feat: 🎸 add $json method to get raw dicitonary values

✅ Closes: #109, #83

docs/Formatting.md

@@ -3,10 +3,11 @@
 <!-- code_chunk_output -->
 
 - [Message syntax](#message-syntax)
-- [`$format` or `$_` or `$t`](#format-or-_-or-t)
+- [`$format`, `$_` or `$t`](#format-_-or-t)
 - [`$time(number: Date, options: MessageObject)`](#timenumber-date-options-messageobject)
 - [`$date(date: Date, options: MessageObject)`](#datedate-date-options-messageobject)
 - [`$number(number: number, options: MessageObject)`](#numbernumber-number-options-messageobject)
+- [`$json(messageId: string)`](#jsonmessageid-string)
 - [Formats](#formats)
 - [Accessing formatters directly](#accessing-formatters-directly)
 
@@ -20,7 +21,7 @@ Under the hood, `formatjs` is used for localizing your messages. It allows `svel
 - [Runtime Environments](https://formatjs.io/docs/guides/runtime-requirements/)
 - [ICU Message Syntax](https://formatjs.io/docs/core-concepts/icu-syntax/)
 
-### `$format` or `$_` or `$t`
+### `$format`, `$_` or `$t`
 
 `import { _, t, format } from 'svelte-i18n'`
 
@@ -41,11 +42,11 @@ The formatter can be called with two different signatures:
 
 ```ts
 interface MessageObject {
-  id?: string
-  locale?: string
-  format?: string
-  default?: string
-  values?: Record<string, string | number | Date>
+  id?: string;
+  locale?: string;
+  format?: string;
+  default?: string;
+  values?: Record<string, string | number | Date>;
 }
 ```
 
@@ -56,6 +57,7 @@ interface MessageObject {
 - `values`: properties that should be interpolated in the message;
 
 You can pass a `string` as the first parameter for a less verbose way of formatting a message. It is also possible to inject values into the translation like so:
+
 ```jsonc
 // en.json
 {
@@ -126,6 +128,30 @@ Formats a number with the specified locale and format. Please refer to the [#for
 <!-- 100.000.000 -->
 ```
 
+### `$json(messageId: string)`
+
+`import { json } from 'svelte-i18n'`
+
+Returns the raw JSON value of the specified `messageId` for the current locale. While [`$format`](#format-_-or-t) always returns a string, `$json` can be used to get an object relative to the current locale.
+
+```html
+<ul>
+  {#each $json('list.items') as item}
+    <li>{item.name}</li>
+  {/each}
+</ul>
+```
+
+If you're using TypeScript, you can define the returned type as well:
+
+```html
+<ul>
+  {#each $json<Item[]>('list.items') as item}
+    <li>{item.name}</li>
+  {/each}
+</ul>
+```
+
 ### Formats
 
 `svelte-i18n` comes with a default set of `number`, `time` and `date` formats:
@@ -163,24 +189,24 @@ import {
   getNumberFormatter,
   getTimeFormatter,
   getMessageFormatter,
-} from 'svelte-i18n'
+} from 'svelte-i18n';
 ```
 
 By using these methods, it's possible to manipulate values in a more specific way that fits your needs. For example, it's possible to create a method which receives a `date` and returns its relevant date related parts:
 
 ```js
-import { getDateFormatter } from 'svelte-i18n'
+import { getDateFormatter } from 'svelte-i18n';
 
-const getDateParts = date =>
+const getDateParts = (date) =>
   getDateFormatter()
     .formatToParts(date)
     .filter(({ type }) => type !== 'literal')
     .reduce((acc, { type, value }) => {
-      acc[type] = value
-      return acc
-    }, {})
+      acc[type] = value;
+      return acc;
+    }, {});
 
