Lesson 7 - what's the purpose of connect()

[nsawit]

In 7:47:25, Patrick used connect() method to show us how the encrypted key can be used. But why did we need this? The initial code we had didn't have to use connect() method

Using encrypted private key

const encryptedJson = fs.readFileSync("./encrypted.json", "utf8");
  let wallet = new ethers.Wallet.fromEncryptedJsonSync(
    encryptedJson,
    process.env.PSW
  );
  wallet = await wallet.connect(provider);

VS

We didn't use connect() method here in our initial code

  const provider = new ethers.providers.JsonRpcProvider(process.env.RPC_URL);
  const wallet = new ethers.Wallet(process.env.PRIVATE_KEY, provider);

  const abi = fs.readFileSync("./SimpleStorage_sol_SimpleStorage.abi", "utf8");
  const bin = fs.readFileSync("./SImpleStorage_sol_SimpleStorage.bin", "utf8");

  const contractFactory = new ethers.ContractFactory(abi, bin, wallet);

[krakxn]

It is so that our instance of the decrypted wallet here

let wallet = new ethers.Wallet.fromEncryptedJsonSync(
    encryptedJson,
    process.env.PSW
  );

can then be instead used to get an instance of the new wallet; which—in this case—is the same decrypted wallet but connected to the provider you provide.

From docs:

"Creates a new Wallet instance from an existing instance, connected to a new provider."

"A connected Provider which allows the wallet to connect to the Ethereum network to query its state and send transactions, or null if no provider is connected.

To change the provider, use the connect method, which will return a new instance of the Wallet connected to the provider."

Entire read: https://docs.ethers.io/v4/api-wallet.html

[othaime-en]

To add on this, we didn't use .connect() method in your second piece of code because we connected the wallet (private key) to the provider in the line.
const wallet = new ethers.Wallet(process.env.PRIVATE_KEY, provider)
passing provider as the second parameter automatically connected our wallet to the provider, so using .connect() would be unnecessary

[krakxn]

^ The above too.

A QoL tip: In addition—to people reading this—I would recommend always to keep the codebase modular and clean, how can we do that in this case? It can be done so by not initially providing a provider (provider is optional, as in docs) when we create our wallet instance. Then, we can make use of several mutator methods to create a new wallet instance in accordance with specific (different) providers.

That way, it will much easier to track and edit for the devs.

Can also preferably use Wallet.provider, as above whilst keeping the functions for modularity.