Truffle migration with TypeScript

Question

I've been able to run truffle tests successfully using TypeScript, but when it comes to migration, I get stuck.

1) My current setup:

tsconfig.json

{
    "compilerOptions": {
      "target": "es5",                          
      "module": "commonjs",                    
      "lib": ["es6"],                     
      "allowJs": true,
      "outDir": "build",                          
      "rootDir": "src",
      "strict": true,         
      "noImplicitAny": true,
      "esModuleInterop": true,
      "resolveJsonModule": true,
      "types": ["@types/node", "@types/chai", "@types/mocha"],
      "typeRoots": ["./node_modules/@types", "./types"],
    },
  }

truffle-config.js

require("ts-node").register({
  files: true,
});
//...

2) Migration files:

1_initial_migration.js

const Migrations = artifacts.require("Migrations");

module.exports = function (deployer) {
  deployer.deploy(Migrations);
};

2_deploy_contracts.js

module.exports = require("./2_deploy_contracts.ts");

2_deploy_contracts.ts

const Fallback = artifacts.require('Fallback');

module.exports = async (
  deployer: Truffle.Deployer,
  network: string,
  accounts: string[]
) => deployer.deploy(Fallback);

3) Problem:

I am using an intermediate file 2_deploy_contracts.js that is calling 2_deploy_contracts.ts, since Truffle apparently is ignoring the ts migration files.

Problem is that some types are not defined when trying to deploy the contracts:

$ truffle deploy --network development --reset

Error description:

migrations/2_deploy_contracts.ts:10:18 - error TS2304: Cannot find name 'artifacts'.

10 const Fallback = artifacts.require('Fallback');

migrations/2_deploy_contracts.ts:13:13 - error TS2503: Cannot find namespace 'Truffle'.

13 deployer: Truffle.Deployer,

Any idea on how to define types for artifacts and Truffle, or a workaround to run the migration files with TypeScript successfully?

Answer 1

You need to generate the types using typechain and inject the variable from 2_deploy_contracts.js

npx typechain --target=truffle-v5 'build/contracts/*.json'

module.exports = require("./2_deploy_contracts.ts")(artifacts);

2_deploy_contracts.ts

module.exports = (artifacts: Truffle.Artifacts) => {
  return async (
    deployer: Truffle.Deployer,
    network: string,
    accounts: string[]
  ) => {
    artifacts.require('Fallback');
    deployer.deploy(Fallback);
  }
}