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Canister declarations

PicJS creates actors from a canister’s Candid interface: an idlFactory that encodes and decodes calls, and a _SERVICE type that describes them. Generate both from the canister’s .did file with @icp-sdk/bindgen:

Terminal window
npx @icp-sdk/bindgen --did-file ./counter.did --out-dir ./tests --actor-disabled

This writes tests/declarations/counter.did.js and tests/declarations/counter.did.d.ts. --actor-disabled skips the actor wrapper, which PicJS doesn’t need.

The declarations export everything PicJS needs, for example in tests/src/counter.spec.ts:

import { IDL } from '@icp-sdk/core/candid';
import { _SERVICE, idlFactory, init } from '../declarations/counter.did';


const fixture = await pic.setupCanister<_SERVICE>({
  idlFactory,
  wasm: WASM_PATH,
  arg: IDL.encode(init({ IDL }), [countInitArg]),
});

init describes the canister’s init arguments, so arg can be encoded with the same types the canister expects.