Add basic escrow with create, accept and release

escrow/.gitignore

@@ -0,0 +1 @@
+.lib

escrow/daml.yaml

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+sdk-version: 2.10.2
+name: escrow
+source: daml
+version: 0.0.1
+dependencies:
+  - daml-prim
+  - daml-script-lts
+  - daml-stdlib
+data-dependencies:
+  # LUNAR DOLLAR PROJECT
+  - ../lunar-dollar/.daml/dist/lunar-dollar-1.0.0.dar
+  # INTERFACE DEPENDENCIES
+  - .lib/daml-finance-interface-account.dar
+  - .lib/daml-finance-interface-holding.dar
+  - .lib/daml-finance-interface-instrument-base.dar
+  - .lib/daml-finance-interface-instrument-token.dar
+  - .lib/daml-finance-interface-lifecycle.dar
+  - .lib/daml-finance-interface-settlement.dar
+  - .lib/daml-finance-interface-types-common.dar
+  - .lib/daml-finance-interface-util.dar
+  # IMPLEMENTATION DEPENDENCIES
+  - .lib/daml-finance-account.dar
+  - .lib/daml-finance-holding.dar
+  - .lib/daml-finance-instrument-token.dar
+  - .lib/daml-finance-lifecycle.dar
+  - .lib/daml-finance-settlement.dar
+init-script: Scripts.SetupAll:setupAll
+build-options:
+  - --target=1.17
+  - -Wno-upgrade-interfaces
+  - -Wno-upgrade-exceptions
+

escrow/daml/Escrow.daml

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+module Escrow where
+
+import Daml.Finance.Interface.Holding.V4.Holding qualified as Holding (I)
+import Daml.Finance.Interface.Types.Common.V3.Types (AccountKey, InstrumentKey)
+
+import Holding.Transfer (splitAndTransfer)
+
+template EscrowProposal
+  with
+    buyer : Party
+    seller : Party
+    arbiter : Party
+    bank : Party
+    instrumentKey : InstrumentKey
+    amount : Decimal
+    buyerAccount : AccountKey
+    sellerAccount : AccountKey
+    escrowAccount : AccountKey
+    description : Text
+  where
+    signatory buyer
+    observer seller, bank, arbiter
+
+    ensure amount > 0.0
+
+    choice Accept : ContractId Escrow
+      with
+        holdingCid : ContractId Holding.I
+      controller seller, bank
+      do
+        escrowHoldingCid <- splitAndTransfer [buyer, bank] escrowAccount amount holdingCid
+        create Escrow with
+          buyer
+          seller
+          arbiter
+          bank
+          instrumentKey
+          amount
+          sellerAccount
+          escrowAccount
+          escrowHoldingCid
+          description
+
+    choice Cancel : ()
+      controller buyer
+      do pure ()
+
+template Escrow
+  with
+    buyer : Party
+    seller : Party
+    arbiter : Party
+    bank : Party
+    instrumentKey : InstrumentKey
+    amount : Decimal
+    sellerAccount : AccountKey
+    escrowAccount : AccountKey
+    escrowHoldingCid : ContractId Holding.I
+    description : Text
+  where
+    signatory buyer, seller
+    observer bank, arbiter
+
+    choice Release : ContractId Holding.I
+      controller buyer, bank
+      do
+        splitAndTransfer [bank, seller] sellerAccount amount escrowHoldingCid
+

