initiative/packages/application/src/__tests__/helpers.ts

import type { Encounter, PlayerCharacter } from "@initiative/domain";
import { isDomainError } from "@initiative/domain";
import type { EncounterStore, PlayerCharacterStore } from "../ports.js";

export function requireSaved<T>(value: T | null): T {
	if (value === null) throw new Error("Expected store.saved to be non-null");
	return value;
}

export function expectSuccess<T>(
	result: T,
): asserts result is Exclude<T, { kind: "domain-error" }> {
	if (isDomainError(result)) {
		throw new Error(`Expected success, got domain error: ${result.message}`);
	}
}

export function expectError(result: unknown): asserts result is {
	kind: "domain-error";
	code: string;
	message: string;
} {
	if (!isDomainError(result)) {
		throw new Error("Expected domain error");
	}
}

export function stubEncounterStore(
	initial: Encounter,
): EncounterStore & { saved: Encounter | null } {
	const stub = {
		saved: null as Encounter | null,
		get: () => initial,
		save: (e: Encounter) => {
			stub.saved = e;
			stub.get = () => e;
		},
	};
	return stub;
}

export function stubPlayerCharacterStore(
	initial: readonly PlayerCharacter[],
): PlayerCharacterStore & { saved: readonly PlayerCharacter[] | null } {
	const stub = {
		saved: null as readonly PlayerCharacter[] | null,
		getAll: () => [...initial],
		save: (characters: PlayerCharacter[]) => {
			stub.saved = characters;
			stub.getAll = () => [...characters];
		},
	};
	return stub;
}