refactor(node): stronger types for account paths

packages/app-node/src/backend/accounting/computed/total-owner-balance.ts

@@ -1,24 +1,30 @@
 import { Reactor, createComputed } from "@dassie/lib-reactive"
 
+import { OwnerLedgerIdSignal } from "../signals/owner-ledger-id"
 import { LedgerStore } from "../stores/ledger"
 import { PostedTransfersTopic } from "../topics/posted-transfers"
 
 export const TotalOwnerBalanceSignal = (reactor: Reactor) =>
   createComputed(reactor, () => {
     const ledger = reactor.use(LedgerStore)
+    const ownerLedgerIdSignal = reactor.use(OwnerLedgerIdSignal)
 
     let balance = 0n
-    for (const account of ledger.getAccounts("builtin/owner/")) {
+    for (const account of ledger.getAccounts(
+      `${ownerLedgerIdSignal.read()}:owner/`,
+    )) {
       balance += account.creditsPosted - account.debitsPosted
     }
 
     reactor.use(PostedTransfersTopic).on(reactor, (transfer) => {
+      const ownerAccountPrefix = `${ownerLedgerIdSignal.read()}:owner/`
+
       let newBalance = balance
-      if (transfer.creditAccount.startsWith("builtin/owner/")) {
+      if (transfer.creditAccount.startsWith(ownerAccountPrefix)) {
         newBalance += transfer.amount
       }
 
-      if (transfer.debitAccount.startsWith("builtin/owner/")) {
+      if (transfer.debitAccount.startsWith(ownerAccountPrefix)) {
         newBalance -= transfer.amount
       }
 

packages/app-node/src/backend/accounting/functions/apply-interledger-packet.ts

@@ -1,16 +1,17 @@
 import { CreateTransferParameters } from "../stores/ledger"
+import { AccountPath, ConnectorAccount } from "../types/accounts"
 import { getLedgerIdFromPath } from "./get-ledger-id-from-path"
 
 export const applyPacketPrepareToLedger = (
-  sourceAccountPath: string,
-  destinationAccountPath: string,
+  sourceAccountPath: AccountPath,
+  destinationAccountPath: AccountPath,
   amount: bigint,
 ) => {
   const transfers = []
 
   {
     const ledgerId = getLedgerIdFromPath(sourceAccountPath)
-    const connectorPath = `${ledgerId}/internal/connector`
+    const connectorPath: ConnectorAccount = `${ledgerId}:internal/connector`
 
     const transfer: CreateTransferParameters = {
       debitAccountPath: sourceAccountPath,
@@ -23,7 +24,7 @@ export const applyPacketPrepareToLedger = (
   }
   {
     const ledgerId = getLedgerIdFromPath(destinationAccountPath)
-    const connectorPath = `${ledgerId}/internal/connector`
+    const connectorPath: ConnectorAccount = `${ledgerId}:internal/connector`
 
     const transfer: CreateTransferParameters = {
       debitAccountPath: connectorPath,

packages/app-node/src/backend/accounting/functions/get-ledger-id-from-path.ts

@@ -1,9 +1,12 @@
 import assert from "node:assert"
 
-export const getLedgerIdFromPath = (path: string) => {
-  const firstSlash = path.indexOf("/")
+import { AccountPath } from "../types/accounts"
+import { LedgerId } from "../types/ledger-id"
 
-  assert(firstSlash !== -1, "account paths must contain at least one slash")
+export const getLedgerIdFromPath = (path: AccountPath): LedgerId => {
+  const colonPosition = path.indexOf(":")
 
-  return path.slice(0, firstSlash)
+  assert(colonPosition !== -1, "account paths must contain a colon")
+
+  return path.slice(0, colonPosition) as LedgerId
 }

packages/app-node/src/backend/accounting/functions/manage-common-accounts.ts

@@ -1,9 +1,9 @@
-import { SettlementSchemeId } from "../../peer-protocol/types/settlement-scheme-id"
 import { Ledger } from "../stores/ledger"
+import { LedgerId } from "../types/ledger-id"
 
 export const initializeCommonAccounts = (
   ledger: Ledger,
-  settlementSchemeId: SettlementSchemeId,
+  ledgerId: LedgerId,
 ) => {
-  ledger.createAccount(`${settlementSchemeId}/internal/connector`)
+  ledger.createAccount(`${ledgerId}:internal/connector`)
 }

packages/app-node/src/backend/accounting/functions/manage-peer.ts

@@ -3,28 +3,28 @@ import assert from "node:assert"
 import { isFailure } from "@dassie/lib-type-utils"
 
