feat: add CrossChainMessenger test scaffold and CrossChainERC20Pair API

packages/sdk/src/interfaces/cross-chain-erc20-pair.ts

+import { Overrides, Contract } from 'ethers'
+import {
+  TransactionRequest,
+  TransactionResponse,
+} from '@ethersproject/abstract-provider'
+import { NumberLike, L1ToL2Overrides } from './types'
+import { ICrossChainMessenger } from './cross-chain-messenger'
+
+/**
+ * Represents an L1<>L2 ERC20 token pair.
+ */
+export interface ICrossChainERC20Pair {
+  /**
+   * Messenger that will be used to carry out cross-chain iteractions.
+   */
+  messenger: ICrossChainMessenger
+
+  /**
+   * Ethers Contract object connected to the L1 token.
+   */
+  l1Token: Contract
+
+  /**
+   * Ethers Contract object connected to the L2 token.
+   */
+  l2Token: Contract
+
+  /**
+   * Deposits some tokens into the L2 chain.
+   *
+   * @param amount Amount of the token to deposit.
+   * @param overrides Optional transaction overrides.
+   * @returns Transaction response for the deposit transaction.
+   */
+  deposit(
+    amount: NumberLike,
+    overrides?: L1ToL2Overrides
+  ): Promise<TransactionResponse>
+
+  /**
+   * Withdraws some tokens back to the L1 chain.
+   *
+   * @param amount Amount of the token to withdraw.
+   * @param overrides Optional transaction overrides.
+   * @returns Transaction response for the withdraw transaction.
+   */
+  withdraw(
+    amount: NumberLike,
+    overrides?: Overrides
+  ): Promise<TransactionResponse>
+
+  /**
+   * Object that holds the functions that generate transactions to be signed by the user.
+   * Follows the pattern used by ethers.js.
+   */
+  populateTransaction: {
+    /**
+     * Generates a transaction for depositing some tokens into the L2 chain.
+     *
+     * @param amount Amount of the token to deposit.
+     * @param overrides Optional transaction overrides.
+     * @returns Transaction that can be signed and executed to deposit the tokens.
+     */
+    deposit(
+      amount: NumberLike,
+      overrides?: L1ToL2Overrides
+    ): Promise<TransactionResponse>
+
+    /**
+     * Generates a transaction for withdrawing some tokens back to the L1 chain.
+     *
+     * @param amount Amount of the token to withdraw.
+     * @param overrides Optional transaction overrides.
+     * @returns Transaction that can be signed and executed to withdraw the tokens.
+     */
+    withdraw(
+      amount: NumberLike,
+      overrides?: Overrides
+    ): Promise<TransactionRequest>
+  }
+
+  /**
+   * Object that holds the functions that estimates the gas required for a given transaction.
+   * Follows the pattern used by ethers.js.
+   */
+  estimateGas: {
+    /**
+     * Estimates gas required to deposit some tokens into the L2 chain.
+     *
+     * @param amount Amount of the token to deposit.
+     * @param overrides Optional transaction overrides.
+     * @returns Transaction that can be signed and executed to deposit the tokens.
+     */
+    deposit(
+      amount: NumberLike,
+      overrides?: L1ToL2Overrides
+    ): Promise<TransactionResponse>
+
+    /**
+     * Estimates gas required to withdraw some tokens back to the L1 chain.
+     *
+     * @param amount Amount of the token to withdraw.
+     * @param overrides Optional transaction overrides.
+     * @returns Transaction that can be signed and executed to withdraw the tokens.
+     */
+    withdraw(
+      amount: NumberLike,
+      overrides?: Overrides
+    ): Promise<TransactionRequest>
+  }
+}

packages/sdk/src/interfaces/cross-chain-messenger.ts

@@ -5,7 +5,6 @@ import {
 } from '@ethersproject/abstract-provider'
 import {
   MessageLike,
-  AddressLike,
   NumberLike,
   CrossChainMessageRequest,
   L1ToL2Overrides,
@@ -67,20 +66,6 @@ export interface ICrossChainMessenger {
     overrides?: Overrides
   ): Promise<TransactionResponse>
 
-  /**
-   * Deposits some tokens into the L2 chain.
-   *
-   * @param token Address of the token to deposit.
-   * @param amount Amount of the token to deposit.
-   * @param overrides Optional transaction overrides.
-   * @returns Transaction response for the deposit transaction.
-   */
-  depositTokens(
-    token: AddressLike,
-    amount: NumberLike,
-    overrides?: L1ToL2Overrides
-  ): Promise<TransactionResponse>
-
   /**
    * Deposits some ETH into the L2 chain.
    *
@@ -93,20 +78,6 @@ export interface ICrossChainMessenger {
     overrides?: L1ToL2Overrides
   ): Promise<TransactionResponse>
 
