watcher-ts/packages/erc721-watcher/demo.md

Demo

• For setup follow the steps in Readme.

• Run the watcher:

  yarn server
  

• Run the job-runner:

  yarn job-runner
  

• Deploy an ERC721 token:

  yarn nft:deploy
  # NFT deployed to: NFT_ADDRESS
  

  Export the address of the deployed token to a shell variable for later use:

  export NFT_ADDRESS="<NFT_ADDRESS>"
  

• Run the following GQL mutation in generated watcher GraphQL endpoint http://127.0.0.1:3006/graphql

  mutation {
    watchContract(
      address: "NFT_ADDRESS"
      kind: "ERC721"
      checkpoint: true
    )
  }
  

• Connect MetaMask to http://localhost:8545 (with chain ID 41337)

• Add a second account to Metamask and export the account address to a shell variable for later use:

  export RECIPIENT_ADDRESS="<RECIPIENT_ADDRESS>"
  

• To get the current block hash at any time, run:

  yarn block:latest
  

• Run the following GQL query (eth_call) in generated watcher GraphQL endpoint http://127.0.0.1:3006/graphql

  query {
    name(
      blockHash: "LATEST_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
    ) {
      value
      proof {
        data
      }
    }
    symbol(
      blockHash: "LATEST_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
    ) {
      value
      proof {
        data
      }
    }
    balanceOf(
      blockHash: "LATEST_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
      owner: "0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc"
    ) {
      value
      proof {
        data
      }
    }
  }
  

• Run the following GQL query (storage) in generated watcher GraphQL endpoint http://127.0.0.1:3006/graphql

  query {
    _name(
      blockHash: "LATEST_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
    ) {
      value
      proof {
        data
      }
    }
    _symbol(
      blockHash: "LATEST_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
    ) {
      value
      proof {
        data
      }
    }
    _balances(
      blockHash: "LATEST_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
      key0: "0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc"
    ) {
      value
      proof {
        data
      }
    }
  }
  

• Run the following GQL subscription in generated watcher GraphQL endpoint:

  subscription {
    onEvent {
      event {
        __typename
        ... on TransferEvent {
          from
          to
          tokenId
        },
        ... on ApprovalEvent {
          owner
          approved
          tokenId
        }
      },
      block {
        number
        hash
      }
    }
  }
  

• Mint token

  yarn nft:mint --nft $NFT_ADDRESS --to 0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc --token-id 1
  

  • A Transfer event to 0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc shall be visible in the subscription at endpoint.

  • An auto-generated diff_staged IPLDBlock should be added with parent CID pointing to the initial checkpoint IPLDBlock.

  • Custom property transferCount should be 1 initially.

• Run the getState query at the endpoint to get the latest IPLDBlock for NFT_ADDRESS:

  query {
    getState (
      blockHash: "EVENT_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
      # kind: "checkpoint"
      # kind: "diff"
      kind: "diff_staged"
    ) {
      cid
      block {
        cid
        hash
        number
        timestamp
        parentHash
      }
      contractAddress
      data
    }
  }
  

  • diff IPLDBlocks get created corresponding to the diff_staged blocks when their respective eth_blocks reach the pruned region.

  • data contains the default state and also the custom state property transferCount that is indexed in hooks.ts file.

• Get the latest blockHash and run the following query for balanceOf and ownerOf (eth_call):

  query {
    fromBalanceOf: balanceOf(
      blockHash: "LATEST_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
      owner: "0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc"
    ) {
      value
      proof {
        data
      }
    }
    toBalanceOf: balanceOf(
      blockHash: "LATEST_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
      owner: "RECIPIENT_ADDRESS"
    ) {
      value
      proof {
        data
      }
    }
    ownerOf(
      blockHash: "LATEST_BLOCK_HASH"
      contractAddress: "NFT_ADDRESS"
      tokenId: 1
    ) {
      value
      proof {
        data
      }
    }
  }
  

• Transfer token

  yarn nft:transfer --nft $NFT_ADDRESS --from 0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc --to $RECIPIENT_ADDRESS --token-id 1
  

  • An Approval event for ZERO_ADDRESS (0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc) shall be visible in the subscription at endpoint.

  • A Transfer event to $RECIPIENT_ADDRESS shall be visible in the subscription at endpoint.

  • An auto-generated diff_staged IPLDBlock should be added with parent CID pointing to the previous IPLDBlock.

  • Custom property transferCount should be incremented after transfer. This can be checked in the getState query and in IPFS webUI mentioned in the later steps.

• Get the latest blockHash and replace the blockHash in the above query. The result should be different and the token should be transferred to the recipient.

• Run the getState query again at the endpoint with the event blockHash.

• After the diff block has been created (can check if event block number pruned in yarn server log), create a checkpoint using CLI in packages/erc721-watcher:

  yarn checkpoint --address $NFT_ADDRESS
  

  • Run the getState query again with the output blockHash and kind checkpoint at the endpoint.

  • The latest checkpoint should have the aggregate of state diffs since the last checkpoint.

  • The IPLDBlock entries can be seen in pg-admin in table ipld_block.

• All the diff and checkpoint IPLDBlocks should pushed to IPFS.

• Open IPFS WebUI http://127.0.0.1:5001/webui and search for IPLDBlocks using their CIDs.

• The state should have auto indexed data and also custom property transferCount according to code in hooks file handleEvent method.