 import { NodeId } from "../../peer-protocol/types/node-id"
-import { SettlementSchemeId } from "../../peer-protocol/types/settlement-scheme-id"
 import { Ledger } from "../stores/ledger"
+import { LedgerId } from "../types/ledger-id"
 
 const DEFAULT_CREDIT = 1_100_000_000n
 
 export const initializePeer = (
   ledger: Ledger,
-  settlementSchemeId: SettlementSchemeId,
+  ledgerId: LedgerId,
   peerId: NodeId,
 ) => {
-  ledger.createAccount(`${settlementSchemeId}/peer/${peerId}/interledger`, {
+  ledger.createAccount(`${ledgerId}:peer/${peerId}/interledger`, {
     limit: "debits_must_not_exceed_credits",
   })
-  ledger.createAccount(`${settlementSchemeId}/peer/${peerId}/settlement`)
-  ledger.createAccount(`${settlementSchemeId}/peer/${peerId}/trust`, {
+  ledger.createAccount(`${ledgerId}:peer/${peerId}/settlement`)
+  ledger.createAccount(`${ledgerId}:peer/${peerId}/trust`, {
     limit: "credits_must_not_exceed_debits",
   })
 
   // Extend initial trust limit
   const result = ledger.createTransfer({
-    debitAccountPath: `${settlementSchemeId}/peer/${peerId}/trust`,
-    creditAccountPath: `${settlementSchemeId}/peer/${peerId}/interledger`,
+    debitAccountPath: `${ledgerId}:peer/${peerId}/trust`,
+    creditAccountPath: `${ledgerId}:peer/${peerId}/interledger`,
     amount: DEFAULT_CREDIT,
   })
 

packages/app-node/src/backend/accounting/functions/process-settlement.ts

@@ -1,15 +1,20 @@
 import { NodeId } from "../../peer-protocol/types/node-id"
 import { CreateTransferParameters, Ledger } from "../stores/ledger"
+import {
+  PeerInterledgerAccount,
+  PeerSettlementAccount,
+} from "../types/accounts"
+import { LedgerId } from "../types/ledger-id"
 
 export const processSettlementPrepare = (
   ledger: Ledger,
-  settlementSchemeId: string,
+  ledgerId: LedgerId,
   peerId: NodeId,
   amount: bigint,
   direction: "incoming" | "outgoing",
 ) => {
-  const peerPath = `${settlementSchemeId}/peer/${peerId}/interledger`
-  const settlementPath = `${settlementSchemeId}/peer/${peerId}/settlement`
+  const peerPath: PeerInterledgerAccount = `${ledgerId}:peer/${peerId}/interledger`
+  const settlementPath: PeerSettlementAccount = `${ledgerId}:peer/${peerId}/settlement`
 
   const transfer: CreateTransferParameters = {
     debitAccountPath: direction === "incoming" ? settlementPath : peerPath,

packages/app-node/src/backend/accounting/manage-builtin-accounts.ts

@@ -1,15 +1,16 @@
 import { createActor } from "@dassie/lib-reactive"
 
-import { SettlementSchemeId } from "../peer-protocol/types/settlement-scheme-id"
 import { initializeCommonAccounts } from "./functions/manage-common-accounts"
+import { OwnerLedgerIdSignal } from "./signals/owner-ledger-id"
 import { LedgerStore } from "./stores/ledger"
 
 export const ManageBuiltinAccountsActor = () =>
   createActor((sig) => {
     const ledger = sig.reactor.use(LedgerStore)
+    const ledgerId = sig.read(OwnerLedgerIdSignal)
 
-    initializeCommonAccounts(ledger, "builtin" as SettlementSchemeId)
-    ledger.createAccount(`builtin/owner/spsp`)
-    ledger.createAccount(`builtin/owner/btp`)
-    ledger.createAccount(`builtin/owner/http`)
+    initializeCommonAccounts(ledger, ledgerId)
+    ledger.createAccount(`${ledgerId}:owner/spsp`)
+    ledger.createAccount(`${ledgerId}:owner/btp`)
+    ledger.createAccount(`${ledgerId}:owner/http`)
   })

