refactor: dedup token-meta + approval-chain boilerplate

Three behavior-preserving extractions across the prepare_* action builders.

- Hoist the multicall(decimals, symbol) pattern from three local copies
  (compound/actions, morpho/actions, execution/index) into a single
  shared/token-meta.ts helper.
- Hoist the if (approval) { walk tail; attach; return } tail-attach
  pattern that every approve-then-act builder hand-rolled (9 sites across
  compound, morpho, positions, staking) into shared/approval.ts as
  chainApproval().
- Inline the parseAmountFriendly wrapper in positions/actions (it just
  called parseUnits); drop its dead re-export.
- Remove the getLedgerStatus wrapper that only forwarded to
  getSessionStatus; alias the import at the registration site instead.

Net -75 lines across 7 files (+52 / -149). No tool, schema, or response
shape changed. vitest: 442/442 pass.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: szhygulin

src/index.ts

@@ -43,10 +43,10 @@ import { getPortfolioSummaryInput } from "./modules/portfolio/schemas.js";
 import { getSwapQuote, prepareSwap } from "./modules/swap/index.js";
 import { getSwapQuoteInput, prepareSwapInput } from "./modules/swap/schemas.js";
 
+import { getSessionStatus as getLedgerStatus } from "./signing/session.js";
 import {
   pairLedgerLive,
   pairLedgerTron,
-  getLedgerStatus,
   prepareAaveSupply,
   prepareAaveWithdraw,
   prepareAaveBorrow,

src/modules/compound/actions.ts

@@ -1,8 +1,8 @@
 import { encodeFunctionData, parseUnits, maxUint256 } from "viem";
 import { cometAbi } from "../../abis/compound-comet.js";
-import { erc20Abi } from "../../abis/erc20.js";
 import { getClient } from "../../data/rpc.js";
-import { buildApprovalTx, resolveApprovalCap } from "../shared/approval.js";
+import { buildApprovalTx, chainApproval, resolveApprovalCap } from "../shared/approval.js";
+import { resolveTokenMeta } from "../shared/token-meta.js";
 import type {
   PrepareCompoundSupplyArgs,
   PrepareCompoundWithdrawArgs,
@@ -11,21 +11,6 @@ import type {
 } from "./schemas.js";
 import type { SupportedChain, UnsignedTx } from "../../types/index.js";
 
-async function resolveMeta(
-  chain: SupportedChain,
-  asset: `0x${string}`
-): Promise<{ decimals: number; symbol: string }> {
-  const client = getClient(chain);
-  const [decimals, symbol] = await client.multicall({
-    contracts: [
-      { address: asset, abi: erc20Abi, functionName: "decimals" },
-      { address: asset, abi: erc20Abi, functionName: "symbol" },
-    ],
-    allowFailure: false,
-  });
-  return { decimals: Number(decimals), symbol: symbol as string };
-}
-
 async function resolveBaseToken(
   chain: SupportedChain,
   market: `0x${string}`
@@ -76,7 +61,7 @@ export async function buildCompoundSupply(p: PrepareCompoundSupplyArgs): Promise
   const asset = p.asset as `0x${string}`;
   const wallet = p.wallet as `0x${string}`;
   await assertCometActionAllowed(chain, market, "supply");
-  const meta = await resolveMeta(chain, asset);
+  const meta = await resolveTokenMeta(chain, asset);
   const amountWei = parseUnits(p.amount, meta.decimals);
   const { approvalAmount, display } = resolveApprovalCap(
     p.approvalCap,
@@ -107,13 +92,7 @@ export async function buildCompoundSupply(p: PrepareCompoundSupplyArgs): Promise
     description: `Supply ${p.amount} ${meta.symbol} to Compound V3 ${market} on ${chain}`,
     decoded: { functionName: "supply", args: { asset, amount: p.amount, market } },
   };
-  if (approval) {
-    let tail = approval;
-    while (tail.next) tail = tail.next;
-    tail.next = supplyTx;
-    return approval;
-  }
-  return supplyTx;
+  return chainApproval(approval, supplyTx);
 }
 
