Check a ledger operation against the types its binding carries, refusing a ledger bound with none (issue 1966 T2)

node-tools/internal/runtime/ledgers.go

@@ -20,21 +20,9 @@ import (
 // for the module whose bundle or whose repair tool asks, from its own bindings alone, with its types and the connection
 // its history is published on.
 
-// LedgerTypes is where the runner reads a ledger's types, by module and local name. Where it reads them from on the
-// live mesh is not decided (issue 1966: the binding carries no types, and no record names a source); until it is,
-// the runner refuses to open a ledger and says why, and a test gives the types.
-type LedgerTypes func(module, local string) ([]catalogue.LedgerType, error)
-
-// errTypesUndecided is the refusal of a ledger whose types the runner has no source for.
-func errTypesUndecided(module, local string) error {
-	return fmt.Errorf("the tool runner cannot open %s's ledger %q: it reads a ledger's types from nowhere yet, since its "+
-		"binding carries none and no record names their source (issue 1966)", module, local)
-}
-
-// ledgerSource is how the runner opens a module's ledger: its types, and the connection its history and snapshots are
-// published on (the module's ledger credential, ADR 0597 §9).
+// ledgerSource is how the runner opens a module's ledger beside its binding: the connection its history and snapshots
+// are published on (the module's ledger credential, ADR 0597 §9).
 type ledgerSource struct {
-	types  LedgerTypes
 	writer func(module string) (*bus.Conn, error)
 }
 
@@ -97,13 +85,12 @@ func (c *consumers) ledger(module, local string) (*ledger.Ledger, error) {
 	if err != nil {
 		return nil, err
 	}
-	types := c.ledgers.types
-	if types == nil {
-		return nil, errTypesUndecided(module, local)
-	}
-	ts, err := types(module, local)
-	if err != nil {
-		return nil, err
+	// Its types travel on its binding, copied by the grants part from the entry the manifest-accepted event carries
+	// (mesh-sdk membership.BusBinding.Types): the runner reads no other part's state for them (ADR 0596).
+	ts := b.Types
+	if len(ts) == 0 {
+		return nil, fmt.Errorf("%s's ledger %q is bound with no types, so no operation can be checked against one: its "+
+			"binding carries the types its manifest asks for in `requires` (novox/hq ADR 0597 §1)", module, local)
 	}
 	var writer *bus.Conn
 	if c.ledgers.writer != nil {