Merge pull request #7 from sveyret/bettertyping

Improve typings

package.json

@@ -1,6 +1,6 @@
 {
   "name": "intl-ts",
-  "version": "4.0.1",
+  "version": "4.0.2",
   "description": "Internationalization library for TypeScript",
   "main": "dist/index.js",
   "typings": "dist/index.d.ts",
@@ -47,6 +47,8 @@
   "keywords": [
     "internationalization",
     "internationalisation",
+    "localization",
+    "localisation",
     "intl",
     "i18n",
     "library",

src/Intl.ts

@@ -1,5 +1,5 @@
 import { LanguageMap } from './LanguageMap'
-import { MessageFunction, Messages, PartialMessages } from './Messages'
+import { MessageFunction, Messages, PartialMessages } from './MessageTypes'
 
 /**
  * The default functions and data for the Intl object.
@@ -81,7 +81,7 @@ function calculatePreferences(
 }
 
 /*
- * Try to load the `mobx` library. If succeeded, will give the ability to create observable properties.
+ * Try to load the `mobx` library. If succeed, will give the ability to create observable properties.
  */
 let mobx: typeof import('mobx') | undefined
 try {
@@ -186,7 +186,7 @@ Intl.prototype.$getMessageFunction = function<T extends Messages, K extends keyo
   for (const preference of this.$preferences) {
     const language: Readonly<PartialMessages<T>> = this.$languageMap.messages(preference)
     if (name in language) {
-      message = language[name] as T[K]
+      message = (language as T)[name]
       break
     }
   }

src/LanguageMap.spec.ts

@@ -2,7 +2,7 @@
 import { expect } from 'chai'
 
 import { LanguageMap } from '.'
-import { PartialMessages } from './Messages'
+import { PartialMessages } from './MessageTypes'
 
 // English version — default
 export const en = {

src/LanguageMap.ts

@@ -1,12 +1,11 @@
-import { Messages, PartialMessages } from './Messages'
+import { Messages, PartialMessages } from './MessageTypes'
 
 /**
  * Definition of a language map (the object containing messages for each languages).
  */
-export interface LanguageMapDefinition<T extends Messages> {
+export type LanguageMapDefinition<T extends Messages> = {
   default: T
-  [lang: string]: PartialMessages<T> | 'default'
-}
+} & Omit<{ [lang: string]: PartialMessages<T> | 'default' }, 'default'>
 
 /**
  * The language map contains a list of messages for each supported language. A LanguageMap is immutable.

src/MessageTypes.ts

@@ -0,0 +1,23 @@
+/**
+ * A simple message may be either directly a string or a function.
+ */
+export type Message = string | ((...args: any[]) => string)
+
+/**
+ * A message converted into a function.
+ */
+export type MessageFunction<T extends Message> = T extends string ? () => string : T
+
+/**
+ * The available messages for a given language.
+ */
+export type Messages = {
+  $: string // The language name itself
+} & Omit<{ [key: string]: Message }, '$'>
+
+/**
+ * The available messages for a given language.
+ */
+export type PartialMessages<T extends Messages> = {
+  $: string
+} & Partial<Omit<T, '$'>>

src/index.ts

@@ -1,3 +1,3 @@
-export { Messages, PartialMessages } from './Messages'
+export { Message, Messages, PartialMessages } from './MessageTypes'
 export { LanguageMapDefinition, LanguageMap } from './LanguageMap'
 export { Intl as default } from './Intl'