LIVE-1292 Cover Polkadot existential deposit edge case (#1953)

* Fix transaction mode mapping

Send max must be balances.transfer palletMethod instead of balances.transferKeepAlive

* Fix 1 DOT Polkadot limitation

On the Polkadot network, an address is only active when it holds a minimum amount, currently set at 1 DOT.
There's a limitation when you hold ~ 1 DOT.
Use recommended 1.1 DOT value.

* Improve code readability

Don't use ternary operator

* Split Existential Deposit and margin

Restore EXISTENTIAL_DEPOSIT, use new constant EXISTENTIAL_DEPOSIT_RECOMMENDED_MARGIN to handle recommended margin

src/families/polkadot/js-getTransactionStatus.ts

@@ -36,6 +36,7 @@ import {
   calculateAmount,
   getMinimumAmountToBond,
   getMinimumBalance,
+  EXISTENTIAL_DEPOSIT_RECOMMENDED_MARGIN,
 } from "./logic";
 import { isValidAddress } from "./address";
 import { getCurrentPolkadotPreloadData } from "./preload";
@@ -78,6 +79,12 @@ const getSendTransactionStatus = async (
   const leftover = a.spendableBalance.minus(totalSpent);
 
   if (
+    a.spendableBalance.lte(
+      EXISTENTIAL_DEPOSIT.plus(EXISTENTIAL_DEPOSIT_RECOMMENDED_MARGIN)
+    )
+  ) {
+    errors.amount = new NotEnoughBalance();
+  } else if (
     minimumBalanceExistential.gt(0) &&
     leftover.lt(minimumBalanceExistential) &&
     leftover.gt(0)

src/families/polkadot/js-signOperation.ts

@@ -29,6 +29,7 @@ const MODE_TO_TYPE = {
 };
 const MODE_TO_PALLET_METHOD = {
   send: "balances.transferKeepAlive",
+  sendMax: "balances.transfer",
   bond: "staking.bond",
   bondExtra: "staking.bondExtra",
   unbond: "staking.unbond",
@@ -41,16 +42,15 @@ const MODE_TO_PALLET_METHOD = {
 };
 
 const getExtra = (type: string, account: Account, transaction: Transaction) => {
-  const extra = MODE_TO_PALLET_METHOD[transaction.mode]
-    ? {
-        palletMethod:
-          MODE_TO_PALLET_METHOD[
-            transaction.mode === "bond" && !isFirstBond(account)
-              ? "bondExtra"
-              : transaction.mode
-          ],
-      }
-    : {};
+  const extra = {
+    palletMethod: MODE_TO_PALLET_METHOD[transaction.mode],
+  };
+
+  if (transaction.mode == "send" && transaction.useAllAmount) {
+    extra.palletMethod = MODE_TO_PALLET_METHOD["sendMax"];
+  } else if (transaction.mode === "bond" && !isFirstBond(account)) {
+    extra.palletMethod = MODE_TO_PALLET_METHOD["bondExtra"];
+  }
 
   switch (type) {
     case "OUT":

src/families/polkadot/logic.ts

@@ -4,6 +4,7 @@ import type { Transaction } from "./types";
 import { getCurrentPolkadotPreloadData } from "./preload";
 
 export const EXISTENTIAL_DEPOSIT = new BigNumber(10000000000);
+export const EXISTENTIAL_DEPOSIT_RECOMMENDED_MARGIN = new BigNumber(1000000000); // Polkadot recommended Existential Deposit error margin
 export const MAX_NOMINATIONS = 16;
 export const MAX_UNLOCKINGS = 32;
 export const PRELOAD_MAX_AGE = 60 * 1000;