feat(resource): inherit unspecified message lang, dir, and dnt

GETTING_STARTED.md

@@ -70,6 +70,9 @@ Set `format` to `'MF1'`, `'MF2'`, or `'NONE'` on a project, resource, or
 message. It is a TypeScript union type (there is no enum), and lower levels
 inherit from higher levels unless they override it.
 
+Message `lang`, `dir`, and `dnt` also inherit from the resource when omitted
+(including in compact translation JSON). An explicit per-message value wins.
+
 ```typescript
 // MF1 syntax (ICU MessageFormat 1)
 resource.add('files', '{count, plural, one {# file} other {# files}}', { format: 'MF1' });

README.md

@@ -159,6 +159,8 @@ Every message is formatted according to its resolved `format` attribute:
 
 The `format` is inheritable: a resource inherits its project's `format` unless it sets its own, and a message inherits its resource's `format` unless it sets its own. The default is `MF2`, so existing code keeps working unchanged. Use a TypeScript union (`'MF1' | 'MF2' | 'NONE'`) — there is no enum.
 
+`lang`, `dir`, and `dnt` inherit the same way on messages: omitted fields (or omitted `attributes`) take the resource's values, and an explicit per-message value still wins. Compact translation JSON can therefore list only overrides. `create()`, `add()`, `translate()`, and `getTranslation()` all apply this merge.
+
 The following is a **separate illustration** of format inheritance and per-message overrides (not the CLI `Main` / `Messages` scaffold above):
 
 ```typescript

src/classes/MsgResource/MsgResource.ts

@@ -149,6 +149,9 @@ export class MsgResource extends Map<string, MsgMessage> implements MsgInterface
   /**
    * Adds a message to this resource, merging resource attributes with any overrides.
    *
+   * Unspecified `lang`, `dir`, and `dnt` inherit from this resource; explicit
+   * values on the message win.
+   *
    * @returns This resource, for chaining.
    */
   public add(key: string, value: string, attributes?: MsgAttributes, notes?: MsgNote[]) {
@@ -169,7 +172,8 @@ export class MsgResource extends Map<string, MsgMessage> implements MsgInterface
    * Builds a translated copy of this resource from translation data.
    *
    * Messages present in the translation replace the source; missing keys keep
-   * the source message. Notes are carried over from the source.
+   * the source message. Notes are carried over from the source. Unspecified
+   * message `lang`, `dir`, and `dnt` inherit from the translated resource.
    *
    * @throws {TypeError} When the translation title does not match this resource.
    */
@@ -194,17 +198,16 @@ export class MsgResource extends Map<string, MsgMessage> implements MsgInterface
 
     messages?.forEach(messageData => {
       const {key, value, attributes} = messageData;
-      const msg = MsgMessage.create({
+      const source = this.get(key);
+      // Inherit lang/dir/dnt from the translated resource (same merge as add()),
+      // while still preserving the source message's format when the translation
+      // does not set one.
+      translated.add(
         key,
         value,
-        // preserve the source message's format unless the translation overrides it
-        attributes: this.preserveFormat(attributes, this.get(key)?.attributes.format),
-      });
-      const notes = this.get(key)?.notes || []; // transfer the notes
-      notes.forEach(note => {
-        msg.addNote(note.type, note.content);
-      })
-      translated.set(key, msg);
+        this.preserveFormat(attributes, source?.attributes.format),
+        source?.notes
+      );
     })
 
     return translated;

src/tests/MsgResource.test.ts

@@ -71,6 +71,37 @@ describe('MsgResource tests', () => {
     expect(resource.has('test-2')).toBe(true);
     expect(resource.get('test-1')?.value).toBe('This is test 1');
     expect(resource.get('test-2')?.value).toBe('This is test 2');
+    expect(resource.get('test-1')?.attributes.lang).toBe('en');
+    expect(resource.get('test-1')?.attributes.dir).toBe('ltr');
+    expect(resource.get('test-1')?.attributes.dnt).toBe(false);
+  });
+
+  test('MsgResource: "create" inherits unspecified message lang, dir, and dnt from the resource', () => {
+    const project = MsgProject.create(testProjectData);
+    const resource = MsgResource.create({
+      title: 'TestResource',
+      attributes: { lang: 'en', dir: 'rtl', dnt: true },
+      messages: [
+        { key: 'omitted', value: 'No attributes' },
+        { key: 'dnt-only', value: 'DNT override', attributes: { dnt: false } },
+        { key: 'lang-only', value: 'Lang override', attributes: { lang: 'fr' } }
+      ]
+    }, project);
+
+    const omitted = resource.get('omitted');
+    expect(omitted?.attributes.lang).toBe('en');
+    expect(omitted?.attributes.dir).toBe('rtl');
+    expect(omitted?.attributes.dnt).toBe(true);
+
+    const dntOnly = resource.get('dnt-only');
+    expect(dntOnly?.attributes.lang).toBe('en');
+    expect(dntOnly?.attributes.dir).toBe('rtl');
+    expect(dntOnly?.attributes.dnt).toBe(false);
+
+    const langOnly = resource.get('lang-only');
+    expect(langOnly?.attributes.lang).toBe('fr');
+    expect(langOnly?.attributes.dir).toBe('rtl');
+    expect(langOnly?.attributes.dnt).toBe(true);
   });
 
   test('MsgResource: "create" static method with notes', () => {
@@ -549,6 +580,44 @@ describe('MsgResource tests', () => {
     expect(msg?.attributes.dnt).toBe(true);
   });
 
