build-type: fix when is missing the variables on a message

Author: macabeus

example/assets/locales/pt-br/translations.ftl.d.ts

@@ -15,7 +15,7 @@ type Message<T> = {
 declare global {
   interface FluentBundleTyped extends FluentBundle {
     getMessage<T extends MessagesKey>(id: T): Message<T>
-    formatPattern<T extends MessagesKey>(pattern: Pattern<T>, args?: PatternArguments<T>, errors?: Array<Error> | null): string
+    formatPattern: <T extends MessagesKey>(pattern: Pattern<T>, ...args: PatternArguments<T>) => string
   }
 }
 
@@ -24,10 +24,10 @@ type MessagesKey = 'hello' |
 'bye'
 type PatternArguments<T extends MessagesKey> = (
   T extends 'hello'
-  ? { 'name': string | number }:
+  ? [{ 'name': string | number }]:
 T extends 'how-are-you'
-  ? undefined:
+  ? []:
 T extends 'bye'
-  ? undefined
+  ? []
   : never
 )

src/build-header.js

@@ -19,7 +19,7 @@ const header = dedent`
   declare global {
     interface FluentBundleTyped extends FluentBundle {
       getMessage<T extends MessagesKey>(id: T): Message<T>
-      formatPattern<T extends MessagesKey>(pattern: Pattern<T>, args?: PatternArguments<T>, errors?: Array<Error> | null): string
+      formatPattern: <T extends MessagesKey>(pattern: Pattern<T>, ...args: PatternArguments<T>) => string
     }
   }
 `

src/build-type-pattern-arguments.js

@@ -27,13 +27,13 @@ const buildTypePatternArguments = (resource) => {
       if (hasVariables(variables)) {
         return dedent`
           T extends '${message.id}'
-            ? { ${wrapVariables(messageVariables(message)).join(',')} }
+            ? [{ ${wrapVariables(messageVariables(message)).join(',')} }]
         `
       }
 
       return dedent`
         T extends '${message.id}'
-          ? undefined
+          ? []
       `
     }).join(':\n')
 

test/index.test.js

@@ -28,7 +28,7 @@ test('Should match the types definitions', async () => {
     declare global {
       interface FluentBundleTyped extends FluentBundle {
         getMessage<T extends MessagesKey>(id: T): Message<T>
-        formatPattern<T extends MessagesKey>(pattern: Pattern<T>, args?: PatternArguments<T>, errors?: Array<Error> | null): string
+        formatPattern: <T extends MessagesKey>(pattern: Pattern<T>, ...args: PatternArguments<T>) => string
       }
     }
 
@@ -37,11 +37,11 @@ test('Should match the types definitions', async () => {
     'bye'
     type PatternArguments<T extends MessagesKey> = (
       T extends 'hello'
-      ? { 'name': string | number }:
+      ? [{ 'name': string | number }]:
     T extends 'how-are-you'
-      ? undefined:
+      ? []:
     T extends 'bye'
-      ? undefined
+      ? []
       : never
     )
   `)