 export async function buildCompoundWithdraw(p: PrepareCompoundWithdrawArgs): Promise<UnsignedTx> {
@@ -122,7 +101,7 @@ export async function buildCompoundWithdraw(p: PrepareCompoundWithdrawArgs): Pro
   const asset = p.asset as `0x${string}`;
   const wallet = p.wallet as `0x${string}`;
   await assertCometActionAllowed(chain, market, "withdraw");
-  const meta = await resolveMeta(chain, asset);
+  const meta = await resolveTokenMeta(chain, asset);
   const amountWei = p.amount === "max" ? maxUint256 : parseUnits(p.amount, meta.decimals);
   return {
     chain,
@@ -146,7 +125,7 @@ export async function buildCompoundBorrow(p: PrepareCompoundBorrowArgs): Promise
   const wallet = p.wallet as `0x${string}`;
   await assertCometActionAllowed(chain, market, "withdraw");
   const baseToken = await resolveBaseToken(chain, market);
-  const meta = await resolveMeta(chain, baseToken);
+  const meta = await resolveTokenMeta(chain, baseToken);
   const amountWei = parseUnits(p.amount, meta.decimals);
   return {
     chain,
@@ -170,7 +149,7 @@ export async function buildCompoundRepay(p: PrepareCompoundRepayArgs): Promise<U
   const wallet = p.wallet as `0x${string}`;
   await assertCometActionAllowed(chain, market, "supply");
   const baseToken = await resolveBaseToken(chain, market);
-  const meta = await resolveMeta(chain, baseToken);
+  const meta = await resolveTokenMeta(chain, baseToken);
   const amountWei = p.amount === "max" ? maxUint256 : parseUnits(p.amount, meta.decimals);
   let approval: UnsignedTx | null = null;
   if (amountWei !== maxUint256) {
@@ -204,11 +183,5 @@ export async function buildCompoundRepay(p: PrepareCompoundRepayArgs): Promise<U
     description: `Repay ${p.amount === "max" ? "all" : p.amount} ${meta.symbol} on Compound V3 ${market} on ${chain}`,
     decoded: { functionName: "supply(base)", args: { asset: baseToken, amount: p.amount, market } },
   };
-  if (approval) {
-    let tail = approval;
-    while (tail.next) tail = tail.next;
-    tail.next = repayTx;
-    return approval;
-  }
-  return repayTx;
+  return chainApproval(approval, repayTx);
 }

src/modules/execution/index.ts

@@ -5,7 +5,6 @@ import {
   requestSendTransaction,
   getConnectedAccounts,
 } from "../../signing/walletconnect.js";
-import { getSessionStatus } from "../../signing/session.js";
 import {
   consumeHandle,
   retireHandle,
@@ -31,6 +30,7 @@ import {
 } from "../../signing/verification.js";
 import { getClient, verifyChainId } from "../../data/rpc.js";
 import { erc20Abi } from "../../abis/erc20.js";
+import { resolveTokenMeta } from "../shared/token-meta.js";
 import { simulateTx } from "../simulation/index.js";
 import {
   buildAaveSupply,
@@ -133,25 +133,6 @@ export async function pairLedgerTron(args: PairLedgerTronArgs = {}): Promise<{
   };
 }
 
-export async function getLedgerStatus() {
-  return getSessionStatus();
-}
-
-async function resolveAssetMeta(
-  chain: SupportedChain,
-  asset: `0x${string}`
-): Promise<{ decimals: number; symbol: string }> {
-  const client = getClient(chain);
-  const [decimals, symbol] = await client.multicall({
-    contracts: [
-      { address: asset, abi: erc20Abi, functionName: "decimals" },
-      { address: asset, abi: erc20Abi, functionName: "symbol" },
-    ],
-    allowFailure: false,
-  });
-  return { decimals: Number(decimals), symbol: symbol as string };
-}
-
 /** Attach eth_call simulation result, gas estimate, and USD cost. */
 async function enrichTx(tx: UnsignedTx): Promise<UnsignedTx> {
   const client = getClient(tx.chain);
@@ -195,7 +176,7 @@ async function enrichTx(tx: UnsignedTx): Promise<UnsignedTx> {
 // ----- Aave preparation handlers -----
 
 export async function prepareAaveSupply(args: PrepareAaveSupplyArgs): Promise<UnsignedTx> {
-  const meta = await resolveAssetMeta(args.chain as SupportedChain, args.asset as `0x${string}`);
+  const meta = await resolveTokenMeta(args.chain as SupportedChain, args.asset as `0x${string}`);
   return enrichTx(
     await buildAaveSupply({
       wallet: args.wallet as `0x${string}`,
@@ -210,7 +191,7 @@ export async function prepareAaveSupply(args: PrepareAaveSupplyArgs): Promise<Un
 }
 