-  /**
-   * Withdraws some tokens back to the L1 chain.
-   *
-   * @param token Address of the token to withdraw.
-   * @param amount Amount of the token to withdraw.
-   * @param overrides Optional transaction overrides.
-   * @returns Transaction response for the withdraw transaction.
-   */
-  withdrawTokens(
-    token: AddressLike,
-    amount: NumberLike,
-    overrides?: Overrides
-  ): Promise<TransactionResponse>
-
   /**
    * Withdraws some ETH back to the L1 chain.
    *
@@ -166,20 +137,6 @@ export interface ICrossChainMessenger {
       overrides?: Overrides
     ): Promise<TransactionRequest>
 
-    /**
-     * Generates a transaction for depositing some tokens into the L2 chain.
-     *
-     * @param token Address of the token to deposit.
-     * @param amount Amount of the token to deposit.
-     * @param overrides Optional transaction overrides.
-     * @returns Transaction that can be signed and executed to deposit the tokens.
-     */
-    depositTokens(
-      token: AddressLike,
-      amount: NumberLike,
-      overrides?: L1ToL2Overrides
-    ): Promise<TransactionResponse>
-
     /**
      * Generates a transaction for depositing some ETH into the L2 chain.
      *
@@ -192,20 +149,6 @@ export interface ICrossChainMessenger {
       overrides?: L1ToL2Overrides
     ): Promise<TransactionRequest>
 
-    /**
-     * Generates a transaction for withdrawing some tokens back to the L1 chain.
-     *
-     * @param token Address of the token to withdraw.
-     * @param amount Amount of the token to withdraw.
-     * @param overrides Optional transaction overrides.
-     * @returns Transaction that can be signed and executed to withdraw the tokens.
-     */
-    withdrawTokens(
-      token: AddressLike,
-      amount: NumberLike,
-      overrides?: Overrides
-    ): Promise<TransactionRequest>
-
     /**
      * Generates a transaction for withdrawing some ETH back to the L1 chain.
      *
@@ -262,20 +205,6 @@ export interface ICrossChainMessenger {
       overrides?: Overrides
     ): Promise<TransactionRequest>
 
-    /**
-     * Estimates gas required to deposit some tokens into the L2 chain.
-     *
-     * @param token Address of the token to deposit.
-     * @param amount Amount of the token to deposit.
-     * @param overrides Optional transaction overrides.
-     * @returns Transaction that can be signed and executed to deposit the tokens.
-     */
-    depositTokens(
-      token: AddressLike,
-      amount: NumberLike,
-      overrides?: L1ToL2Overrides
-    ): Promise<TransactionResponse>
-
     /**
      * Estimates gas required to deposit some ETH into the L2 chain.
      *
@@ -288,20 +217,6 @@ export interface ICrossChainMessenger {
       overrides?: L1ToL2Overrides
     ): Promise<TransactionRequest>
 
-    /**
-     * Estimates gas required to withdraw some tokens back to the L1 chain.
-     *
-     * @param token Address of the token to withdraw.
-     * @param amount Amount of the token to withdraw.
-     * @param overrides Optional transaction overrides.
-     * @returns Transaction that can be signed and executed to withdraw the tokens.
-     */
-    withdrawTokens(
-      token: AddressLike,
-      amount: NumberLike,
-      overrides?: Overrides
-    ): Promise<TransactionRequest>
-
     /**
      * Estimates gas required to withdraw some ETH back to the L1 chain.
      *

packages/sdk/src/interfaces/index.ts

+export * from './cross-chain-erc20-pair'
 export * from './cross-chain-messenger'
 export * from './cross-chain-provider'
 export * from './l2-provider'

packages/sdk/test/cross-chain-messenger.spec.ts

+/* eslint-disable @typescript-eslint/no-empty-function */
+import './setup'
+
+describe('CrossChainMessenger', () => {
+  describe('sendMessage', () => {
+    describe('when no l2GasLimit is provided', () => {
+      it('should send a message with an estimated l2GasLimit', () => {})
+    })
+
+    describe('when an l2GasLimit is provided', () => {
+      it('should send a message with the provided l2GasLimit', () => {})
+    })
+  })
+
+  describe('resendMessage', () => {
+    describe('when the message being resent exists', () => {
+      it('should resend the message with the new gas limit', () => {})
+    })
+
+    describe('when the message being resent does not exist', () => {
+      it('should throw an error', () => {})
+    })
+  })
+
+  describe('finalizeMessage', () => {
+    describe('when the message being finalized exists', () => {
+      describe('when the message is ready to be finalized', () => {
+        it('should finalize the message', () => {})
+      })
+
+      describe('when the message is not ready to be finalized', () => {
+        it('should throw an error', () => {})
+      })
+
+      // TODO: is this the behavior we want?
+      describe('when the message has already been finalized', () => {
+        it('should throw an error', () => {})
+      })
+    })
+
+    describe('when the message being finalized does not exist', () => {
+      it('should throw an error', () => {})
+    })
+  })
+})