test: 💍 add tests for invalid ICU syntax

src/runtime/stores/formatters.ts

@@ -72,10 +72,7 @@ const formatMessage: MessageFormatter = (id, options = {}) => {
   try {
     result = getMessageFormatter(message, locale).format(values) as string;
   } catch (e) {
-    console.warn(
+    console.warn(`[svelte-i18n] Message "${id}" has syntax error:`, e.message);
-      `[svelte-i18n] Message with "${id}" has syntax error:`,
-      e.message,
-    );
   }
 
   return result;
@@ -93,7 +90,10 @@ const formatNumber: NumberFormatter = (n, options) => {
   return getNumberFormatter(options).format(n);
 };
 
-const getJSON: JSONGetter = <T = any>(id: string, locale = getCurrentLocale()) => {
+const getJSON: JSONGetter = <T = any>(
+  id: string,
+  locale = getCurrentLocale(),
+) => {
   return lookup(id, locale) as T;
 };
 

test/fixtures/en.json

@@ -5,5 +5,6 @@
   },
   "photos": "You have {n, plural, =0 {no photos.} =1 {one photo.} other {# photos.}}",
   "title": "Page title",
-  "sneakers": "sneakers"
+  "sneakers": "sneakers",
+  "with-syntax-error": "Hello {{name}}!"
 }

test/runtime/stores/formatters.test.ts

@@ -106,30 +106,43 @@ describe('format message', () => {
   });
 
   it('errors out when value found is not string', () => {
-    const { warn } = global.console;
+    const spy = jest.spyOn(global.console, 'warn').mockImplementation();
-
-    jest.spyOn(global.console, 'warn').mockImplementation();
 
     expect(typeof formatMessage('form')).toBe('object');
-    expect(console.warn).toBeCalledWith(
+    expect(spy).toBeCalledWith(
       `[svelte-i18n] Message with id "form" must be of type "string", found: "object". Gettin its value through the "$format" method is deprecated; use the "json" method instead.`,
     );
 
-    global.console.warn = warn;
+    spy.mockRestore();
   });
 
   it('warn on missing messages', () => {
-    const { warn } = global.console;
+    const spy = jest.spyOn(global.console, 'warn').mockImplementation();
-
-    jest.spyOn(global.console, 'warn').mockImplementation();
 
     formatMessage('missing');
 
-    expect(console.warn).toBeCalledWith(
+    expect(spy).toBeCalledWith(
       `[svelte-i18n] The message "missing" was not found in "en".`,
     );
 
-    global.console.warn = warn;
+    spy.mockRestore();
+  });
+
+  it('does not throw with invalid syntax', () => {
+    $locale.set('en');
+    const spy = jest.spyOn(global.console, 'warn').mockImplementation();
+
+    // eslint-disable-next-line line-comment-position
+    formatMessage('with-syntax-error', { values: { name: 'John' } });
+
+    expect(spy).toHaveBeenCalledWith(
+      expect.stringContaining(
+        `[svelte-i18n] Message "with-syntax-error" has syntax error:`,
+      ),
+      expect.anything(),
+    );
+
+    spy.mockRestore();
   });
 });