From 0fe0d3bec37c442132f1262380284dc94a9d75cd Mon Sep 17 00:00:00 2001
From: Simon Warta <simon@warta.it>
Date: Mon, 10 Feb 2020 17:43:40 +0100
Subject: [PATCH] Add ERC20 support in codec

---
 packages/bcp/src/cosmwasmcodec.spec.ts | 58 ++++++++++++++++++++++++--
 packages/bcp/src/cosmwasmcodec.ts      | 20 +++++----
 packages/bcp/types/cosmwasmcodec.d.ts  | 11 +++--
 3 files changed, 75 insertions(+), 14 deletions(-)

diff --git a/packages/bcp/src/cosmwasmcodec.spec.ts b/packages/bcp/src/cosmwasmcodec.spec.ts
index a061f7f3..d55a2939 100644
--- a/packages/bcp/src/cosmwasmcodec.spec.ts
+++ b/packages/bcp/src/cosmwasmcodec.spec.ts
@@ -1,16 +1,16 @@
 import { CosmosAddressBech32Prefix } from "@cosmwasm/sdk";
-import { PostableBytes, PrehashType } from "@iov/bcp";
+import { Address, PostableBytes, PrehashType, SendTransaction, TokenTicker } from "@iov/bcp";
 import { Encoding } from "@iov/encoding";
 
 import { CosmWasmCodec } from "./cosmwasmcodec";
 import { chainId, nonce, sendTxJson, signedTxBin, signedTxEncodedJson, signedTxJson } from "./testdata.spec";
-import { BankTokens } from "./types";
+import { BankToken, Erc20Token } from "./types";
 
 const { toUtf8 } = Encoding;
 
 const defaultPrefix = "cosmos" as CosmosAddressBech32Prefix;
 
-const defaultTokens: BankTokens = [
+const defaultBankTokens: readonly BankToken[] = [
   {
     fractionalDigits: 6,
     ticker: "ATOM",
@@ -18,8 +18,26 @@ const defaultTokens: BankTokens = [
   },
 ];
 
+const defaultErc20Tokens: readonly Erc20Token[] = [
+  {
+    contractAddress: "cosmos18vd8fpwxzck93qlwghaj6arh4p7c5n89uzcee5",
+    fractionalDigits: 5,
+    ticker: "ASH",
+  },
+  {
+    contractAddress: "cosmos1hqrdl6wstt8qzshwc6mrumpjk9338k0lr4dqxd",
+    fractionalDigits: 0,
+    ticker: "BASH",
+  },
+  {
+    contractAddress: "cosmos18r5szma8hm93pvx6lwpjwyxruw27e0k5uw835c",
+    fractionalDigits: 18,
+    ticker: "CASH",
+  },
+];
+
 describe("CosmWasmCodec", () => {
-  const codec = new CosmWasmCodec(defaultPrefix, defaultTokens);
+  const codec = new CosmWasmCodec(defaultPrefix, defaultBankTokens, defaultErc20Tokens);
 
   describe("isValidAddress", () => {
     it("accepts valid addresses", () => {
@@ -48,6 +66,38 @@ describe("CosmWasmCodec", () => {
       };
       expect(codec.bytesToSign(sendTxJson, nonce)).toEqual(expected);
     });
+
+    it("works for ERC20 send", () => {
+      const bashSendTx: SendTransaction = {
+        kind: "bcp/send",
+        chainId: chainId,
+        sender: "cosmos1txqfn5jmcts0x0q7krdxj8tgf98tj0965vqlmq" as Address,
+        recipient: "cosmos1dddd" as Address,
+        memo: "My first BASH payment",
+        amount: {
+          fractionalDigits: 6,
+          quantity: "345",
+          tokenTicker: "BASH" as TokenTicker,
+        },
+        fee: {
+          tokens: {
+            fractionalDigits: 6,
+            quantity: "2500",
+            tokenTicker: "ATOM" as TokenTicker,
+          },
+          gasLimit: "100000",
+        },
+      };
+
+      const expected = {
+        bytes: toUtf8(
+          '{"account_number":"0","chain_id":"cosmoshub-3","fee":{"amount":[{"amount":"2500","denom":"uatom"}],"gas":"100000"},"memo":"My first BASH payment","msgs":[{"type":"wasm/execute","value":{"contract":"cosmos1hqrdl6wstt8qzshwc6mrumpjk9338k0lr4dqxd","msg":{"transfer":{"amount":"345","recipient":"cosmos1dddd"}},"sender":"cosmos1txqfn5jmcts0x0q7krdxj8tgf98tj0965vqlmq","sent_funds":[]}}],"sequence":"99"}',
+        ),
+        prehashType: PrehashType.Sha256,
+      };
+
+      expect(codec.bytesToSign(bashSendTx, nonce)).toEqual(expected);
+    });
   });
 
