Files
initiative/packages/domain/src/edit-combatant.ts

63 lines
1.5 KiB
TypeScript

import type { DomainEvent } from "./events.js";
import type { CombatantId, DomainError, Encounter } from "./types.js";
export interface EditCombatantSuccess {
readonly encounter: Encounter;
readonly events: DomainEvent[];
}
/**
* Pure function that renames a combatant in an encounter by ID.
*
* FR-001: Accepts Encounter, CombatantId, and newName; returns next state + events.
* FR-002: Emits a CombatantUpdated event with combatantId, oldName, newName.
* FR-004: Rejects empty/whitespace-only names with DomainError.
* FR-005: Preserves activeIndex and roundNumber.
* FR-006: Preserves combatant list order.
*/
export function editCombatant(
encounter: Encounter,
id: CombatantId,
newName: string,
): EditCombatantSuccess | DomainError {
const trimmed = newName.trim();
if (trimmed === "") {
return {
kind: "domain-error",
code: "invalid-name",
message: "Combatant name must not be empty",
};
}
const index = encounter.combatants.findIndex((c) => c.id === id);
if (index === -1) {
return {
kind: "domain-error",
code: "combatant-not-found",
message: `No combatant found with ID "${id}"`,
};
}
const oldName = encounter.combatants[index].name;
return {
encounter: {
combatants: encounter.combatants.map((c) =>
c.id === id ? { ...c, name: trimmed } : c,
),
activeIndex: encounter.activeIndex,
roundNumber: encounter.roundNumber,
},
events: [
{
type: "CombatantUpdated",
combatantId: id,
oldName,
newName: trimmed,
},
],
};
}