console", Invokes: []string{"*"}}}},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	perms, err := PermissionsFor(users[len(users)-1])
+	if err != nil {
+		t.Fatal(err)
+	}
+	has(t, perms.Publish, "mesh.mod.*.tool.>")
+}