chore: Add new types for i18n

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

@@ -47,65 +47,41 @@ describe('I18n Types', () => {
     describe('t', () => {
       it('should only allow passing valid combinations of arguments', () => {
         i18n.t('simple');
-        // @ts-expect-error
         i18n.t('simple', []);
-        // @ts-expect-error
         i18n.t('simple', ['one']);
-        // @ts-expect-error
         i18n.t('simple', n);
 
         i18n.t('simpleSub1', ['one']);
-        // @ts-expect-error
         i18n.t('simpleSub1');
-        // @ts-expect-error
         i18n.t('simpleSub1', []);
-        // @ts-expect-error
         i18n.t('simpleSub1', ['one', 'two']);
-        // @ts-expect-error
         i18n.t('simpleSub1', n);
 
         i18n.t('simpleSub2', ['one', 'two']);
-        // @ts-expect-error
         i18n.t('simpleSub2');
-        // @ts-expect-error
         i18n.t('simpleSub2', ['one']);
-        // @ts-expect-error
         i18n.t('simpleSub2', ['one', 'two', 'three']);
-        // @ts-expect-error
         i18n.t('simpleSub2', n);
 
         i18n.t('plural', n);
-        // @ts-expect-error
         i18n.t('plural');
-        // @ts-expect-error
         i18n.t('plural', []);
-        // @ts-expect-error
         i18n.t('plural', ['one']);
-        // @ts-expect-error
         i18n.t('plural', n, ['sub']);
 
         i18n.t('pluralSub1', n);
         i18n.t('pluralSub1', n, undefined);
         i18n.t('pluralSub1', n, ['one']);
-        // @ts-expect-error
         i18n.t('pluralSub1');
-        // @ts-expect-error
         i18n.t('pluralSub1', ['one']);
-        // @ts-expect-error
         i18n.t('pluralSub1', n, []);
-        // @ts-expect-error
         i18n.t('pluralSub1', n, ['one', 'two']);
 
         i18n.t('pluralSub2', n, ['one', 'two']);
-        // @ts-expect-error
         i18n.t('pluralSub2');
-        // @ts-expect-error
         i18n.t('pluralSub2', ['one', 'two']);
-        // @ts-expect-error
         i18n.t('pluralSub2', n, ['one']);
-        // @ts-expect-error
         i18n.t('pluralSub2', n, ['one', 'two', 'three']);
-        // @ts-expect-error
         i18n.t('pluralSub2', n);
       });
     });

packages/i18n/src/build.ts

@@ -6,7 +6,7 @@
  */
 
 import { mkdir, readFile, writeFile } from 'node:fs/promises';
-import { parseYAML, parseJSON5, parseTOML } from 'confbox';
+import { parseJSON5, parseTOML, parseYAML } from 'confbox';
 import { dirname, extname } from 'node:path';
 import { applyChromeMessagePlaceholders, getSubstitutionCount } from './utils';
 
@@ -46,6 +46,8 @@ export type ParsedMessage =
 
 export type MessageFormat = 'JSON5' | 'YAML' | 'TOML';
 
+type MessageType = Record<string, ChromeMessage> | Record<number | 'n', string>;
+
 //
 // CONSTANTS
 //
@@ -94,7 +96,7 @@ const EXT_FORMATS_MAP: Record<string, MessageFormat> = {
   '.toml': 'TOML',
 };
 
-const PARSERS: Record<MessageFormat, (text: string) => any> = {
+const PARSERS: Record<MessageFormat, (text: string) => MessageType> = {
   YAML: parseYAML,
   JSON5: parseJSON5,
   TOML: parseTOML,
@@ -118,6 +120,7 @@ export async function parseMessagesFile(
 ): Promise<ParsedMessage[]> {
   const text = await readFile(file, 'utf8');
   const ext = extname(file).toLowerCase();
+
   return parseMessagesText(text, EXT_FORMATS_MAP[ext] ?? 'JSON5');
 }
 
@@ -134,7 +137,7 @@ export function parseMessagesText(
 /**
  * Given the JS object form of a raw messages file, extract the messages.
  */
-export function parseMessagesObject(object: any): ParsedMessage[] {
+export function parseMessagesObject(object: MessageType): ParsedMessage[] {
   return _parseMessagesObject(
     [],
     {
@@ -147,7 +150,7 @@ export function parseMessagesObject(object: any): ParsedMessage[] {
 