escrow/daml/Scripts/Escrow.daml

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+module Scripts.Escrow where
+
+import Daml.Script
+
+import Daml.Finance.Interface.Holding.V4.Holding qualified as Holding (I)
+import Daml.Finance.Interface.Types.Common.V3.Types (AccountKey(..), Id(..))
+
+import Escrow (EscrowProposal(..), Escrow, Accept(..), Release(..))
+import Scripts.Util (lookupParty, getLNRD)
+
+data CreateEscrowProposalArgs = CreateEscrowProposalArgs with
+  buyer : Text
+  seller : Text
+  arbiter : Text
+  amount : Decimal
+  description : Text
+
+createEscrowProposal : CreateEscrowProposalArgs -> Script (ContractId EscrowProposal)
+createEscrowProposal args = do
+  buyer <- lookupParty args.buyer
+  seller <- lookupParty args.seller
+  arbiter <- lookupParty args.arbiter
+  bank <- lookupParty "Bank"
+  (_, lnrd) <- getLNRD
+
+  let
+    buyerAccount = AccountKey with custodian = bank; owner = buyer; id = Id (args.buyer <> "'s Account")
+    sellerAccount = AccountKey with custodian = bank; owner = seller; id = Id (args.seller <> "'s Account")
+    escrowAccount = AccountKey with custodian = bank; owner = bank; id = Id "Escrow Account"
+
+  proposalCid <- submit buyer do
+    createCmd EscrowProposal with
+      buyer
+      seller
+      arbiter
+      bank
+      instrumentKey = lnrd.instrumentKey
+      amount = args.amount
+      buyerAccount
+      sellerAccount
+      escrowAccount
+      description = args.description
+
+  debug $ "Created escrow proposal for " <> show args.amount <> " LNRD"
+  pure proposalCid
+
+data AcceptEscrowArgs = AcceptEscrowArgs with
+  buyer : Text
+  seller : Text
+  proposalCid : ContractId EscrowProposal
+  holdingCid : ContractId Holding.I
+
+acceptEscrow : AcceptEscrowArgs -> Script (ContractId Escrow)
+acceptEscrow args = do
+  seller <- lookupParty args.seller
+  bank <- lookupParty "Bank"
+
+  escrowCid <- submitMulti [seller, bank] [] do
+    exerciseCmd args.proposalCid Accept with
+      holdingCid = args.holdingCid
+
+  debug "Escrow funded"
+  pure escrowCid
+
+data ReleaseEscrowArgs = ReleaseEscrowArgs with
+  buyer : Text
+  escrowCid : ContractId Escrow
+
+releaseEscrow : ReleaseEscrowArgs -> Script (ContractId Holding.I)
+releaseEscrow args = do
+  buyer <- lookupParty args.buyer
+  bank <- lookupParty "Bank"
+
+  holdingCid <- submitMulti [buyer, bank] [] do
+    exerciseCmd args.escrowCid Release
+
+  debug "Escrow released to seller"
+  pure holdingCid
+

escrow/daml/Scripts/Setup.daml

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+module Scripts.Setup where
+
+import Daml.Script
+
+import Daml.Finance.Interface.Account.V4.Factory qualified as AccountFactory (I)
+import Daml.Finance.Interface.Types.Common.V3.Types (AccountKey, HoldingFactoryKey(..), Id(..))
+
+import Scripts.Util (lookupParty, createBankAccount)
+
+setupEscrow : Script AccountKey
+setupEscrow = do
+  bank <- lookupParty "Bank"
+  alice <- lookupParty "Alice"
+  bob <- lookupParty "Bob"
+
+  [(accountFactoryCid, _)] <- queryInterface @AccountFactory.I bank
+  let holdingFactory = HoldingFactoryKey with provider = bank; id = Id "Holding Factory"
+
+  escrowAccount <- createBankAccount bank holdingFactory accountFactoryCid bank "Escrow Account" [alice, bob]
+  debug "Created bank escrow account"
+  pure escrowAccount
+

escrow/daml/Scripts/SetupAll.daml

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+module Scripts.SetupAll where
+
+import Daml.Script
+
+import Daml.Finance.Interface.Types.Common.V3.Types (AccountKey)
+
+import LunarDollar.Setup (setupLunarDollar)
+import Scripts.Setup (setupEscrow)
+
+setupAll : Script AccountKey
+setupAll = do
+  setupLunarDollar
+  setupEscrow
+

