Add `Message` descriptor functions

js/modules/types/message.js

@@ -1,11 +1,37 @@
 const Attachment = require('./attachment');
 
-exports.GROUP = 'group';
-exports.PRIVATE = 'private';
 
+const GROUP = 'group';
+const PRIVATE = 'private';
+
+// Public API
+exports.GROUP = GROUP;
+exports.PRIVATE = PRIVATE;
+
+// Schema
 // Message -> Promise Message
 exports.upgradeSchema = async message =>
   Object.assign({}, message, {
     attachments:
       await Promise.all(message.attachments.map(Attachment.upgradeSchema)),
   });
+
+// Descriptors
+exports.getGroupDescriptor = group => ({
+  type: GROUP,
+  id: group.id,
+});
+
+// Matches data from `libtextsecure` `MessageReceiver::handleSentMessage`:
+exports.getDescriptorForSent = ({ message, destination }) => (
+  message.group
+    ? exports.getGroupDescriptor(message.group)
+    : { type: PRIVATE, id: destination }
+);
+
+// Matches data from `libtextsecure` `MessageReceiver::handleDataMessage`:
+exports.getDescriptorForReceived = ({ message, source }) => (
+  message.group
+    ? exports.getGroupDescriptor(message.group)
+    : { type: PRIVATE, id: source }
+);

test/modules/types/message_test.js

@@ -0,0 +1,95 @@
+const { assert } = require('chai');
+
+const Message = require('../../../js/modules/types/message');
+
+
+describe('Message', () => {
+  describe('getGroupDescriptor', () => {
+    it('should return valid descriptor`', () => {
+      const group = {
+        id: '+10000000000',
+      };
+      const expected = {
+        type: 'group',
+        id: '+10000000000',
+      };
+      assert.deepEqual(Message.getGroupDescriptor(group), expected);
+    });
+  });
+
+  describe('getDescriptorForSent', () => {
+    context('for private messages', () => {
+      it('should return valid descriptor`', () => {
+        const data = {
+          message: {
+            id: '+10000000000',
+          },
+          destination: '+10000000000',
+        };
+
+        const expected = {
+          type: 'private',
+          id: '+10000000000',
+        };
+
+        assert.deepEqual(Message.getDescriptorForSent(data), expected);
+      });
+    });
+    context('for group messages', () => {
+      it('should return valid descriptor`', () => {
+        const data = {
+          message: {
+            group: {
+              id: '+10000000000',
+            },
+          },
+        };
+
+        const expected = {
+          type: 'group',
+          id: '+10000000000',
+        };
+
+        assert.deepEqual(Message.getDescriptorForSent(data), expected);
+      });
+    });
+  });
+
+  describe('getDescriptorForReceived', () => {
+    context('for private messages', () => {
+      it('should return valid descriptor`', () => {
+        const data = {
+          message: {
+            id: '+10000000000',
+          },
+          source: '+10000000000',
+        };
+
+        const expected = {
+          type: 'private',
+          id: '+10000000000',
+        };
+
+        assert.deepEqual(Message.getDescriptorForReceived(data), expected);
+      });
+    });
+    context('for group messages', () => {
+      it('should return valid descriptor`', () => {
+        const data = {
+          message: {
+            group: {
+              id: '+10000000000',
+            },
+          },
+        };
+
+        const expected = {
+          type: 'group',
+          id: '+10000000000',
+        };
+
+        assert.deepEqual(Message.getDescriptorForReceived(data), expected);
+      });
+    });
+  });
+});