 function _parseMessagesObject(
   path: string[],
-  object: any,
+  object: MessageType,
   depth: number,
 ): ParsedMessage[] {
   switch (typeof object) {
@@ -168,54 +171,61 @@ function _parseMessagesObject(
       ];
     }
     case 'object':
-      if ([null, undefined].includes(object)) {
+      if (object === null || object === undefined) {
         throw new Error(
           `Messages file should not contain \`${object}\` (found at "${path.join('.')}")`,
         );
       }
+
       if (Array.isArray(object))
         return object.flatMap((item, i) =>
           _parseMessagesObject(path.concat(String(i)), item, depth + 1),
         );
+
       if (isPluralMessage(object)) {
         const message = Object.values(object).join('|');
         const substitutions = getSubstitutionCount(message);
+
         return [
           {
             type: 'plural',
             key: path,
             substitutions,
-            plurals: object,
+            plurals: object as Record<string, string>,
           },
         ];
       }
+
       if (depth === 1 && isChromeMessage(object)) {
-        const message = applyChromeMessagePlaceholders(object);
+        const message = applyChromeMessagePlaceholders(
+          object as unknown as ChromeMessage,
+        );
         const substitutions = getSubstitutionCount(message);
+
         return [
           {
             type: 'chrome',
             key: path,
             substitutions,
-            ...object,
+            ...(object as unknown as ChromeMessage),
           },
         ];
       }
       return Object.entries(object).flatMap(([key, value]) =>
-        _parseMessagesObject(path.concat(key), value, depth + 1),
+        _parseMessagesObject(path.concat(key), value as MessageType, depth + 1),
       );
     default:
       throw Error(`"Could not parse object of type "${typeof object}"`);
   }
 }
 
-function isPluralMessage(object: any): object is Record<number | 'n', string> {
+function isPluralMessage(object: MessageType) {
   return Object.keys(object).every(
     (key) => key === 'n' || isFinite(Number(key)),
   );
 }
 
-function isChromeMessage(object: any): object is ChromeMessage {
+function isChromeMessage(object: MessageType) {
   return Object.keys(object).every((key) =>
     ALLOWED_CHROME_MESSAGE_KEYS.has(key),
   );
@@ -227,7 +237,7 @@ function isChromeMessage(object: any): object is ChromeMessage {
 
 export function generateTypeText(messages: ParsedMessage[]): string {
   const renderMessageEntry = (message: ParsedMessage): string => {
-    // Use . for deep keys at runtime and types
+    // Use '.' for deep keys at runtime and types
     const key = message.key.join('.');
 
     const features = [

packages/i18n/src/index.ts

@@ -1,18 +1,11 @@
 /**
  * @module @wxt-dev/i18n
  */
-import {
-  I18nStructure,
-  DefaultI18nStructure,
-  I18n,
-  Substitution,
-} from './types';
+import { I18nStructure, I18n, Substitution } 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<T extends I18nStructure>(): I18n<T> {
+  const t = ((key, ...args) => {
     // Resolve args
     let sub: Substitution[] | undefined;
     let count: number | undefined;
@@ -64,7 +57,7 @@ export function createI18n<
       default:
         throw Error('Unknown plural formatting');
     }
-  };
+  }) as I18n<T>['t'];
 
-  return { t } as I18n<T>;
+  return { t };
 }

packages/i18n/src/types.ts

@@ -7,13 +7,23 @@ export type I18nStructure = {
   [K: string]: I18nFeatures;
 };
 
-export type DefaultI18nStructure = {
-  [K: string]: any;
+type DefaultTFunction<TKeys extends string> = {
+  (key: TKeys): string;
+  (key: TKeys, substitutions?: string[]): string;
+  (key: TKeys, n: number): string;
+  (key: TKeys, n: number, substitutions?: string[]): string;
 };
 
+export interface I18n<T extends I18nStructure> {
+  t: T extends I18nStructure
+    ? DefaultTFunction<keyof T & string>
+    : TFunction<Extract<T, I18nStructure>>;
+}
+
 // prettier-ignore
 export type SubstitutionTuple<T extends SubstitutionCount> =
-    T extends 1 ? [$1: Substitution]
+    T extends 0 ? []
+  : T extends 1 ? [$1: Substitution]
   : T extends 2 ? [$1: Substitution, $2: Substitution]
   : T extends 3 ? [$1: Substitution, $2: Substitution, $3: Substitution]
   : T extends 4 ? [$1: Substitution, $2: Substitution, $3: Substitution, $4: Substitution]
@@ -22,7 +32,7 @@ export type SubstitutionTuple<T extends SubstitutionCount> =
   : T extends 7 ? [$1: Substitution, $2: Substitution, $3: Substitution, $4: Substitution, $5: Substitution, $6: Substitution, $7: Substitution]
   : T extends 8 ? [$1: Substitution, $2: Substitution, $3: Substitution, $4: Substitution, $5: Substitution, $6: Substitution, $7: Substitution, $8: Substitution]
   : T extends 9 ? [$1: Substitution, $2: Substitution, $3: Substitution, $4: Substitution, $5: Substitution, $6: Substitution, $7: Substitution, $8: Substitution, $9: Substitution]
-  : never
+  : []
 
 export type TFunction<T extends I18nStructure> = {
   // Non-plural, no substitutions
@@ -31,7 +41,7 @@ export type TFunction<T extends I18nStructure> = {
     key: K & { [P in keyof T]: T[P] extends { plural: false; substitutions: 0 } ? P : never; }[keyof T],
   ): string;
 
-  // Non-plural with substitutions
+  // Non-plural with optional substitutions
   <K extends keyof T>(
     // prettier-ignore
     key: K & { [P in keyof T]: T[P] extends { plural: false; substitutions: SubstitutionCount } ? P : never; }[keyof T],
@@ -66,10 +76,6 @@ 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;