Error from ethers.utils.AbiCoder()

[emclab]

Here is a code which decoder logs retrieved with getLogs in v5.3:

const decoder = new ethers.utils.AbiCoder();
const decodedLogs = logs.map(log => {
        // remember how we separated indexed and unindexed events?
        // it was because we need to sort them differently here
        const decodedTopics = indexedInputs.map( input => {
            // we use the position of the type in the array as an index for the
            // topic, we need to add 1 since the first topic is the event sig
            const value = decoder.decode(  //<<== cause error
                input.type,
                log.topics[indexedInputs.indexOf(input) + 1]
            );
            return `${input.name}: ${value}`;
        })
        const decodedDataRaw = decoder.decode(unindexedInputs, log.data);
        const decodedData = unindexedInputs.forEach((input, i) => {
            return `${input.name}: ${decodedDataRaw[i]}`
        });
    });

The error is:

(node:15412) UnhandledPromiseRejectionWarning: TypeError: types.map is not a function
    at AbiCoder.decode (C:\d\code\js\xjc_bbone\node_modules\@ethersproject\abi\lib\abi-coder.js:98:28)

Here is the data feed for the code above:

Logs returned :  [
  {
    blockNumber: 1490906,
    blockHash: '0xb6960de8913a11396432a50c1153defb55caf35defae51fb6422053918f2779d',
    transactionIndex: 0,
    removed: false,
    address: '0xD873bF1fcF2fB83148A43F266153E70066F7E777',
    data: '0x0000000000000000000000000000000000000000204fce5e3e25026110000000',
    topics: [
      '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef',
      '0x0000000000000000000000000000000000000000000000000000000000000000',
      '0x00000000000000000000000010b368d6072107d7e92137f0d2bca0549f81730d'
    ],
    transactionHash: '0x643a5bef77166192f4092a730fa37469e0e07f14772abb8d6af3c8d94b5c135f',
    logIndex: 0
  },
  {
    blockNumber: 1512135,
    blockHash: '0x69a6886766b252388db07ecabf43b47d00589db0eb759e802e59d45e77f7d314',
    transactionIndex: 0,
    removed: false,
    address: '0xD873bF1fcF2fB83148A43F266153E70066F7E777',
    data: '0x0000000000000000000000000000000000000000000000056bc75e2d63100000',
    topics: [
      '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef',
      '0x00000000000000000000000010b368d6072107d7e92137f0d2bca0549f81730d',
      '0x00000000000000000000000005eb9d3a023b480e494b0d498501cdb9a34d1224'
    ],
    transactionHash: '0x0d992df90a8e7451860e57b9a5587bfbce41bf48973b27ca2f12bd6789948272',
    logIndex: 0
  },
  {
    blockNumber: 1552694,
    blockHash: '0x6a20cb27868c1e797e231bdb7b45d765fad11ddff66cee4e6044519f1a150181',
    transactionIndex: 0,
    removed: false,
    address: '0xD873bF1fcF2fB83148A43F266153E70066F7E777',
    data: '0x0000000000000000000000000000000000000000000000008ac7230489e80000',
    topics: [
      '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef',
      '0x00000000000000000000000010b368d6072107d7e92137f0d2bca0549f81730d',
      '0x00000000000000000000000005eb9d3a023b480e494b0d498501cdb9a34d1224'
    ],
    transactionHash: '0x782bb4caae340eef3eda83ef5416ede88e57e743962d4c516477ed54948d82f0',
    logIndex: 0
  },
  {
    blockNumber: 1552856,
    blockHash: '0x59b3f0d9b70944b758cb44dcccff474ddd98e04fbda7fa36078c83eae8ad2c45',
    transactionIndex: 0,
    removed: false,
    address: '0xD873bF1fcF2fB83148A43F266153E70066F7E777',
    data: '0x0000000000000000000000000000000000000000000000008ac7230489e80000',
    topics: [
      '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef',
      '0x00000000000000000000000010b368d6072107d7e92137f0d2bca0549f81730d',
      '0x00000000000000000000000005eb9d3a023b480e494b0d498501cdb9a34d1224'
    ],
    transactionHash: '0x8133b0b34ea37e2545f7412277df4ecb7d545ebf5410f6d214f9f843ca9a8db8',
    logIndex: 0
  }
]
IndexedInputs :  [
  {
    indexed: true,
    internalType: 'address',
    name: 'from',
    type: 'address'
  },
  {
    indexed: true,
    internalType: 'address',
    name: 'to',
    type: 'address'
  }
]

[zemse]

variable.map is not a function, sounds like somewhere array was expected but it got a non-array value. The decode docs seem to be asking to pass in types while seems you're pasing a stirng input.type. Can you try passing in an array or make it [input.type]

(I'm not very familiar with using AbiCoder directly) It seems you want to decode getLogs, Interface sohuld help you:

const iface = new ethers.utils.Interface(abi);
const parsed = iface.parseLog(log)

[emclab]

zemse, [input.type] did eliminate error. I notice in doc that AbiCoder() is seldom used by developer and the doc mentions interface. But interface seems not easy to understand at the first place. If you have any example or further reading, please don't hesitate to recommend. Thanks.

The example of decoding event logs I am following is here.

[zemse]

The example I provided is pretty much it

const logs = await provider.getLogs(filter); // your code

// pass the abi and create interface object
const iface = new ethers.utils.Interface(['event Transfer(address,address,uint)']);

const parsedLogs = logs.map(log => iface.parseLog(log)) // pass each log to parseLog method

const firstParsedLog = parsedLogs[0];

// you get parsed values under the args property.
firstParsedLog.args[0] // from
firstParsedLog.args[1] // to
firstParsedLog.args[2] // value