fix(academic): детерминированный предпросмотр при совпадении slug

services/academic-service/src/main/kotlin/ru/ysu/lms/academic/content/ContentService.kt

@@ -148,10 +148,12 @@ class ContentService(
         sectionSlug: String,
         articleSlug: String,
     ): ContentArticleView {
-        // Сначала глобальная глава: findBySlug может упасть на коллизии slug между курсами.
+        // Сначала глобальная глава, затем первая курсовая по id: slug может повторяться
+        // в разных курсах, а findBySlug на дублях бросает IncorrectResultSizeDataAccessException.
         val ch =
             requireFound(
-                chapters.findBySlugAndCourseIdIsNull(chapterSlug) ?: chapters.findBySlug(chapterSlug),
+                chapters.findBySlugAndCourseIdIsNull(chapterSlug)
+                    ?: chapters.findFirstBySlugOrderByIdAsc(chapterSlug),
                 "Глава не найдена",
             )
         return articleView(ch, sectionSlug, articleSlug, includeHidden = true)

services/academic-service/src/main/kotlin/ru/ysu/lms/academic/repo/ContentRepositories.kt

@@ -11,6 +11,8 @@ interface ContentChapterRepository : JpaRepository<ContentChapter, UUID> {
 
     fun findBySlug(slug: String): ContentChapter?
 
+    fun findFirstBySlugOrderByIdAsc(slug: String): ContentChapter?
+
     fun findBySlugAndCourseIdIsNull(slug: String): ContentChapter?
 
     fun findByCourseIdOrderByPositionAscIdAsc(courseId: UUID): List<ContentChapter>

services/academic-service/src/test/kotlin/ru/ysu/lms/academic/content/CourseContentIntegrationTest.kt

@@ -56,6 +56,9 @@ class CourseContentIntegrationTest {
         fun assetsDir(registry: DynamicPropertyRegistry) {
             registry.add("lms.content.assets-dir") { Files.createTempDirectory("lms-assets").toString() }
         }
+
+        private const val PREVIEW_SECTION_SLUG = "preview-section"
+        private const val PREVIEW_ARTICLE_SLUG = "preview-article"
     }
 
     @Autowired
@@ -248,6 +251,20 @@ class CourseContentIntegrationTest {
             .andExpect(status().isUnauthorized)
     }
 
+    @Test
+    fun `admin preview resolves same-slug course chapters deterministically`() {
+        val sharedSlug = "shared-${UUID.randomUUID()}"
+        val first = seedChapter(title = "Первая курсовая", courseId = newCourse().id, audience = null, slug = sharedSlug)
+        val second = seedChapter(title = "Вторая курсовая", courseId = newCourse().id, audience = null, slug = sharedSlug)
+        val firstArticle = seedPreviewArticle(first, "Статья первой главы")
+        val secondArticle = seedPreviewArticle(second, "Статья второй главы")
+        val expectedTitle = if (first.id < second.id) firstArticle.title else secondArticle.title
+
+        val view = contentService.findArticleForAdmin(sharedSlug, PREVIEW_SECTION_SLUG, PREVIEW_ARTICLE_SLUG)
+
+        assertThat(view.title).isEqualTo(expectedTitle)
+    }
+
     private fun newCourse(): TestCourse {
         val detail =
             courseService.create(
@@ -262,11 +279,12 @@ class CourseContentIntegrationTest {
         courseId: UUID?,
         audience: String?,
         published: Boolean = true,
+        slug: String = "chapter-${UUID.randomUUID()}",
     ): ContentChapter =
         chapters.saveAndFlush(
             ContentChapter(
                 title = title,
-                slug = "chapter-${UUID.randomUUID()}",
+                slug = slug,
                 position = 1,
                 published = published,
                 courseId = courseId,
@@ -274,6 +292,30 @@ class CourseContentIntegrationTest {
             ),
         )
 
+    private fun seedPreviewArticle(
+        chapter: ContentChapter,
+        title: String,
+    ): ContentArticle {
+        val section =
+            sections.saveAndFlush(
+                ContentSection(
+                    chapterId = chapter.id,
+                    title = "Раздел",
+                    slug = PREVIEW_SECTION_SLUG,
+                    position = 1,
+                ),
+            )
+        return articles.saveAndFlush(
+            ContentArticle(
+                sectionId = section.id,
+                title = title,
+                slug = PREVIEW_ARTICLE_SLUG,
+                bodyMd = "Текст",
+                position = 1,
+            ),
+        )
+    }
+
     private fun seedMaterial(
         courseId: UUID?,
         published: Boolean,