add abstract SmartContract classes

src/contracts/SmartContract.ts

@@ -0,0 +1,46 @@
+import Web3 from 'web3'
+import { AbiItem } from 'web3-utils'
+import { Config, ConfigHelper } from '../config'
+import { amountToUnits, unitsToAmount } from '../utils'
+
+export abstract class SmartContract {
+  public web3: Web3
+  public config: Config
+  public abi: AbiItem | AbiItem[]
+
+  abstract getDefaultAbi(): AbiItem | AbiItem[]
+
+  /**
+   * Instantiate the smart contract.
+   * @param {Web3} web3
+   * @param {string | number} network Network id or name
+   * @param {Config} config Configutation of the smart contract
+   * @param {AbiItem | AbiItem[]} abi ABI of the smart contract
+   */
+  constructor(
+    web3: Web3,
+    network?: string | number,
+    config?: Config,
+    abi?: AbiItem | AbiItem[]
+  ) {
+    this.web3 = web3
+    this.config = config || new ConfigHelper().getConfig(network || 'unknown')
+    this.abi = abi || (this.getDefaultAbi() as AbiItem[])
+  }
+
+  async amountToUnits(
+    token: string,
+    amount: string,
+    tokenDecimals?: number
+  ): Promise<string> {
+    return amountToUnits(this.web3, token, amount, tokenDecimals)
+  }
+
+  async unitsToAmount(
+    token: string,
+    amount: string,
+    tokenDecimals?: number
+  ): Promise<string> {
+    return unitsToAmount(this.web3, token, amount, tokenDecimals)
+  }
+}

src/contracts/SmartContractWithAddress.ts

@@ -0,0 +1,34 @@
+import Web3 from 'web3'
+import { Contract } from 'web3-eth-contract'
+import { AbiItem } from 'web3-utils'
+import { Config } from '../config'
+import { setContractDefaults } from '../utils'
+import { SmartContract } from '.'
+
+export abstract class SmartContractWithAddress extends SmartContract {
+  public address: string
+  public contract: Contract
+
+  /**
+   * Instantiate the smart contract.
+   * @param {string} address Address of the smart contract
+   * @param {Web3} web3
+   * @param {string | number} network Network id or name
+   * @param {Config} config Configutation of the smart contract
+   * @param {AbiItem | AbiItem[]} abi ABI of the smart contract
+   */
+  constructor(
+    address: string,
+    web3: Web3,
+    network?: string | number,
+    config?: Config,
+    abi?: AbiItem | AbiItem[]
+  ) {
+    super(web3, network, config, abi)
+    this.address = address
+    this.contract = setContractDefaults(
+      new this.web3.eth.Contract(this.getDefaultAbi(), this.address),
+      this.config
+    )
+  }
+}

src/contracts/index.ts

@@ -1,3 +1,5 @@
+export * from './SmartContract'
+export * from './SmartContractWithAddress'
 export * from './factories/NFTFactory'
 export * from './pools/Dispenser'
 export * from './pools/FixedRateExchange'