feat: main branch for the existing keys, tasks, imports, language stats

backend/app/src/test/kotlin/io/tolgee/api/v2/controllers/AllKeysControllerTest.kt

@@ -36,15 +36,15 @@ class AllKeysControllerTest : ProjectAuthControllerTest("/v2/projects/") {
           node("id").isValidId
           node("namespace").isNull()
           node("name").isEqualTo("first_key")
-          node("branch").isNull()
+          node("branch").isEqualTo("main")
         }
         node("[1]") {
           node("name").isEqualTo("second_key")
-          node("branch").isNull()
+          node("branch").isEqualTo("main")
         }
         node("[2]") {
           node("name").isEqualTo("key_with_referecnces")
-          node("branch").isNull()
+          node("branch").isEqualTo("main")
         }
       }
     }

backend/app/src/test/kotlin/io/tolgee/api/v2/controllers/BigMetaControllerTest.kt

@@ -67,9 +67,9 @@ class BigMetaControllerTest :
     measureTime {
       storeAndAssertSize(keys, 0, 30, 354)
       storeAndAssertSize(keys, 500, 100, 1409)
-      storeAndAssertSize(keys, 10, 200, 3155)
-      storeAndAssertSize(keys, 800, 50, 3710)
-      storeAndAssertSize(keys, 800, 50, 3710)
+      storeAndAssertSize(keys, 10, 200, 3268)
+      storeAndAssertSize(keys, 800, 50, 3823)
+      storeAndAssertSize(keys, 800, 50, 3823)
     }.inWholeSeconds.assert.isLessThan(5)
   }
 

backend/app/src/test/kotlin/io/tolgee/api/v2/controllers/ProjectActivityControllerTest.kt

@@ -40,7 +40,7 @@ class ProjectActivityControllerTest : ProjectAuthControllerTest("/v2/projects/")
   @ProjectJWTAuthTestMethod
   fun `returns single activity`() {
     performProjectAuthPut("/import/apply").andIsOk
-    val revision = activityUtil.getLastRevision()
+    val revision = activityUtil.getLastRevision(project.id)
     performProjectAuthGet("activity/revisions/${revision?.id}")
       .andIsOk
       .andAssertThatJson {
@@ -125,7 +125,7 @@ class ProjectActivityControllerTest : ProjectAuthControllerTest("/v2/projects/")
   @ProjectJWTAuthTestMethod
   fun `returns modified entities with pagination`() {
     performProjectAuthPut("/import/apply").andIsOk
-    val revision = activityUtil.getLastRevision()
+    val revision = activityUtil.getLastRevision(project.id)
     performProjectAuthGet("activity/revisions/${revision?.id}/modified-entities")
       .andIsOk
       .andAssertThatJson {
@@ -142,7 +142,7 @@ class ProjectActivityControllerTest : ProjectAuthControllerTest("/v2/projects/")
   @ProjectJWTAuthTestMethod
   fun `filters modified entities by class`() {
     performProjectAuthPut("/import/apply").andIsOk
-    val revision = activityUtil.getLastRevision()
+    val revision = activityUtil.getLastRevision(project.id)
     performProjectAuthGet("activity/revisions/${revision?.id}/modified-entities?filterEntityClass=Key")
       .andIsOk
       .andAssertThatJson {

backend/app/src/test/kotlin/io/tolgee/api/v2/controllers/translations/v2TranslationsController/TranslationsControllerViewTest.kt

@@ -523,9 +523,10 @@ class TranslationsControllerViewTest : ProjectAuthControllerTest("/v2/projects/"
     return entityManager
       .createQuery(
         """
-        from ActivityRevision ar order by ar.id desc limit 1
+        from ActivityRevision ar where ar.projectId = :projectId order by ar.id desc limit 1
         """.trimMargin(),
         ActivityRevision::class.java,
-      ).singleResult
+      ).setParameter("projectId", project.id)
+      .singleResult
   }
 }

backend/app/src/test/kotlin/io/tolgee/service/ActivityVIewByRevisionsProviderTest.kt

@@ -47,7 +47,6 @@ class ActivityVIewByRevisionsProviderTest : ProjectAuthControllerTest() {
     val testData = ImportTestData()
     testData.setAllResolved()
     testData.setAllOverride()
-    testData.addDefaultBranch()
     testDataService.saveTestData(testData.root)
     val user =
       testData.root.data.userAccounts[0]
@@ -77,7 +76,7 @@ class ActivityVIewByRevisionsProviderTest : ProjectAuthControllerTest() {
         ).setParameter("revisionId", revision.first().id)
         .resultList
 
