feat(bridge-ui): ERC20 Bridge + approval

packages/bridge-ui/src/App.svelte

@@ -5,25 +5,22 @@
   import Navbar from "./components/Navbar.svelte";
   import { SvelteToast } from "@zerodevx/svelte-toast";
 
-  import { onMount } from "svelte";
   import Home from "./pages/home/Home.svelte";
   import { setupI18n } from "./i18n";
   import { BridgeType } from "./domain/bridge";
   import ETHBridge from "./eth/bridge";
   import { bridges, chainIdToBridgeAddress } from "./store/bridge";
   import { CHAIN_MAINNET, CHAIN_TKO } from "./domain/chain";
-
-  const { chains, provider } = configureChains(
-    [mainnet, taiko],
-    [publicProvider()]
-  );
+  import ERC20Bridge from "./erc20/bridge";
 
   setupI18n({ withLocale: "en" });
 
   const ethBridge = new ETHBridge();
+  const erc20Bridge = new ERC20Bridge();
 
   bridges.update((store) => {
     store.set(BridgeType.ETH, ethBridge);
+    store.set(BridgeType.ERC20, erc20Bridge);
     return store;
   });
 
@@ -46,7 +43,6 @@
   <main>
     <Navbar />
     <Router {routes} />
-    <Footer />
   </main>
   <SvelteToast />
 </QueryProvider>

packages/bridge-ui/src/components/buttons/SelectToken.svelte

@@ -1,13 +1,20 @@
 <script lang="ts">
   import { token } from "../../store/token";
-  import { tokens } from "../../domain/token";
+  import { bridgeType } from "../../store/bridge";
+  import { ETH, tokens } from "../../domain/token";
 
   import type { Token } from "../../domain/token";
   import { toast } from "@zerodevx/svelte-toast";
+  import { BridgeType } from "../../domain/bridge";
 
   async function select(t: Token) {
     if (t === $token) return;
     token.set(t);
+    if (t.symbol.toLowerCase() == ETH.symbol.toLowerCase()) {
+      bridgeType.set(BridgeType.ETH);
+    } else {
+      bridgeType.set(BridgeType.ERC20);
+    }
     toast.push(`Token changed to ${t.symbol.toUpperCase()}`);
   }
 </script>

packages/bridge-ui/src/components/form/BridgeForm.svelte

@@ -2,30 +2,87 @@
   import { _ } from "svelte-i18n";
   import { token } from "../../store/token";
   import { fromChain, toChain } from "../../store/chain";
-  import { activeBridge, chainIdToBridgeAddress } from "../../store/bridge";
+  import {
+    activeBridge,
+    chainIdToBridgeAddress,
+    bridgeType,
+  } from "../../store/bridge";
   import { signer } from "../../store/signer";
   import { BigNumber, ethers, Signer } from "ethers";
   import { toast } from "@zerodevx/svelte-toast";
+  import type { Token } from "../../domain/token";
+  import type { BridgeType } from "../../domain/bridge";
+  import type { Chain } from "../../domain/chain";
 
   let amount: string;
+  let requiresAllowance: boolean = true;
   let btnDisabled: boolean = true;
 
   $: isBtnDisabled($signer, amount)
     .then((d) => (btnDisabled = d))
     .catch((e) => console.log(e));
 
+  $: checkAllowance(amount, $token, $bridgeType, $fromChain, $signer)
+    .then((a) => (requiresAllowance = a))
+    .catch((e) => console.log(e));
+
+  async function checkAllowance(
+    amt: string,
+    token: Token,
+    bridgeType: BridgeType,
+    fromChain: Chain,
+    signer: Signer
+  ) {
+    if (!signer || !amt || !token || !fromChain) return true;
+
+    return await $activeBridge.RequiresAllowance({
+      amountInWei: amt
+        ? ethers.utils.parseUnits(amt, token.decimals)
+        : BigNumber.from(0),
+      signer: signer,
+      contractAddress: token.address,
+      spenderAddress: $chainIdToBridgeAddress.get(fromChain.id),
+    });
+  }
+
   async function isBtnDisabled(signer: Signer, amount: string) {
     if (!signer) return true;
     if (!amount) return true;
+    if (requiresAllowance) return true;
     const balance = await signer.getBalance("latest");
     if (balance.lt(ethers.utils.parseUnits(amount, $token.decimals)))
       return true;
 
     return false;
   }
 
+  async function approve() {
+    try {
+      if (!requiresAllowance)
+        throw Error("does not require additional allowance");
+
+      const tx = await $activeBridge.Approve({
+        amountInWei: ethers.utils.parseUnits(amount, $token.decimals),
+        signer: $signer,
+        contractAddress: $token.address,
+        spenderAddress: $chainIdToBridgeAddress.get($fromChain.id),
+      });
+      console.log("approved, waiting for confirmations ", tx);
+      await $signer.provider.waitForTransaction(tx.hash, 3);
+
+      requiresAllowance = false;
+
+      toast.push($_("toast.transactionSent"));
+    } catch (e) {
+      console.log(e);
+      toast.push($_("toast.errorSendingTransaction"));
+    }
+  }
+
   async function bridge() {
     try {
+      if (requiresAllowance) throw Error("requires additional allowance");
+
       const tx = await $activeBridge.Bridge({
         amountInWei: ethers.utils.parseUnits(amount, $token.decimals),
         signer: $signer,
@@ -76,10 +133,20 @@
   </label>
 </div>
 
