fix: Default structure delimiter in translations endpoint (#1468)

backend/app/src/main/kotlin/io/tolgee/api/v2/controllers/translation/V2TranslationsController.kt

@@ -65,6 +65,7 @@ import org.springframework.web.bind.annotation.PostMapping
 import org.springframework.web.bind.annotation.PutMapping
 import org.springframework.web.bind.annotation.RequestBody
 import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RequestParam
 import org.springframework.web.bind.annotation.RestController
 import org.springframework.web.context.request.WebRequest
 import java.util.*
@@ -130,7 +131,8 @@ e.g. For key "home.header.title" would result in {"home": {"header": {"title": "
 When null, resulting file will be a flat key-value object.
     """,
     )
-    structureDelimiter: Char? = '.',
+    @RequestParam(value = "structureDelimiter", defaultValue = ".", required = false)
+    structureDelimiter: Char?,
     request: WebRequest
   ): ResponseEntity<Map<String, Any>>? {
     val lastModified: Long = projectTranslationLastModifiedManager.getLastModified(projectHolder.project.id)
@@ -142,7 +144,7 @@ When null, resulting file will be a flat key-value object.
     val response = translationService.getTranslations(
       languageTags = languages,
       projectId = projectHolder.project.id,
-      structureDelimiter = structureDelimiter
+      structureDelimiter = request.getStructureDelimiter()
     )
 
     return ResponseEntity.ok()
@@ -153,6 +155,17 @@ When null, resulting file will be a flat key-value object.
       )
   }
 
+  /**
+   * It has to be handled manually since spring returns default value even when empty value provided
+   */
+  private fun WebRequest.getStructureDelimiter(): Char? {
+    val structureDelimiterParam = this.parameterMap["structureDelimiter"]?.first() ?: return '.'
+    if (structureDelimiterParam == "") {
+      return null
+    }
+    return structureDelimiterParam.toCharArray().first()
+  }
+
   @PutMapping("")
   @AccessWithApiKey(scopes = [ApiScope.TRANSLATIONS_EDIT])
   @AccessWithProjectPermission(permission = Permission.ProjectPermissionType.TRANSLATE)

backend/app/src/test/kotlin/io/tolgee/api/v2/controllers/translations/v2TranslationsController/V2TranslationsControllerViewTest.kt

@@ -326,6 +326,9 @@ class V2TranslationsControllerViewTest : ProjectAuthControllerTest("/v2/projects
     performProjectAuthGet("/translations/en,de?structureDelimiter=+").andIsOk.andAssertThatJson {
       node("en.hello.i.am.plus.scoped").isEqualTo("yupee!")
     }
+    performProjectAuthGet("/translations/en,de").andIsOk.andAssertThatJson {
+      node("en.hello.i.am.scoped").isEqualTo("yupee!")
+    }
   }
 
   @ProjectApiKeyAuthTestMethod(scopes = [ApiScope.TRANSLATIONS_VIEW])