i18n: Support enforcing variables object conditionality

Author: PartMan7

src/i18n/types.ts

@@ -38,12 +38,14 @@ type InferVariables<T extends string> = T extends `${infer Prefix}{{${infer Vari
 	? InferVariables<Prefix> | Variable | InferVariables<Suffix>
 	: never;
 export type BaseLookup = Exclude<keyof RefTextMap, number | symbol>;
-export type VariablesFromLookup<Lookup extends BaseLookup> = InferVariables<RefTextMap[Lookup]>;
-
-export type TranslationFn = <Lookup extends BaseLookup>(
-	lookup: Lookup,
-	variables?: Record<VariablesFromLookup<Lookup>, string | number | undefined>
-) => TranslatedText;
+export type VariablesFromLookup<Lookup extends BaseLookup> =
+	InferVariables<RefTextMap[Lookup]> extends `${infer Variables}`
+		? [Variables] extends [never]
+			? []
+			: [Record<Variables, string | number | undefined>]
+		: [];
+
+export type TranslationFn = <Lookup extends BaseLookup>(lookup: Lookup, ...variables: VariablesFromLookup<Lookup>) => TranslatedText;
 
 type ReplaceStringWithTranslatedText<TParams extends readonly unknown[]> = {
 	[K in keyof TParams]: TParams[K] extends string ? TranslatedText : TParams[K];

src/ps/games/game.ts

@@ -118,9 +118,9 @@ export class BaseGame<State extends BaseState> {
 	applyMod?(mod: string): ActionResponse<TranslatedText>;
 	canBroadcastFinish?(): boolean;
 
-	throw<Lookup extends BaseLookup>(msg?: Lookup, vars?: Record<VariablesFromLookup<Lookup>, string | number | undefined>): never {
-		if (!msg) throw new ChatError(this.$T('GAME.INVALID_INPUT'));
-		throw new ChatError(this.$T(msg, vars));
+	throw<Lookup extends BaseLookup>(...params: [Lookup, ...VariablesFromLookup<NonNullable<Lookup>>] | []): never {
+		if (params.length === 0) throw new ChatError(this.$T('GAME.INVALID_INPUT'));
+		throw new ChatError(this.$T(...(params as [Lookup, ...VariablesFromLookup<Lookup>])));
 	}
 
 	constructor(ctx: BaseContext) {