feat(coin-evm): implement validateIntent

Author: francois-guerin-ledger

.changeset/perfect-icons-type.md

@@ -0,0 +1,5 @@
+---
+"@ledgerhq/coin-evm": minor
+---
+
+feat(coin-evm): implement `validateIntent`

libs/coin-modules/coin-evm/src/api/index.ts

@@ -27,6 +27,7 @@ import {
   listOperations,
   getBalance,
   getSequence,
+  validateIntent,
 } from "../logic/index";
 
 export function createApi(config: EvmConfig, currencyId: CryptoCurrencyId): Api {
@@ -64,8 +65,7 @@ export function createApi(config: EvmConfig, currencyId: CryptoCurrencyId): Api
       throw new Error("getRewards is not supported");
     },
     getSequence: (address: string): Promise<number> => getSequence(currency, address),
-    validateIntent(_intent: TransactionIntent): Promise<TransactionValidation> {
-      throw new Error("validateIntent is not supported");
-    },
+    validateIntent: (intent: TransactionIntent): Promise<TransactionValidation> =>
+      validateIntent(currency, intent),
   };
 }

libs/coin-modules/coin-evm/src/logic/common.ts

@@ -1,6 +1,58 @@
 import { ethers } from "ethers";
 import { TransactionTypes } from "ethers/lib/utils";
+import { FeeEstimation } from "@ledgerhq/coin-framework/api/types";
 import ERC20ABI from "../abis/erc20.abi.json";
+import { ApiFeeData, ApiGasOptions } from "../types";
+
+export function isApiGasOptions(options: unknown): options is ApiGasOptions {
+  if (!options || typeof options !== "object") return false;
+
+  return (
+    "slow" in options &&
+    isApiFeeData(options.slow) &&
+    "medium" in options &&
+    isApiFeeData(options.medium) &&
+    "fast" in options &&
+    isApiFeeData(options.fast)
+  );
+}
+
+export function isApiFeeData(fees: unknown): fees is ApiFeeData {
+  if (!fees || typeof fees !== "object") return false;
+
+  const isBigIntOrNull = (value: unknown): boolean => value === null || typeof value === "bigint";
+
+  return (
+    "maxFeePerGas" in fees &&
+    isBigIntOrNull(fees.maxFeePerGas) &&
+    "maxPriorityFeePerGas" in fees &&
+    isBigIntOrNull(fees.maxPriorityFeePerGas) &&
+    "gasPrice" in fees &&
+    isBigIntOrNull(fees.gasPrice) &&
+    "nextBaseFee" in fees &&
+    isBigIntOrNull(fees.nextBaseFee)
+  );
+}
+
+type LegacyFeeEstimation = FeeEstimation & { parameters: { gasPrice: bigint } };
+type Eip1559FeeEstimation = FeeEstimation & {
+  parameters: { maxFeePerGas: bigint; maxPriorityFeePerGas: bigint };
+};
+
+export function isLegacyFeeEstimation(
+  estimation: FeeEstimation,
+): estimation is LegacyFeeEstimation {
+  return typeof estimation.parameters?.gasPrice === "bigint";
+}
+
+export function isEip1559FeeEstimation(
+  estimation: FeeEstimation,
+): estimation is Eip1559FeeEstimation {
+  return (
+    typeof estimation.parameters?.maxFeePerGas === "bigint" &&
+    typeof estimation.parameters?.maxPriorityFeePerGas === "bigint"
+  );
+}
 
 export function getTransactionType(intentType: string): TransactionTypes {
   if (!["send-legacy", "send-eip1559"].includes(intentType)) {

libs/coin-modules/coin-evm/src/logic/index.ts

@@ -6,3 +6,4 @@ export * from "./estimateFees";
 export * from "./listOperations";
 export * from "./craftTransaction";
 export * from "./getSequence";
+export * from "./validateIntent";