+  test('MsgResource: "translate" inherits unspecified message lang, dir, and dnt from the translated resource', () => {
+    const project = MsgProject.create(testProjectData);
+    const original = MsgResource.create({
+      title: 'TestResource',
+      attributes: { lang: 'en', dir: 'ltr', dnt: false },
+      messages: [
+        { key: 'omitted', value: 'Original omitted' },
+        { key: 'dnt-only', value: 'Original dnt' },
+        { key: 'lang-only', value: 'Original lang' }
+      ]
+    }, project);
+
+    const translated = original.translate({
+      title: 'TestResource',
+      attributes: { lang: 'zh', dir: 'rtl', dnt: true },
+      messages: [
+        { key: 'omitted', value: '翻译 omitted' },
+        { key: 'dnt-only', value: '翻译 dnt', attributes: { dnt: false } },
+        { key: 'lang-only', value: '翻译 lang', attributes: { lang: 'fr' } }
+      ]
+    });
+
+    const omitted = translated.get('omitted');
+    expect(omitted?.attributes.lang).toBe('zh');
+    expect(omitted?.attributes.dir).toBe('rtl');
+    expect(omitted?.attributes.dnt).toBe(true);
+
+    const dntOnly = translated.get('dnt-only');
+    expect(dntOnly?.attributes.lang).toBe('zh');
+    expect(dntOnly?.attributes.dir).toBe('rtl');
+    expect(dntOnly?.attributes.dnt).toBe(false);
+
+    const langOnly = translated.get('lang-only');
+    expect(langOnly?.attributes.lang).toBe('fr');
+    expect(langOnly?.attributes.dir).toBe('rtl');
+    expect(langOnly?.attributes.dnt).toBe(true);
+  });
+
   test('MsgResource: "translate" method transfers notes to new messages', () => {
     const project = MsgProject.create(testProjectData);
     const original = MsgResource.create({
@@ -609,6 +678,50 @@ describe('MsgResource tests', () => {
     expect(translated.size).toBe(2);
     expect(translated.get('test-1')?.value).toBe('这是测试 1');
     expect(translated.get('test-2')?.value).toBe('这是测试 2');
+    expect(translated.get('test-1')?.attributes.lang).toBe('zh');
+    expect(translated.get('test-1')?.attributes.dir).toBe('ltr');
+    expect(translated.get('test-1')?.attributes.dnt).toBe(false);
+  });
+
+  test('MsgResource: "getTranslation" inherits unspecified message lang, dir, and dnt from the translated resource', async () => {
+    const project = MsgProject.create({
+      ...testProjectData,
+      loader: async () => ({
+        title: 'TestResource',
+        attributes: { lang: 'zh', dir: 'rtl', dnt: true },
+        messages: [
+          { key: 'omitted', value: '翻译 omitted' },
+          { key: 'dnt-only', value: '翻译 dnt', attributes: { dnt: false } },
+          { key: 'lang-only', value: '翻译 lang', attributes: { lang: 'fr' } }
+        ]
+      })
+    });
+    const resource = MsgResource.create({
+      title: 'TestResource',
+      attributes: { lang: 'en', dir: 'ltr', dnt: false },
+      messages: [
+        { key: 'omitted', value: 'Original omitted' },
+        { key: 'dnt-only', value: 'Original dnt' },
+        { key: 'lang-only', value: 'Original lang' }
+      ]
+    }, project);
+
+    const translated = await resource.getTranslation('zh');
+
+    const omitted = translated.get('omitted');
+    expect(omitted?.attributes.lang).toBe('zh');
+    expect(omitted?.attributes.dir).toBe('rtl');
+    expect(omitted?.attributes.dnt).toBe(true);
+
+    const dntOnly = translated.get('dnt-only');
+    expect(dntOnly?.attributes.lang).toBe('zh');
+    expect(dntOnly?.attributes.dir).toBe('rtl');
+    expect(dntOnly?.attributes.dnt).toBe(false);
+
+    const langOnly = translated.get('lang-only');
+    expect(langOnly?.attributes.lang).toBe('fr');
+    expect(langOnly?.attributes.dir).toBe('rtl');
+    expect(langOnly?.attributes.dnt).toBe(true);
   });
 
   test('MsgResource: "getTranslation" method without lang clones the resource', async () => {