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How To Deploy A Smart Contract

In order to deploy a smart contract using eosjs, call the setcode followed by the setabi actions of the eosio account.

setcode

setcode takes the name of the account where the smart contract will be deployed to and the smart contract .wasm file. The smart contract .wasm file should be a hex string. Assuming that a valid .wasm file is located at /mypath/my_smart_contract.wasm, converting a smart contract to a hex string can be accomplished using the code below.

const fs = require('fs')
const wasmFilePath = '/mypath/my_smart_contract.wasm'
const wasmHexString = fs.readFileSync(wasmFilePath).toString('hex')

In the example shown below useraaaaaaaa sets the account useraaaaaaaa's code to the smart contract located at /mypath/my_smart_contract.wasm's hex string representation.

        {
          account: 'eosio',
          name: 'setcode',
          authorization: [
            {
              actor: 'useraaaaaaaa',
              permission: 'active',
            },
          ],
          data: {
            account: 'useraaaaaaaa',
            code: wasmHexString,
          },
        }

setabi

setabi takes the name of the account where the smart contract will be deployed to and the serialized .abi file corresponding to the .wasm used in the setcode action corresponding to this setabi action. The following code is provided to serialize .abi files.

const fs = require('fs')

const buffer = new Serialize.SerialBuffer({
    textEncoder: api.textEncoder,
    textDecoder: api.textDecoder,
})

const abiFilePath = '/mypath/my_smart_contract.abi'
let abiJSON = JSON.parse(fs.readFileSync(abiFilePath, 'utf8'))
const abiDefinitions = api.abiTypes.get('abi_def')

abiJSON = abiDefinitions.fields.reduce(
    (acc, { name: fieldName }) =>
        Object.assign(acc, { [fieldName]: acc[fieldName] || [] }),
        abiJSON
    )
abiDefinitions.serialize(buffer, abiJSON)
serializedAbiHexString = Buffer.from(buffer.asUint8Array()).toString('hex')

Note that the api object from initialization is used for it's textEncoderand textDecoder objects, as well as it's abiTypes map.

This line in particular:

abiJSON = abiDefinitions.fields.reduce(
    (acc, { name: fieldName }) =>
        Object.assign(acc, { [fieldName]: acc[fieldName] || [] }),
        abiJSON
    )

ensures that the .abi file contains the fields that an .abi file is expected to contain. Note that if an expected field is missing, the call to serialize will throw an exception indicating the missing field.

Deploying a Smart Contract

Below the two actions are submitted as one transaction using the Api object.

(async () => {
  await api.transact({
      actions: [
        {
          account: 'eosio',
          name: 'setcode',
          authorization: [
            {
              actor: 'useraaaaaaaa',
              permission: 'active',
            },
          ],
          data: {
            account: 'useraaaaaaaa',
            code: wasmHexString,
          },
        },
        {
          account: 'eosio',
          name: 'setabi',
          authorization: [
            {
              actor: 'useraaaaaaaa',
              permission: 'active',
            },
          ],
          data: {
            account: 'useraaaaaaaa',
            abi: serializedAbiHexString,
          },
        },
      ],
    },
    {
      blocksBehind: 3,
      expireSeconds: 30,
    });
})();

The entire code is provided below for reference.

const wasmFilePath = '/mypath/my_smart_contract.wasm'
const abiFilePath = '/mypath/my_smart_contract.abi'

const wasmHexString = fs.readFileSync(wasmFilePath).toString('hex')

const buffer = new Serialize.SerialBuffer({
    textEncoder: api.textEncoder,
    textDecoder: api.textDecoder,
})

let abiJSON = JSON.parse(fs.readFileSync(abiFilePath, 'utf8'))
const abiDefinitions = api.abiTypes.get('abi_def')
abiJSON = abiDefinitions.fields.reduce(
    (acc, { name: fieldName }) =>
        Object.assign(acc, { [fieldName]: acc[fieldName] || [] }),
        abiJSON
    )
abiDefinitions.serialize(buffer, abiJSON)
serializedAbiHexString = Buffer.from(buffer.asUint8Array()).toString('hex')

await api.transact(
    {
      actions: [
        {
          account: 'eosio',
          name: 'setcode',
          authorization: [
            {
              actor: 'useraaaaaaaa',
              permission: 'active',
            },
          ],
          data: {
            account: 'useraaaaaaaa',
            code: wasmHexString,
          },
        },
        {
          account: 'eosio',
          name: 'setabi',
          authorization: [
            {
              actor: 'useraaaaaaaa',
              permission: 'active',
            },
          ],
          data: {
            account: 'useraaaaaaaa',
            abi: serializedAbiHexString,
          },
        },
      ],
    },
    {
      blocksBehind: 3,
      expireSeconds: 30,
    }
  )