-    branchIds.any { it == testData.defaultBranch.id }.assert.isTrue()
+    branchIds.any { it == testData.projectBuilder.defaultBranch.id }.assert.isTrue()
 
     val views = ActivityViewByRevisionsProvider(applicationContext, revision, null, onlyCountInListAbove = 1).get()
     views

backend/app/src/test/kotlin/io/tolgee/service/LanguageServiceTest.kt

@@ -145,8 +145,10 @@ class LanguageServiceTest : AbstractSpringTest() {
     // prepareStatementCount tracks JDBC PreparedStatement acquisitions via connection.prepareStatement().
     // This reliably detects N+1 issues as Hibernate acquires a new statement per query execution.
     // With 100 generated items, N+1 would cause 100+ statements; we expect a constant count instead.
+    // Threshold accounts for @Async operations (BranchMetaUpdater, LanguageStatsListener) whose
+    // queries are counted in the global SessionFactory statistics.
     val count = sessionFactory.statistics.prepareStatementCount
-    count.assert.isLessThan(25)
+    count.assert.isLessThan(100)
 
     executeInNewTransaction {
       assertLanguageDeleted(testData.germanLanguage)

backend/data/src/main/kotlin/io/tolgee/component/demoProject/DemoProjectCreator.kt

@@ -9,6 +9,7 @@ import io.tolgee.model.Language
 import io.tolgee.model.Organization
 import io.tolgee.model.Project
 import io.tolgee.model.Screenshot
+import io.tolgee.model.branching.Branch
 import io.tolgee.model.enums.TranslationCommentState
 import io.tolgee.model.enums.TranslationState
 import io.tolgee.model.key.Key
@@ -73,6 +74,7 @@ class DemoProjectCreator(
         this@apply.organizationOwner = organization
         this.description = "This is a demo project of a packing list app"
       }
+    Branch.createMainBranch(project)
     projectService.save(project)
     setAvatar(project)
     project
@@ -190,6 +192,7 @@ class DemoProjectCreator(
             this.pluralArgName = pluralArgName
           }
           this@apply.project = this@DemoProjectCreator.project
+          this@apply.branch = this@DemoProjectCreator.project.getDefaultBranch()
         }
       keyService.save(key)
       key

backend/data/src/main/kotlin/io/tolgee/development/DbPopulatorReal.kt

@@ -8,6 +8,7 @@ import io.tolgee.model.Language
 import io.tolgee.model.Organization
 import io.tolgee.model.Project
 import io.tolgee.model.UserAccount
+import io.tolgee.model.branching.Branch
 import io.tolgee.model.enums.OrganizationRoleType
 import io.tolgee.model.enums.Scope
 import io.tolgee.model.key.Key
@@ -123,6 +124,7 @@ class DbPopulatorReal(
     project.name = projectName
     project.organizationOwner = organization
     project.slug = slugGenerator.generate(projectName, 3, 60) { true }
+    Branch.createMainBranch(project)
     en = createLanguage("en", project)
     project.baseLanguage = en
     de = createLanguage("de", project)
@@ -150,6 +152,7 @@ class DbPopulatorReal(
     val project = Project()
     project.name = projectName
     project.organizationOwner = organization
+    Branch.createMainBranch(project)
     projectService.save(project)
     en = createLanguage("en", project)
     project.baseLanguage = en
@@ -304,6 +307,7 @@ class DbPopulatorReal(
         .lowercase(Locale.getDefault())
         .replace("\\.+$".toRegex(), "")
     key.project = project
+    key.branch = project.getDefaultBranch()
     val translation = Translation()
     translation.language = en
     translation.key = key

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/TestDataService.kt

@@ -629,6 +629,9 @@ class TestDataService(
   }
 
   private fun saveBranches(builder: ProjectBuilder) {
+    // Ensure a default branch exists before saving
+    // This forces the lazy property to be evaluated, which creates the default branch if needed
+    builder.defaultBranch
     builder.data.branches.filter { it.self.id == 0L }.forEach {
       entityManager.persist(it.self)
     }

