demonstrating attempts to upsert with electrodb

package.json

{
    "name": "upsert-example",
    "version": "1.0.0",
    "description": "Demonstrating attempts to upsert records with electrodb",
    "dependencies": {
        "aws-sdk": "2.544.0",
        "electrodb": "0.9.52"
    }
}

upsert.js

const DynamoDB = require("aws-sdk/clients/dynamodb");
const { Entity } = require("electrodb");

TransactionModel = {
    model: {
        version: "1",
        service: "transactions",
        entity: "transaction",
    },
    attributes: {
        accountId: {
            type: "string",
        },
        transactionId: {
            type: "string",
        },
        amount: {
            type: "number",
        },
    },
    indexes: {
        transaction: {
            pk: {
                field: "PK",
                facets: ["accountId"],
            },
            sk: {
                field: "SK",
                facets: ["transactionId"],
            },
        },
    },
};

const table = "MY_TABLE_NAME";
const client = new DynamoDB.DocumentClient();
const txn = new Entity(TransactionModel, { client, table });

const transaction = {
    accountId: "100",
    transactionId: "1",
    amount: 25,
};

(async () => {
    let result;

    // attempt to upsert a transaction record with `update`
    await txn.delete(transaction).go();
    await txn.update(transaction).set({ amount: 25 }).go();
    result = await txn.get(transaction).go({ includeKeys: true });
    console.log(JSON.stringify(result, null, 4));
    /*
    {
        "amount": 25,
        "SK": "$transaction_1#transactionid_1",
        "PK": "$transactions#accountid_100"
    }
    */

    // compare with transaction record resulting from a `put`
    await txn.delete(transaction).go();
    await txn.put(transaction).go();
    result = await txn.get(transaction).go({ includeKeys: true });
    console.log(JSON.stringify(result, null, 4));
    /*
    {
        "__edb_e__": "transaction",
        "__edb_v__": "1",
        "accountId": "100",
        "amount": 25,
        "SK": "$transaction_1#transactionid_1",
        "PK": "$transactions#accountid_100",
        "transactionId": "1"
    }
    */

    // attempt to upsert a transaction record with `update` part deux
    await txn.delete(transaction).go();
    await txn.update(transaction).set(transaction).go();
    /*
    Error: Attribute accountId is Read-Only and cannot be updated
        at Schema.checkUpdate (/upsert_example/node_modules/electrodb/src/schema.js:394:11)
        at Object.action (/upsert_example/node_modules/electrodb/src/clauses.js:193:37)
        at Object.current.<computed> [as set] (/upsert_example//node_modules/electrodb/src/entity.js:384:34)
        at /upsert_example/upsert.js:66:35
    */
})().catch(console.error);

Notice how the accountId and transactionId attributes are autogenerated when using put, but not with update.