bug:L2Block.fromFields() is not reconstructing the object (aztec.js)

[FilipHarald]

I'm trying to store the block in a DB and then serve it over an API. But when I retrieve the stored (JSON)data from the DB and send over an API I can't reconstruct the L2Block-object from the data. I know there are to/fromString and to/fromBuffer, but I want to make the data stored in DB queryable.

When trying to use fromFields with the JSON-data it works, but the object is not fully reconstructed. Also, the necessary types are not exported so that I can reconstruct the object.

I've reproduced it here. But the gist of it is this....

import { L2Block } from "@aztec/aztec.js";
// ... receiving `block`
  const jsonString = JSON.stringify(block, null, 2);
  const recreatedObj = L2Block.fromFields(JSON.parse(jsonString) as L2Block);
  logger.info(`Fields: ${JSON.stringify(recreatedObj, null, 2)}`);
  // below line produces an error
  logger.info(`Fields: ${recreatedObj.hash()}`);
// ...

...produces this...

TypeError: this.header.hash is not a function
    at L2Block.hash (/usr/main/node_modules/@aztec/circuit-types/src/l2_block.ts:139:24)
    at Object.store (/usr/main/services/explorer-api/src/database/models/block.ts:36:30)
    at onBlock (/usr/main/services/explorer-api/src/event-handler/on-block.ts:6:17)
    ...

[FilipHarald]

When trying to reconstruct the obj required for fromFields I get stuck at not being able to import AppendOnlyTreeSnapshot for re-creation. It seems to be plenty of more classes that's not able to import.

[benesjan]

Hello @FilipHarald, we've decided to just remove the function as it's non-essential. Please use toBuffer and fromBuffer methods when you need block serialization. Thank you for reporting