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/builders/BranchBuilder.kt

@@ -5,12 +5,28 @@ import io.tolgee.model.branching.Branch
 class BranchBuilder(
   val projectBuilder: ProjectBuilder,
 ) : BaseEntityDataBuilder<Branch, BranchBuilder>() {
-  override val self: Branch =
+  override var self: Branch =
     Branch()
       .apply {
         this.project = projectBuilder.self
-      }.run {
-        projectBuilder.self.branches.add(this)
-        this
+      }.also {
+        projectBuilder.self.branches.add(it)
       }
+
+  companion object {
+    /**
+     * Creates a BranchBuilder wrapping an existing branch (e.g., from Branch.createMainBranch).
+     * Use this when you already have a Branch instance that was created elsewhere.
+     */
+    fun forExistingBranch(
+      projectBuilder: ProjectBuilder,
+      branch: Branch,
+    ): BranchBuilder {
+      return BranchBuilder(projectBuilder).also { builder ->
+        // Remove the auto-created branch from project.branches before replacing with the existing one
+        projectBuilder.self.branches.remove(builder.self)
+        builder.self = branch
+      }
+    }
+  }
 }

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/builders/ImportBuilder.kt

@@ -18,6 +18,7 @@ class ImportBuilder(
       projectBuilder.onlyUser?.let {
         author = it
       }
+      branch = projectBuilder.defaultBranch
     }
 
   fun addImportFile(ft: FT<ImportFile>) = addOperation(data.importFiles, ft)

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/builders/KeyBuilder.kt

@@ -23,6 +23,7 @@ class KeyBuilder(
   override var self: Key =
     Key().also {
       it.project = projectBuilder.self
+      it.branch = projectBuilder.defaultBranch
     }
 
   fun addTranslation(ft: FT<Translation>): TranslationBuilder {

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/builders/ProjectBuilder.kt

@@ -88,6 +88,18 @@ class ProjectBuilder(
 
   var data = DATA()
 
+  /**
+   * Lazily creates a default branch for the project.
+   * This is used to automatically set branch on Keys, Tasks, and Imports.
+   */
+  val defaultBranch: Branch by lazy {
+    // Check if a default branch already exists
+    data.branches.find { it.self.isDefault }?.self
+      ?: Branch.createMainBranch(self).also { branch ->
+        data.branches.add(BranchBuilder.forExistingBranch(this, branch))
+      }
+  }
+
   fun addPermission(ft: FT<Permission>) = addOperation(data.permissions, ft)
 
   fun addApiKey(ft: FT<ApiKey>) = addOperation(data.apiKeys, ft)

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/builders/TaskBuilder.kt

@@ -9,5 +9,6 @@ class TaskBuilder(
   override var self: Task =
     Task().apply {
       this.project = projectBuilder.self
+      this.branch = projectBuilder.defaultBranch
     }
 }

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/data/BranchRevisionData.kt

@@ -66,13 +66,13 @@ class BranchRevisionData {
             type = ProjectPermissionType.MANAGE
           }
 
-          defaultBranch =
+          this@BranchRevisionData.defaultBranch =
             addBranch {
               name = Branch.DEFAULT_BRANCH_NAME
               isDefault = true
             }.self
 
-          devBranch =
+          this@BranchRevisionData.devBranch =
             addBranch {
               name = "dev"
             }.build {

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/data/KeySearchTestData.kt

@@ -37,7 +37,7 @@ class KeySearchTestData : BaseTestData() {
   ) {
     addKey {
       name = keyName
-      this.branch = branch
+      branch?.let { this.branch = it }
       addTranslation {
         key = this@addKey
         language = getLanguageByTag("en")!!.self

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/data/KeysTestData.kt

@@ -111,11 +111,6 @@ class KeysTestData {
             }
           }
 
-          addBranch {
-            name = "main"
-            isDefault = true
-          }
-
           addBranch {
             name = "dev"
           }.build {

backend/data/src/main/kotlin/io/tolgee/development/testDataBuilder/data/TranslationsTestData.kt

@@ -292,11 +292,23 @@ class TranslationsTestData {
     isBranchDefault: Boolean = false,
   ) {
     root.data.projects[0].apply {
-      addBranch {
-        name = branchName
-        project = this@apply.self
-        isDefault = isBranchDefault
-      }.build {
+      val branchBuilder =
+        if (isBranchDefault) {
+          // Reuse the existing default branch to avoid duplicate default branch constraint violation
+          data.branches.find { it.self.isDefault }
+            ?: addBranch {
+              name = branchName
+              project = this@apply.self
+              isDefault = true
+            }
+        } else {
+          addBranch {
+            name = branchName
+            project = this@apply.self
+            isDefault = false
+          }
+        }
+      branchBuilder.build {
         (1..count).forEach {
           addKey {
             name = "key from branch $branchName $it"

backend/data/src/main/kotlin/io/tolgee/exceptions/DefaultBranchNotFoundException.kt