packages/app-node/src/backend/accounting/signals/owner-ledger-id.ts

@@ -0,0 +1,16 @@
+import { createSignal } from "@dassie/lib-reactive"
+
+import { LedgerId } from "../types/ledger-id"
+
+/**
+ * Determines which internal ledger the owner accounts are on.
+ *
+ * @remarks
+ *
+ * Dassie aims for multi-currency support but in this current version, the owner accounts are only on one ledger. This
+ * signal determines which ledger that is.
+ *
+ * Owner accounts are the accounts that are used when the node's owner sends or receives money or connects a client via
+ * BTP etc.
+ */
+export const OwnerLedgerIdSignal = () => createSignal("stub" as LedgerId)

packages/app-node/src/backend/accounting/stores/ledger.ts

@@ -11,21 +11,7 @@ import { EXCEEDS_DEBITS_FAILURE } from "../failures/exceeds-debits"
 import InvalidAccountFailure from "../failures/invalid-account"
 import { getLedgerIdFromPath } from "../functions/get-ledger-id-from-path"
 import { PostedTransfersTopic } from "../topics/posted-transfers"
-
-// Ledger Account Structure
-// ------------------------
-//
-// internal/… -> Own accounts
-// internal/connector -> Connector account
-// peer/… -> Peer accounts
-// peer/<nodeId> -> Accounts for a specific peer
-// peer/<nodeId>/interledger -> Interledger packets
-// peer/<nodeId>/settlement -> Underlying settlement account
-// peer/<nodeId>/trust -> Trust extended or revoked
-// owner/… -> Owner accounts
-// owner/spsp/<spspAccountId> -> SPSP accounts
-// owner/btp/<btpAccountId> -> BTP accounts
-// owner/http/<httpAccountId> -> ILP-HTTP accounts
+import { AccountPath } from "../types/accounts"
 
 export interface LedgerAccount {
   path: string
@@ -41,14 +27,14 @@ export interface LedgerAccount {
 
 export interface Transfer {
   state: "pending" | "posted" | "voided"
-  debitAccount: string
-  creditAccount: string
+  debitAccount: AccountPath
+  creditAccount: AccountPath
   amount: bigint
 }
 
 export interface CreateTransferParameters {
-  debitAccountPath: string
-  creditAccountPath: string
+  debitAccountPath: AccountPath
+  creditAccountPath: AccountPath
   amount: bigint
   pending?: boolean
 }
@@ -61,7 +47,7 @@ export const LedgerStore = (reactor: Reactor) => {
 
   return {
     createAccount: (
-      path: string,
+      path: AccountPath,
       options: Simplify<
         Pick<SetOptional<LedgerAccount, keyof LedgerAccount>, "limit">
       > = {},
@@ -82,7 +68,7 @@ export const LedgerStore = (reactor: Reactor) => {
       ledger.set(path, account)
     },
 
-    getAccount: (path: string) => ledger.get(path),
+    getAccount: (path: AccountPath) => ledger.get(path),
 
     getAccounts: (filterPrefix: string) => ledger.filterPrefix(filterPrefix),
 

packages/app-node/src/backend/accounting/types/accounts.ts

@@ -0,0 +1,36 @@
+import { NodeId } from "../../peer-protocol/types/node-id"
+import { LedgerId } from "./ledger-id"
+
+// Ledger Account Structure
+// ------------------------
+//
+// internal/… -> Own accounts
+// internal/connector -> Connector account
+// peer/… -> Peer accounts
+// peer/<nodeId> -> Accounts for a specific peer
+// peer/<nodeId>/interledger -> Interledger packets
+// peer/<nodeId>/settlement -> Underlying settlement account
+// peer/<nodeId>/trust -> Trust extended or revoked
+// owner/… -> Owner accounts
+// owner/spsp/<spspAccountId> -> SPSP accounts
+// owner/btp/<btpAccountId> -> BTP accounts
+// owner/http/<httpAccountId> -> ILP-HTTP accounts
+
+export type ConnectorAccount = `${LedgerId}:internal/connector`
+
+export type PeerInterledgerAccount = `${LedgerId}:peer/${NodeId}/interledger`
+export type PeerSettlementAccount = `${LedgerId}:peer/${NodeId}/settlement`
+export type PeerTrustAccount = `${LedgerId}:peer/${NodeId}/trust`
+
+export type OwnerSpspAccount = `${LedgerId}:owner/spsp`
+export type OwnerBtpAccount = `${LedgerId}:owner/btp`
+export type OwnerHttpAccount = `${LedgerId}:owner/http`
+
+export type AccountPath =
+  | ConnectorAccount
+  | PeerInterledgerAccount
+  | PeerSettlementAccount
+  | PeerTrustAccount
+  | OwnerSpspAccount
+  | OwnerBtpAccount
+  | OwnerHttpAccount

packages/app-node/src/backend/accounting/types/ledger-id.ts

@@ -0,0 +1,3 @@
+import { Opaque } from "type-fest"
+
+export type LedgerId = Opaque<string, "LedgerId">

packages/app-node/src/backend/btp-server/register-btp-http-upgrade.ts

@@ -12,6 +12,7 @@ import {
 import { Reactor, createActor } from "@dassie/lib-reactive"
 import { isFailure } from "@dassie/lib-type-utils"
 