   describe("bytesToPost", () => {
diff --git a/packages/bcp/src/cosmwasmcodec.ts b/packages/bcp/src/cosmwasmcodec.ts
index 447694c6..21a2c55c 100644
--- a/packages/bcp/src/cosmwasmcodec.ts
+++ b/packages/bcp/src/cosmwasmcodec.ts
@@ -26,19 +26,25 @@ import { pubkeyToAddress } from "./address";
 import { Caip5 } from "./caip5";
 import { parseTx } from "./decode";
 import { buildSignedTx, buildUnsignedTx } from "./encode";
-import { BankTokens, nonceToAccountNumber, nonceToSequence } from "./types";
+import { BankTokens, Erc20Token, nonceToAccountNumber, nonceToSequence } from "./types";
 
 export class CosmWasmCodec implements TxCodec {
   private readonly addressPrefix: CosmosAddressBech32Prefix;
-  private readonly tokens: BankTokens;
+  private readonly bankTokens: BankTokens;
+  private readonly erc20Tokens: readonly Erc20Token[];
 
-  public constructor(addressPrefix: CosmosAddressBech32Prefix, tokens: BankTokens) {
+  public constructor(
+    addressPrefix: CosmosAddressBech32Prefix,
+    bankTokens: BankTokens,
+    erc20Tokens: readonly Erc20Token[] = [],
+  ) {
     this.addressPrefix = addressPrefix;
-    this.tokens = tokens;
+    this.bankTokens = bankTokens;
+    this.erc20Tokens = erc20Tokens;
   }
 
   public bytesToSign(unsigned: UnsignedTransaction, nonce: Nonce): SigningJob {
-    const built = buildUnsignedTx(unsigned, this.tokens);
+    const built = buildUnsignedTx(unsigned, this.bankTokens, this.erc20Tokens);
 
     const nonceInfo: types.NonceInfo = {
       account_number: nonceToAccountNumber(nonce),
@@ -61,7 +67,7 @@ export class CosmWasmCodec implements TxCodec {
   // PostableBytes are JSON-encoded StdTx
   public bytesToPost(signed: SignedTransaction): PostableBytes {
     // TODO: change this as well (return StdTx, not AminoTx)?
-    const built = buildSignedTx(signed, this.tokens);
+    const built = buildSignedTx(signed, this.bankTokens, this.erc20Tokens);
     return marshalTx(built.value) as PostableBytes;
   }
 
@@ -79,7 +85,7 @@ export class CosmWasmCodec implements TxCodec {
       throw new Error("Nonce is required");
     }
     const parsed = unmarshalTx(bytes);
-    return parseTx(parsed, chainId, nonce, this.tokens);
+    return parseTx(parsed, chainId, nonce, this.bankTokens);
   }
 
   public identityToAddress(identity: Identity): Address {
diff --git a/packages/bcp/types/cosmwasmcodec.d.ts b/packages/bcp/types/cosmwasmcodec.d.ts
index e9429a00..c44c38b5 100644
--- a/packages/bcp/types/cosmwasmcodec.d.ts
+++ b/packages/bcp/types/cosmwasmcodec.d.ts
@@ -11,11 +11,16 @@ import {
   TxCodec,
   UnsignedTransaction,
 } from "@iov/bcp";
-import { BankTokens } from "./types";
+import { BankTokens, Erc20Token } from "./types";
 export declare class CosmWasmCodec implements TxCodec {
   private readonly addressPrefix;
-  private readonly tokens;
-  constructor(addressPrefix: CosmosAddressBech32Prefix, tokens: BankTokens);
+  private readonly bankTokens;
+  private readonly erc20Tokens;
+  constructor(
+    addressPrefix: CosmosAddressBech32Prefix,
+    bankTokens: BankTokens,
+    erc20Tokens?: readonly Erc20Token[],
+  );
   bytesToSign(unsigned: UnsignedTransaction, nonce: Nonce): SigningJob;
   bytesToPost(signed: SignedTransaction): PostableBytes;
   identifier(_signed: SignedTransaction): TransactionId;