-<button
-  class="btn btn-accent"
-  on:click={async () => await bridge()}
-  disabled={btnDisabled}
->
-  {$_("home.bridge")}
-</button>
+{#if !requiresAllowance}
+  <button
+    class="btn btn-accent"
+    on:click={bridge}
+    disabled={btnDisabled}
+  >
+    {$_("home.bridge")}
+  </button>
+{:else}
+  <button
+    class="btn btn-accent"
+    on:click={approve}
+    disabled={btnDisabled}
+  >
+    {$_("home.approve")}
+  </button>
+{/if}

packages/bridge-ui/src/constants/abi/ERC20.ts

@@ -0,0 +1,222 @@
+export default [
+  {
+    constant: true,
+    inputs: [],
+    name: "name",
+    outputs: [
+      {
+        name: "",
+        type: "string",
+      },
+    ],
+    payable: false,
+    stateMutability: "view",
+    type: "function",
+  },
+  {
+    constant: false,
+    inputs: [
+      {
+        name: "_spender",
+        type: "address",
+      },
+      {
+        name: "_value",
+        type: "uint256",
+      },
+    ],
+    name: "approve",
+    outputs: [
+      {
+        name: "",
+        type: "bool",
+      },
+    ],
+    payable: false,
+    stateMutability: "nonpayable",
+    type: "function",
+  },
+  {
+    constant: true,
+    inputs: [],
+    name: "totalSupply",
+    outputs: [
+      {
+        name: "",
+        type: "uint256",
+      },
+    ],
+    payable: false,
+    stateMutability: "view",
+    type: "function",
+  },
+  {
+    constant: false,
+    inputs: [
+      {
+        name: "_from",
+        type: "address",
+      },
+      {
+        name: "_to",
+        type: "address",
+      },
+      {
+        name: "_value",
+        type: "uint256",
+      },
+    ],
+    name: "transferFrom",
+    outputs: [
+      {
+        name: "",
+        type: "bool",
+      },
+    ],
+    payable: false,
+    stateMutability: "nonpayable",
+    type: "function",
+  },
+  {
+    constant: true,
+    inputs: [],
+    name: "decimals",
+    outputs: [
+      {
+        name: "",
+        type: "uint8",
+      },
+    ],
+    payable: false,
+    stateMutability: "view",
+    type: "function",
+  },
+  {
+    constant: true,
+    inputs: [
+      {
+        name: "_owner",
+        type: "address",
+      },
+    ],
+    name: "balanceOf",
+    outputs: [
+      {
+        name: "balance",
+        type: "uint256",
+      },
+    ],
+    payable: false,
+    stateMutability: "view",
+    type: "function",
+  },
+  {
+    constant: true,
+    inputs: [],
+    name: "symbol",
+    outputs: [
+      {
+        name: "",
+        type: "string",
+      },
+    ],
+    payable: false,
+    stateMutability: "view",
+    type: "function",
+  },
+  {
+    constant: false,
+    inputs: [
+      {
+        name: "_to",
+        type: "address",
+      },
+      {
+        name: "_value",
+        type: "uint256",
+      },
+    ],
+    name: "transfer",
+    outputs: [
+      {
+        name: "",
+        type: "bool",
+      },
+    ],
+    payable: false,
+    stateMutability: "nonpayable",
+    type: "function",
+  },
+  {
+    constant: true,
+    inputs: [
+      {
+        name: "_owner",
+        type: "address",
+      },
+      {
+        name: "_spender",
+        type: "address",
+      },
+    ],
+    name: "allowance",
+    outputs: [
+      {
+        name: "",
+        type: "uint256",
+      },
+    ],
+    payable: false,
+    stateMutability: "view",
+    type: "function",
+  },
+  {
+    payable: true,
+    stateMutability: "payable",
+    type: "fallback",
+  },
+  {
+    anonymous: false,
+    inputs: [
+      {
+        indexed: true,
+        name: "owner",
+        type: "address",
+      },
+      {
+        indexed: true,
+        name: "spender",
+        type: "address",
+      },
+      {
+        indexed: false,
+        name: "value",
+        type: "uint256",
+      },
+    ],
+    name: "Approval",
+    type: "event",
+  },
+  {
+    anonymous: false,
+    inputs: [
+      {
+        indexed: true,
+        name: "from",
+        type: "address",
+      },
+      {
+        indexed: true,
+        name: "to",
+        type: "address",
+      },
+      {
+        indexed: false,
+        name: "value",
+        type: "uint256",
+      },
+    ],
+    name: "Transfer",
+    type: "event",
+  },
+];