mesh-grants: grants_accounts reads the account consumers' differences in shadow, where no condition is raised (issue 774, ADR 0561 §6, §9)

modules/mesh-grants/cmd/mesh-grants/tools.go

@@ -120,8 +120,10 @@ func toolsOf(p *grants.Part) []stdio.Tool {
 		{Name: grants.ToolAccounts, Description: "The bus accounts the mesh wants (novox/hq ADR 0561 §2, §9): every account the vault " +
 			"mints that placement composes (a module's, a process's, a machine's provisioner client's), as the grants part last " +
 			"wrote it to its state accounts, which the vault alone reads: user, kind, node, module, process, the bus's address and " +
-			"fingerprint, a module's claims with the verbs each seat promises, and when the key was written; one user's or all; and " +
-			"what the last pass wrote, deleted or kept. Never a password. Read-only: grants_compose_now writes them again.",
+			"fingerprint, a module's claims with the verbs each seat promises, and when the key was written; one user's or all; " +
+			"what the last pass wrote, deleted or kept; and the durable consumers the accounts need as the last pass found them " +
+			"(missing, differing and why, created; whether the lease is handed away). Never a password. Read-only: " +
+			"grants_compose_now writes them again.",
 			Input: schema(map[string]string{"user": "one bus user, e.g. ace.mesh-build-go"}),
 			Run:   func(a map[string]any) (any, error) { return p.Accounts(grants.Answer(a, "user")) }},
 		{Name: grants.ToolConsumerMatch, Description: "Bring one durable consumer an account needs (a module's on EVENTS, a process's on " +

modules/mesh-grants/grants_test.go

@@ -1771,6 +1771,10 @@ func TestGrants(t *testing.T) {
 		if _, err := p.Accounts("b.mod-y"); err == nil {
 			t.Error("the tool reads an account no longer wanted")
 		}
+		p.Pass()
+		if all, _ := p.Accounts(""); all.(map[string]any)["consumers"] == nil {
+			t.Errorf("the tool does not say the account consumers in shadow: %v", all)
+		}
 		// With no bus address no account is written, and the pass says why.
 		bare := partOn(fixture())
 		if res := bare.Compose(); res.Accounts != nil || !strings.Contains(strings.Join(res.Errors, " "), "no bus address") {

modules/mesh-grants/internal/grants/accounts.go

@@ -138,6 +138,11 @@ func (p *Part) Accounts(user string) (any, error) {
 		if json.Unmarshal(raw, &res) == nil && res.Accounts != nil {
 			answer["last_pass"] = res.Accounts
 		}
+		// And the durable consumers the accounts need, as the last pass found them: missing and differing ones are read
+		// here in shadow too, where no condition is raised (ADR 0561 §6, §9).
+		if res.Consumers != nil {
+			answer["consumers"] = res.Consumers
+		}
 	}
 	return answer, nil
 }