tsconfig.json

{
    "extends": "./node_modules/@polkadot/dev/config/tsconfig",
    "compilerOptions":
    {
      "target": "es2017",
      "module": "commonjs",
      "moduleResolution": "node",
      "jsx": "react",
      "noImplicitAny": true,
      "allowSyntheticDefaultImports": true,
      "resolveJsonModule": true,

      "declaration": true,
      "sourceMap": true,
      "importHelpers": true,

      /* Module Resolution Options */
      "esModuleInterop": true,

      "baseUrl": ".",
      "paths":
      {
        "@polkadot/api": ["packages/api/src"],
        "@polkadot/api/*": ["packages/api/src/*"],
        "@polkadot/api-derive": ["packages/api-derive/src"],
        "@polkadot/api-derive/*": ["packages/api-derive/src/*"],
        "@polkadot/rpc-core": ["packages/rpc-core/src"],
        "@polkadot/rpc-core/*": ["packages/rpc-core/src/*"],
        "@polkadot/rpc-provider": ["packages/rpc-provider/src"],
        "@polkadot/rpc-provider/*": ["packages/rpc-provider/src/*"],
        "@polkadot/rpc-rx": ["packages/rpc-rx/src"],
        "@polkadot/rpc-rx/*": ["packages/rpc-rx/src/*"],
        "@polkadot/extrinsics": ["packages/type-extrinsics/src"],
        "@polkadot/extrinsics/*": ["packages/type-extrinsics/src/*"],
        "@polkadot/jsonrpc": ["packages/type-jsonrpc/src"],
        "@polkadot/jsonrpc/*": ["packages/type-jsonrpc/src/*"],
        "@polkadot/storage": ["packages/type-storage/src"],
        "@polkadot/storage/*": ["packages/type-storage/src/*"],
        "@polkadot/types": ["packages/types/src"],
        "@polkadot/types/*": ["packages/types/src/*"]
      },
      "typeRoots": [
        "./node_modules/@polkadot/ts",
        "./node_modules/@types"
      ],

      /* Strict Type-Checking Options */
      "strict": true,
      "skipLibCheck": true
    }
  }