 export async function prepareAaveWithdraw(args: PrepareAaveWithdrawArgs): Promise<UnsignedTx> {
-  const meta = await resolveAssetMeta(args.chain as SupportedChain, args.asset as `0x${string}`);
+  const meta = await resolveTokenMeta(args.chain as SupportedChain, args.asset as `0x${string}`);
   return enrichTx(
     await buildAaveWithdraw({
       wallet: args.wallet as `0x${string}`,
@@ -224,7 +205,7 @@ export async function prepareAaveWithdraw(args: PrepareAaveWithdrawArgs): Promis
 }
 
 export async function prepareAaveBorrow(args: PrepareAaveBorrowArgs): Promise<UnsignedTx> {
-  const meta = await resolveAssetMeta(args.chain as SupportedChain, args.asset as `0x${string}`);
+  const meta = await resolveTokenMeta(args.chain as SupportedChain, args.asset as `0x${string}`);
   return enrichTx(
     await buildAaveBorrow({
       wallet: args.wallet as `0x${string}`,
@@ -238,7 +219,7 @@ export async function prepareAaveBorrow(args: PrepareAaveBorrowArgs): Promise<Un
 }
 
 export async function prepareAaveRepay(args: PrepareAaveRepayArgs): Promise<UnsignedTx> {
-  const meta = await resolveAssetMeta(args.chain as SupportedChain, args.asset as `0x${string}`);
+  const meta = await resolveTokenMeta(args.chain as SupportedChain, args.asset as `0x${string}`);
   return enrichTx(
     await buildAaveRepay({
       wallet: args.wallet as `0x${string}`,
@@ -269,7 +250,7 @@ export async function prepareLidoUnstake(args: PrepareLidoUnstakeArgs): Promise<
 }
 
 export async function prepareEigenLayerDeposit(args: PrepareEigenLayerDepositArgs): Promise<UnsignedTx> {
-  const meta = await resolveAssetMeta("ethereum", args.token as `0x${string}`);
+  const meta = await resolveTokenMeta("ethereum", args.token as `0x${string}`);
   return enrichTx(
     await buildEigenLayerDeposit({
       wallet: args.wallet as `0x${string}`,
@@ -306,7 +287,7 @@ export async function prepareTokenSend(args: PrepareTokenSendArgs): Promise<Unsi
   const chain = args.chain as SupportedChain;
   const token = args.token as `0x${string}`;
   const to = args.to as `0x${string}`;
-  const meta = await resolveAssetMeta(chain, token);
+  const meta = await resolveTokenMeta(chain, token);
 
   let amountWei: bigint;
   let displayAmount = args.amount;

src/modules/morpho/actions.ts

@@ -1,9 +1,9 @@
 import { encodeFunctionData, parseUnits } from "viem";
 import { morphoBlueAbi, type MorphoMarketParams } from "../../abis/morpho-blue.js";
-import { erc20Abi } from "../../abis/erc20.js";
 import { getClient } from "../../data/rpc.js";
 import { CONTRACTS } from "../../config/contracts.js";
-import { buildApprovalTx, resolveApprovalCap } from "../shared/approval.js";
+import { buildApprovalTx, chainApproval, resolveApprovalCap } from "../shared/approval.js";
+import { resolveTokenMeta } from "../shared/token-meta.js";
 import type {
   PrepareMorphoSupplyArgs,
   PrepareMorphoWithdrawArgs,
@@ -47,21 +47,6 @@ async function resolveMarketParams(
   return { loanToken, collateralToken, oracle, irm, lltv };
 }
 
-async function tokenMeta(
-  chain: SupportedChain,
-  asset: `0x${string}`
-): Promise<{ decimals: number; symbol: string }> {
-  const client = getClient(chain);
-  const [decimals, symbol] = await client.multicall({
-    contracts: [
-      { address: asset, abi: erc20Abi, functionName: "decimals" },
-      { address: asset, abi: erc20Abi, functionName: "symbol" },
-    ],
-    allowFailure: false,
-  });
-  return { decimals: Number(decimals), symbol: symbol as string };
-}
-
 function paramsTuple(p: MorphoMarketParams) {
   return {
     loanToken: p.loanToken,
@@ -77,7 +62,7 @@ export async function buildMorphoSupply(p: PrepareMorphoSupplyArgs): Promise<Uns
   const wallet = p.wallet as `0x${string}`;
   const morpho = morphoAddress(chain);
   const params = await resolveMarketParams(chain, p.marketId as `0x${string}`);
-  const meta = await tokenMeta(chain, params.loanToken);
+  const meta = await resolveTokenMeta(chain, params.loanToken);
   const amountWei = parseUnits(p.amount, meta.decimals);
   const { approvalAmount, display } = resolveApprovalCap(
     p.approvalCap,
@@ -111,21 +96,15 @@ export async function buildMorphoSupply(p: PrepareMorphoSupplyArgs): Promise<Uns
       args: { marketId: p.marketId, amount: p.amount, onBehalf: wallet },
     },
   };
-  if (approval) {
-    let tail = approval;
-    while (tail.next) tail = tail.next;
-    tail.next = supplyTx;
-    return approval;
-  }
-  return supplyTx;
+  return chainApproval(approval, supplyTx);
 }
 
