chore: Add new types for i18n (#2121)

Author: PatrykKuniczak

packages/i18n/src/__tests__/types.test.ts

@@ -35,14 +35,16 @@ describe('I18n Types', () => {
   });
 
   describe('With type-safety', () => {
-    const i18n = createI18n<{
+    type MyStructure = {
       simple: { plural: false; substitutions: 0 };
       simpleSub1: { plural: false; substitutions: 1 };
       simpleSub2: { plural: false; substitutions: 2 };
       plural: { plural: true; substitutions: 0 };
       pluralSub1: { plural: true; substitutions: 1 };
       pluralSub2: { plural: true; substitutions: 2 };
-    }>();
+    };
+
+    const i18n = createI18n<MyStructure>();
 
     describe('t', () => {
       it('should only allow passing valid combinations of arguments', () => {

packages/i18n/src/index.ts

@@ -1,16 +1,11 @@
 /** @module @wxt-dev/i18n */
-import {
-  I18nStructure,
-  DefaultI18nStructure,
-  I18n,
-  Substitution,
-} from './types';
+import { I18nStructure, I18n, Substitution, UntypedI18n } from './types';
 import { browser } from '@wxt-dev/browser';
 
-export function createI18n<
-  T extends I18nStructure = DefaultI18nStructure,
->(): I18n<T> {
-  const t = (key: string, ...args: any[]) => {
+export function createI18n(): UntypedI18n;
+export function createI18n<T extends I18nStructure>(): I18n<T>;
+export function createI18n(): UntypedI18n {
+  const t: UntypedI18n['t'] = (key: string, ...args: unknown[]) => {
     // Resolve args
     let sub: Substitution[] | undefined;
     let count: number | undefined;
@@ -64,5 +59,5 @@ export function createI18n<
     }
   };
 
-  return { t } as I18n<T>;
+  return { t };
 }

packages/i18n/src/types.ts

@@ -3,14 +3,23 @@ export interface I18nFeatures {
   substitutions: SubstitutionCount;
 }
 
-export type I18nStructure = {
-  [K: string]: I18nFeatures;
-};
+export interface UntypedI18n {
+  t: UntypedTFunction;
+}
 
-export type DefaultI18nStructure = {
-  [K: string]: any;
+export type UntypedTFunction = {
+  (key: string): string;
+  (key: string, substitutions: Substitution[]): string;
+  (key: string, n: number): string;
+  (key: string, n: number, substitutions: Substitution[]): string;
 };
 
+export type I18nStructure = Record<string, I18nFeatures>;
+
+export interface I18n<T extends I18nStructure> {
+  t: TFunction<T>;
+}
+
 // prettier-ignore
 export type SubstitutionTuple<T extends SubstitutionCount> =
     T extends 1 ? [$1: Substitution]
@@ -66,10 +75,6 @@ export type TFunction<T extends I18nStructure> = {
   ): string;
 };
 
-export interface I18n<T extends DefaultI18nStructure> {
-  t: TFunction<T>;
-}
-
 export type Substitution = string | number;
 
 type SubstitutionCount = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9;