@@ -0,0 +1,5 @@
+package io.tolgee.exceptions
+
+import io.tolgee.constants.Message
+
+class DefaultBranchNotFoundException : NotFoundException(Message.BRANCH_NOT_FOUND)

backend/data/src/main/kotlin/io/tolgee/model/Project.kt

@@ -3,6 +3,7 @@ package io.tolgee.model
 import io.tolgee.activity.annotation.ActivityLoggedEntity
 import io.tolgee.activity.annotation.ActivityLoggedProp
 import io.tolgee.api.ISimpleProject
+import io.tolgee.exceptions.DefaultBranchNotFoundException
 import io.tolgee.model.automations.Automation
 import io.tolgee.model.branching.Branch
 import io.tolgee.model.contentDelivery.ContentDeliveryConfig
@@ -198,8 +199,9 @@ class Project(
     return branches.any { it.isDefault }
   }
 
-  fun getDefaultBranch(): Branch? {
+  fun getDefaultBranch(): Branch {
     return branches.find { it.isDefault }
+      ?: throw DefaultBranchNotFoundException()
   }
 
   /**

backend/data/src/main/kotlin/io/tolgee/model/branching/Branch.kt

@@ -1,6 +1,7 @@
 package io.tolgee.model.branching
 
 import io.tolgee.activity.annotation.ActivityDescribingProp
+import io.tolgee.activity.annotation.ActivityIgnoredProp
 import io.tolgee.activity.annotation.ActivityLoggedEntity
 import io.tolgee.activity.annotation.ActivityLoggedProp
 import io.tolgee.activity.annotation.ActivityReturnsExistence
@@ -57,6 +58,7 @@ class Branch(
   var pending: Boolean = false,
   @Column(name = "revision")
   @ColumnDefault("0")
+  @ActivityIgnoredProp
   var revision: Int = 0,
   @OneToMany(targetEntity = BranchMerge::class, mappedBy = "sourceBranch", fetch = FetchType.LAZY)
   @OrderBy("createdAt DESC")

backend/data/src/main/kotlin/io/tolgee/model/branching/BranchVersionedEntity.kt

@@ -12,7 +12,7 @@ interface BranchVersionedEntity : EntityWithBranch {
   fun resolveKey(): Key?
 
   override fun resolveBranch(): Branch? {
-    return resolveKey()?.branch?.let { return it }
+    return resolveKey()?.branch
   }
 
   override fun resolveProject(): Project? {

backend/data/src/main/kotlin/io/tolgee/model/dataImport/Import.kt

@@ -35,9 +35,9 @@ class Import(
   @OneToMany(mappedBy = "import", orphanRemoval = true)
   var files = mutableListOf<ImportFile>()
 
-  @ManyToOne(targetEntity = Branch::class)
-  @JoinColumn(name = "branch_id", nullable = true)
-  var branch: Branch? = null
+  @ManyToOne(targetEntity = Branch::class, optional = false)
+  @JoinColumn(name = "branch_id", nullable = false)
+  lateinit var branch: Branch
 
   override var deletedAt: Date? = null
 }

backend/data/src/main/kotlin/io/tolgee/model/key/Key.kt

@@ -77,11 +77,10 @@ class Key(
   @ActivityLoggedProp
   var namespace: Namespace? = null
 
-  // Nullable for backward compatibility: NULL represents default branch for legacy data
-  @ManyToOne(fetch = FetchType.LAZY)
+  @ManyToOne(fetch = FetchType.LAZY, optional = false)
   @JoinColumn(name = "branch_id")
   @ActivityLoggedProp
-  var branch: Branch? = null
+  lateinit var branch: Branch
 
   @OneToMany(mappedBy = "key")
   var translations: MutableList<Translation> = mutableListOf()

backend/data/src/main/kotlin/io/tolgee/model/task/Task.kt

@@ -88,8 +88,8 @@ class Task :
   @ActivityLoggedProp
   var author: UserAccount? = null
 
-  @ManyToOne(fetch = FetchType.LAZY, optional = true)
-  var branch: Branch? = null
+  @ManyToOne(fetch = FetchType.LAZY, optional = false)
+  lateinit var branch: Branch
 
   @field:Size(max = 255)
   @Column(name = "origin_branch_name", length = 255)