Lesson 5: doubts about deploy.js (publickey&privatekey)

[Finn66]

Hi guys, I wondered, Why is the public key not necessary when we make contract？

Code:

    let provider = new ethers.providers.JsonRpcProvider(process.env.RPC_URL)
    let wallet = new ethers.Wallet(process.env.PRIVATE_KEY, provider)
    const abi = fs.readFileSync("./SimpleStorage_sol_SimpleStorage.abi", "utf8")
    const binary = fs.readFileSync(
        "./SimpleStorage_sol_SimpleStorage.bin",
        "utf8"
    )
    const contractFactory = new ethers.ContractFactory(abi, binary, wallet)
    console.log("Deploying, please wait...")
    const contract = await contractFactory.deploy()

Here is the transaction receipt: (Ganache)

{
  to: null,
  from: '0xf14BfEC2EE5f37bce3aD4F56C8491966c160Aa73',
  ......
}

How does the transaction know my public key when I do not provide it？
Thanks guys.

[Finn66]

Got it,Public key is generated by private key

        const keyPair = getCurve().keyFromPrivate(arrayify(this.privateKey));
        defineReadOnly(this, "publicKey", "0x" + keyPair.getPublic(false, "hex"));
        defineReadOnly(this, "compressedPublicKey", "0x" + keyPair.getPublic(true, "hex"));