escrow/daml/Tests/EscrowTest.daml

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+module Tests.EscrowTest where
+
+import Daml.Script
+
+import Scripts.SetupAll (setupAll)
+import Scripts.Mint (MintArgs(..), mint)
+import Scripts.Balance (BalanceArgs(..), balance)
+import Scripts.Escrow
+  ( CreateEscrowProposalArgs(..), createEscrowProposal
+  , AcceptEscrowArgs(..), acceptEscrow
+  , ReleaseEscrowArgs(..), releaseEscrow
+  )
+
+testEscrowHappyPath : Script ()
+testEscrowHappyPath = do
+  _ <- setupAll
+
+  debug "=== Escrow Happy Path Test ==="
+
+  holdingCid <- mint MintArgs with
+    recipient = "Alice"
+    amount = 50.0
+
+  debug "1. Alice has 50 LNRD"
+  balance BalanceArgs with party = "Alice"
+
+  proposalCid <- createEscrowProposal CreateEscrowProposalArgs with
+    buyer = "Alice"
+    seller = "Bob"
+    arbiter = "Bank"
+    amount = 50.0
+    description = "Test escrow"
+
+  debug "2. Alice created escrow proposal for 50 LNRD"
+
+  escrowCid <- acceptEscrow AcceptEscrowArgs with
+    buyer = "Alice"
+    seller = "Bob"
+    proposalCid
+    holdingCid
+
+  debug "3. Escrow funded — LNRD locked in escrow account"
+  balance BalanceArgs with party = "Alice"
+
+  _ <- releaseEscrow ReleaseEscrowArgs with
+    buyer = "Alice"
+    escrowCid
+
+  debug "4. Buyer released — LNRD transferred to seller"
+  balance BalanceArgs with party = "Alice"
+  balance BalanceArgs with party = "Bob"
+
+  pure ()
+
+testEscrowWithSplit : Script ()
+testEscrowWithSplit = do
+  _ <- setupAll
+
+  debug "=== Escrow With Split Test ==="
+
+  holdingCid <- mint MintArgs with
+    recipient = "Alice"
+    amount = 200.0
+
+  debug "1. Alice has 200 LNRD"
+
+  proposalCid <- createEscrowProposal CreateEscrowProposalArgs with
+    buyer = "Alice"
+    seller = "Bob"
+    arbiter = "Bank"
+    amount = 75.0
+    description = "Partial escrow"
+
+  debug "2. Alice created escrow proposal for 75 LNRD"
+
+  escrowCid <- acceptEscrow AcceptEscrowArgs with
+    buyer = "Alice"
+    seller = "Bob"
+    proposalCid
+    holdingCid
+
+  debug "3. Escrow funded — 75 LNRD locked, 125 LNRD remains with Alice"
+  balance BalanceArgs with party = "Alice"
+
+  _ <- releaseEscrow ReleaseEscrowArgs with
+    buyer = "Alice"
+    escrowCid
+
+  debug "4. Released — Alice: 125 LNRD, Bob: 75 LNRD"
+  balance BalanceArgs with party = "Alice"
+  balance BalanceArgs with party = "Bob"
+
+  pure ()
+

escrow/get-dependencies.sh

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+#!/usr/bin/env bash
+# Copyright (c) 2024 Digital Asset (Switzerland) GmbH and/or its affiliates. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+set -euo pipefail
+
+# Create .lib directory
+if [[ -d .lib ]]; then
+  rm -r .lib
+fi
+mkdir .lib
+
+# Get the dependency list
+echo "Downloading the list of dependencies"
+version="0.0.6"
+curl -L# \
+  -H 'Cache-Control: no-cache, no-store' \
+  -o .lib/${version}.conf \
+  https://raw.githubusercontent.com/digital-asset/daml-finance/main/docs/code-samples/tutorials-config/${version}.conf
+
+# For each dependency, download and install
+while IFS=" " read -r url out
+do
+  printf "Downloading: %s, to: %s\n" "$url" "$out"
+  curl -Lf# "${url}" -o ${out}
+done < .lib/${version}.conf
+
+echo "All dependencies successfully downloaded!"
+

get-dependencies.sh

@@ -22,6 +22,12 @@ echo ">>> vault"
 cd "$SCRIPT_DIR/vault"
 ./get-dependencies.sh
 
+# Escrow
+echo ""
+echo ">>> escrow"
+cd "$SCRIPT_DIR/escrow"
+./get-dependencies.sh
+
 echo ""
 echo "========================================"
 echo "All dependencies downloaded successfully!"

lunar-dollar/daml/Scripts/Setup.daml

@@ -5,13 +5,12 @@ import DA.Map qualified as Map (fromList)
 import DA.Set qualified as Set (fromList, empty)
 
 import Daml.Finance.Interface.Account.V4.Factory qualified as AccountFactory (I)
-import Daml.Finance.Interface.Types.Common.V3.Types (AccountKey(..))
+import Daml.Finance.Interface.Types.Common.V3.Types (AccountKey(..), Id(..), HoldingStandard(..), InstrumentKey(..))
 
 import LunarDollar (LunarDollar(..))
 import LunarDollar qualified
 import Daml.Finance.Interface.Instrument.Token.V4.Factory qualified as TokenFactory (Create(..), I)
 import Daml.Finance.Interface.Instrument.Token.V4.Types (Token(..))
-import Daml.Finance.Interface.Types.Common.V3.Types (Id(..), HoldingStandard(..), InstrumentKey(..))
 
 import Daml.Finance.Account.V4.Account qualified as Account (Factory(..))
 import Daml.Finance.Holding.V4.Factory qualified as Holding (Factory(..))

multi-package.yaml

@@ -1,3 +1,4 @@
 packages:
   - ./vault
   - ./lunar-dollar
+  - ./escrow