-getDateParts(new Date(2020, 0, 1)) // { month: '1', day: '1', year: '2020' }
+getDateParts(new Date(2020, 0, 1)); // { month: '1', day: '1', year: '2020' }
 ```
 
 Check the [methods documentation](/docs/Methods.md#low-level-api) for more information.

src/runtime/includes/lookup.ts

@@ -1,7 +1,11 @@
 import { getMessageFromDictionary } from '../stores/dictionary';
 import { getFallbackOf } from '../stores/locale';
 
-export const lookupCache: Record<string, Record<string, string>> = {};
+export const lookupCache: {
+  [locale: string]: {
+    [messageId: string]: any;
+  };
+} = {};
 
 const addToCache = (path: string, locale: string, message: string) => {
   if (!message) return message;
@@ -11,8 +15,8 @@ const addToCache = (path: string, locale: string, message: string) => {
   return message;
 };
 
-const searchForMessage = (path: string, locale: string): string => {
-  if (locale == null) return null;
+const searchForMessage = (path: string, locale: string): any => {
+  if (locale == null) return undefined;
 
   const message = getMessageFromDictionary(locale, path);
 
@@ -32,5 +36,5 @@ export const lookup = (path: string, locale: string) => {
     return addToCache(path, locale, message);
   }
 
-  return null;
+  return undefined;
 };

src/runtime/index.ts

@@ -33,6 +33,7 @@ export { registerLocaleLoader as register } from './includes/loaderQueue';
 export { $isLoading as isLoading } from './stores/loading';
 
 export {
+  $json as json,
   $format as format,
   $format as _,
   $format as t,

src/runtime/stores/formatters.ts

@@ -6,6 +6,7 @@ import {
   TimeFormatter,
   DateFormatter,
   NumberFormatter,
+  JSONGetter,
 } from '../types';
 import { lookup } from '../includes/lookup';
 import { hasLocaleQueue } from '../includes/loaderQueue';
@@ -54,23 +55,39 @@ const formatMessage: MessageFormatter = (id, options = {}) => {
     }
 
     message = defaultValue || id;
+  } else if (typeof message !== 'string') {
+    console.error(
+      `[svelte-i18n] Message with id "${id}" must be of type "string", found: "${typeof message}". Gettin its value through the "$format" method is deprecated; use the "json" method instead.`,
+    );
+
+    return message;
   }
 
-  if (!values) return message;
+  if (!values) {
+    return message;
+  }
 
   return getMessageFormatter(message, locale).format(values) as string;
 };
 
-const formatTime: TimeFormatter = (t, options) =>
-  getTimeFormatter(options).format(t);
+const formatTime: TimeFormatter = (t, options) => {
+  return getTimeFormatter(options).format(t);
+};
+
+const formatDate: DateFormatter = (d, options) => {
+  return getDateFormatter(options).format(d);
+};
 
-const formatDate: DateFormatter = (d, options) =>
-  getDateFormatter(options).format(d);
+const formatNumber: NumberFormatter = (n, options) => {
+  return getNumberFormatter(options).format(n);
+};
 
-const formatNumber: NumberFormatter = (n, options) =>
-  getNumberFormatter(options).format(n);
+const getJSON: JSONGetter = <T>(id: string, locale = getCurrentLocale()) => {
+  return lookup(id, locale) as T;
+};
 
 export const $format = derived([$locale, $dictionary], () => formatMessage);
 export const $formatTime = derived([$locale], () => formatTime);
 export const $formatDate = derived([$locale], () => formatDate);
 export const $formatNumber = derived([$locale], () => formatNumber);
+export const $json = derived([$locale, $dictionary], () => getJSON);

src/runtime/types/index.ts

@@ -49,6 +49,8 @@ export type NumberFormatter = (
   options?: IntlFormatterOptions<Intl.NumberFormatOptions>,
 ) => string;
 
+export type JSONGetter = <T extends any>(id: string, locale?: string) => T;
+
 type IntlFormatterOptions<T> = T & {
   format?: string;
   locale?: string;

test/runtime/includes/lookup.test.ts

@@ -9,8 +9,8 @@ beforeEach(() => {
 });
 
 test('returns null if no locale was passed', () => {
-  expect(lookup('message.id', undefined)).toBeNull();
-  expect(lookup('message.id', null)).toBeNull();
+  expect(lookup('message.id', undefined)).toBeUndefined();
+  expect(lookup('message.id', null)).toBeUndefined();
 });
 
 test('gets a shallow message of a locale dictionary', () => {
@@ -61,6 +61,7 @@ test('gets an array ', () => {
 test('caches found messages by locale', () => {
   addMessages('en', { field: 'name' });
   addMessages('pt', { field: 'nome' });
+
   lookup('field', 'en-US');
   lookup('field', 'pt');
 
@@ -73,8 +74,10 @@ test('caches found messages by locale', () => {
 test("doesn't cache falsy messages", () => {
   addMessages('en', { field: 'name' });
   addMessages('pt', { field: 'nome' });
+
   lookup('field_2', 'en-US');
   lookup('field_2', 'pt');
+
   expect(lookupCache).not.toMatchObject({
     'en-US': { field_2: 'name' },
     pt: { field_2: 'nome' },