+import { OwnerLedgerIdSignal } from "../accounting/signals/owner-ledger-id"
 import { BtpTokensStore } from "../api-keys/database-stores/btp-tokens"
 import { BtpToken } from "../api-keys/types/btp-token"
 import { WebsocketRoutesSignal } from "../http-server/serve-https"
@@ -27,6 +28,7 @@ export const RegisterBtpHttpUpgradeActor = (reactor: Reactor) => {
   const processIncomingPacketActor = reactor.use(ProcessPacketActor)
   const btpTokensStore = reactor.use(BtpTokensStore)
   const routingTableSignal = reactor.use(RoutingTableSignal)
+  const ownerLedgerIdSignal = reactor.use(OwnerLedgerIdSignal)
 
   return createActor((sig) => {
     const nodeIlpAddress = sig.readAndTrack(NodeIlpAddressSignal)
@@ -52,7 +54,7 @@ export const RegisterBtpHttpUpgradeActor = (reactor: Reactor) => {
           type: "btp",
           connectionId,
           ilpAddress: `${nodeIlpAddress}.${localIlpAddressPart}`,
-          accountPath: "builtin/owner/btp",
+          accountPath: `${ownerLedgerIdSignal.read()}:owner/btp`,
         }
 
         logger.debug("handle BTP websocket connection", { connectionId })

packages/app-node/src/backend/ildcp-server/handle-ildcp-requests.ts

@@ -1,6 +1,7 @@
 import { createActor } from "@dassie/lib-reactive"
 import { isFailure } from "@dassie/lib-type-utils"
 
+import { AccountPath } from "../accounting/types/accounts"
 import { ProcessPacketActor } from "../ilp-connector/process-packet"
 import {
   IlpType,
@@ -18,20 +19,21 @@ export interface IldcpRequestParameters {
   requestId: number
 }
 
-const ILDCP_DESTINATION_INFO: IldcpEndpointInfo = {
-  type: "ildcp",
-  ilpAddress: ILDCP_ADDRESS,
-  accountPath: `internal/ildcp`,
-}
-
 export const HandleIldcpRequestsActor = () =>
   createActor((sig) => {
     const ilpRoutingTable = sig.readAndTrack(RoutingTableSignal)
     const processIncomingPacketActor = sig.reactor.use(ProcessPacketActor)
 
+    const ildcpDestinationInfo: IldcpEndpointInfo = {
+      type: "ildcp",
+      ilpAddress: ILDCP_ADDRESS,
+      // ILDCP cannot send or receive money so we set the account path to an impossible value
+      accountPath: "unreachable" as AccountPath,
+    }
+
     ilpRoutingTable.set(ILDCP_ADDRESS, {
       type: "fixed",
-      destination: ILDCP_DESTINATION_INFO,
+      destination: ildcpDestinationInfo,
     })
 
     sig.onCleanup(() => {
@@ -65,7 +67,7 @@ export const HandleIldcpRequestsActor = () =>
         })
 
         processIncomingPacketActor.api.handle.tell({
-          sourceEndpointInfo: ILDCP_DESTINATION_INFO,
+          sourceEndpointInfo: ildcpDestinationInfo,
           serializedPacket: serializeIlpPacket(responsePacket),
           parsedPacket: responsePacket,
           requestId,

packages/app-node/src/backend/ilp-connector/functions/send-packet.ts

@@ -1,5 +1,6 @@
 import { Reactor } from "@dassie/lib-reactive"
 
+import { AccountPath } from "../../accounting/types/accounts"
 import { BtpEndpointInfo, SendBtpPackets } from "../senders/send-btp-packets"
 import {
   IldcpEndpointInfo,
@@ -18,7 +19,7 @@ import { PreparedIlpPacketEvent } from "../topics/prepared-ilp-packet"
 import { ResolvedIlpPacketEvent } from "../topics/resolved-ilp-packet"
 
 export interface CommonEndpointInfo {
-  readonly accountPath: string
+  readonly accountPath: AccountPath
   readonly ilpAddress: string
 }