Don't show name collisions for system contacts

ts/test-both/util/isInSystemContacts_test.ts

@@ -0,0 +1,46 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+
+import { isInSystemContacts } from '../../util/isInSystemContacts';
+
+describe('isInSystemContacts', () => {
+  it('returns true for direct conversations that have a `name` property', () => {
+    assert.isTrue(
+      isInSystemContacts({
+        type: 'direct',
+        name: 'Jane Doe',
+      })
+    );
+    assert.isTrue(
+      isInSystemContacts({
+        type: 'private',
+        name: 'Jane Doe',
+      })
+    );
+  });
+
+  it('returns true for direct conversations that have an empty string `name`', () => {
+    assert.isTrue(
+      isInSystemContacts({
+        type: 'direct',
+        name: '',
+      })
+    );
+  });
+
+  it('returns false for direct conversations that lack a `name` property', () => {
+    assert.isFalse(isInSystemContacts({ type: 'direct' }));
+  });
+
+  it('returns false for group conversations', () => {
+    assert.isFalse(isInSystemContacts({ type: 'group' }));
+    assert.isFalse(
+      isInSystemContacts({
+        type: 'group',
+        name: 'Tahoe Trip',
+      })
+    );
+  });
+});