 export async function buildMorphoWithdraw(p: PrepareMorphoWithdrawArgs): Promise<UnsignedTx> {
   const chain = p.chain as SupportedChain;
   const wallet = p.wallet as `0x${string}`;
   const morpho = morphoAddress(chain);
   const params = await resolveMarketParams(chain, p.marketId as `0x${string}`);
-  const meta = await tokenMeta(chain, params.loanToken);
+  const meta = await resolveTokenMeta(chain, params.loanToken);
   // "max" withdraw is encoded as shares=MaxUint256/2 would exceed position; safer to ask by assets with
   // a very large number. Morpho reverts on overdraw, so callers should read their position first.
   // Here we only support explicit amounts for withdraw.
@@ -158,7 +137,7 @@ export async function buildMorphoBorrow(p: PrepareMorphoBorrowArgs): Promise<Uns
   const wallet = p.wallet as `0x${string}`;
   const morpho = morphoAddress(chain);
   const params = await resolveMarketParams(chain, p.marketId as `0x${string}`);
-  const meta = await tokenMeta(chain, params.loanToken);
+  const meta = await resolveTokenMeta(chain, params.loanToken);
   const amountWei = parseUnits(p.amount, meta.decimals);
   return {
     chain,
@@ -183,7 +162,7 @@ export async function buildMorphoRepay(p: PrepareMorphoRepayArgs): Promise<Unsig
   const wallet = p.wallet as `0x${string}`;
   const morpho = morphoAddress(chain);
   const params = await resolveMarketParams(chain, p.marketId as `0x${string}`);
-  const meta = await tokenMeta(chain, params.loanToken);
+  const meta = await resolveTokenMeta(chain, params.loanToken);
   if (p.amount === "max") {
     throw new Error(
       `"max" is not supported for Morpho repay — read borrowShares and pass an explicit amount.`
@@ -222,13 +201,7 @@ export async function buildMorphoRepay(p: PrepareMorphoRepayArgs): Promise<Unsig
       args: { marketId: p.marketId, amount: p.amount, onBehalf: wallet },
     },
   };
-  if (approval) {
-    let tail = approval;
-    while (tail.next) tail = tail.next;
-    tail.next = repayTx;
-    return approval;
-  }
-  return repayTx;
+  return chainApproval(approval, repayTx);
 }
 
 export async function buildMorphoSupplyCollateral(
@@ -238,7 +211,7 @@ export async function buildMorphoSupplyCollateral(
   const wallet = p.wallet as `0x${string}`;
   const morpho = morphoAddress(chain);
   const params = await resolveMarketParams(chain, p.marketId as `0x${string}`);
-  const meta = await tokenMeta(chain, params.collateralToken);
+  const meta = await resolveTokenMeta(chain, params.collateralToken);
   const amountWei = parseUnits(p.amount, meta.decimals);
   const { approvalAmount, display } = resolveApprovalCap(
     p.approvalCap,
@@ -272,13 +245,7 @@ export async function buildMorphoSupplyCollateral(
       args: { marketId: p.marketId, amount: p.amount, onBehalf: wallet },
     },
   };
-  if (approval) {
-    let tail = approval;
-    while (tail.next) tail = tail.next;
-    tail.next = tx;
-    return approval;
-  }
-  return tx;
+  return chainApproval(approval, tx);
 }
 
 export async function buildMorphoWithdrawCollateral(
@@ -288,7 +255,7 @@ export async function buildMorphoWithdrawCollateral(
   const wallet = p.wallet as `0x${string}`;
   const morpho = morphoAddress(chain);
   const params = await resolveMarketParams(chain, p.marketId as `0x${string}`);
-  const meta = await tokenMeta(chain, params.collateralToken);
+  const meta = await resolveTokenMeta(chain, params.collateralToken);
   if (p.amount === "max") {
     throw new Error(
       `"max" is not supported for Morpho withdrawCollateral — read position.collateral and pass an explicit amount.`