Added tests for RepositoryUniqueChecker

ghost/collections/test/RepositoryUniqueChecker.test.ts

@@ -0,0 +1,31 @@
+import assert from 'assert/strict';
+import {CollectionsRepositoryInMemory} from '../src/CollectionsRepositoryInMemory';
+import {Collection} from '../src/Collection';
+import {RepositoryUniqueChecker} from '../src/RepositoryUniqueChecker';
+
+describe('RepositoryUniqueChecker', function () {
+    let uniqueChecker: RepositoryUniqueChecker;
+
+    beforeEach(async function () {
+        const repository = new CollectionsRepositoryInMemory();
+        const collection = await Collection.create({
+            title: 'Test',
+            slug: 'not-unique'
+        });
+        repository.save(collection);
+        uniqueChecker = new RepositoryUniqueChecker(repository);
+    });
+    it('should return true if slug is unique', async function () {
+        const actual = await uniqueChecker.isUniqueSlug('unique');
+        const expected = true;
+
+        assert.equal(actual, expected, 'The slug "unique" should be unique');
+    });
+
+    it('should return false if slug is not unique', async function () {
+        const actual = await uniqueChecker.isUniqueSlug('not-unique');
+        const expected = false;
+
+        assert.equal(actual, expected, 'The slug "not-unique" should not be unique');
+    });
+});