Force Content-Length HTTP header in import responses.

Previously, the Content-Length was missing and there was:
  Transfer-Encoding: chunked

Author: jarkkoka

src/main/kotlin/fi/hsl/jore4/hastus/api/ImportController.kt

@@ -1,9 +1,11 @@
 package fi.hsl.jore4.hastus.api
 
+import com.fasterxml.jackson.databind.ObjectMapper
 import fi.hsl.jore4.hastus.Constants.MIME_TYPE_CSV
 import fi.hsl.jore4.hastus.service.importing.ImportService
 import mu.KotlinLogging
-import org.springframework.http.HttpStatus
+import org.springframework.http.HttpHeaders
+import org.springframework.http.MediaType
 import org.springframework.http.ResponseEntity
 import org.springframework.web.bind.annotation.ExceptionHandler
 import org.springframework.web.bind.annotation.PostMapping
@@ -12,6 +14,7 @@ import org.springframework.web.bind.annotation.RequestHeader
 import org.springframework.web.bind.annotation.RequestMapping
 import org.springframework.web.bind.annotation.RestController
 import org.springframework.web.server.ResponseStatusException
+import java.io.Serializable
 import java.util.UUID
 import kotlin.time.ExperimentalTime
 import kotlin.time.measureTimedValue
@@ -22,22 +25,23 @@ private val LOGGER = KotlinLogging.logger {}
 @RestController
 @RequestMapping("import")
 class ImportController(
-    private val importService: ImportService
+    private val importService: ImportService,
+    private val objectMapper: ObjectMapper
 ) {
 
     data class ImportTimetablesSuccessResult(
         val vehicleScheduleFrameId: UUID?
-    )
+    ) : Serializable
 
     data class ImportTimetablesFailureResult(
         val reason: String?
-    )
+    ) : Serializable
 
     @PostMapping("", consumes = [MIME_TYPE_CSV])
     fun importCsvFile(
         @RequestBody csv: String,
         @RequestHeader headers: Map<String, String>
-    ): ImportTimetablesSuccessResult {
+    ): ResponseEntity<String> {
         val (nullableVehicleScheduleFrameId, elapsed) = measureTimedValue {
             LOGGER.info("Starting to import timetables from CSV file...")
 
@@ -55,26 +59,36 @@ class ImportController(
 
         LOGGER.info { "CSV import processing completed in $elapsed" }
 
-        return ImportTimetablesSuccessResult(nullableVehicleScheduleFrameId)
+        return ResponseEntity.ok()
+            .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+            .body(
+                serialise(
+                    ImportTimetablesSuccessResult(nullableVehicleScheduleFrameId)
+                )
+            )
     }
 
     @ExceptionHandler
-    fun handleExportException(ex: Exception): ResponseEntity<ImportTimetablesFailureResult> {
+    fun handleExportException(ex: Exception): ResponseEntity<String> {
         return when (ex) {
             is ResponseStatusException -> {
                 ResponseEntity
                     .status(ex.statusCode)
-                    .body(ImportTimetablesFailureResult(ex.reason))
+                    .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+                    .body(serialise(ImportTimetablesFailureResult(ex.reason)))
             }
 
             else -> {
                 LOGGER.error { "Exception during import request:$ex" }
                 LOGGER.error(ex.stackTraceToString())
 
                 ResponseEntity
-                    .status(HttpStatus.INTERNAL_SERVER_ERROR)
-                    .body(ImportTimetablesFailureResult(ex.message))
+                    .internalServerError()
+                    .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+                    .body(serialise(ImportTimetablesFailureResult(ex.message)))
             }
         }
     }
+
+    private fun serialise(obj: Serializable): String = objectMapper.writeValueAsString(obj)
 }

src/test/kotlin/fi/hsl/jore4/hastus/api/ImportControllerTest.kt

@@ -68,7 +68,7 @@ class ImportControllerTest @Autowired constructor(
 
         executeImportTimetablesRequest("<some_csv_content>")
             .andExpect(status().isOk)
-            .andExpect(header().doesNotExist(HttpHeaders.CONTENT_LENGTH))
+            .andExpect(header().exists(HttpHeaders.CONTENT_LENGTH))
             .andExpect(
                 content().json(
                     """
@@ -95,7 +95,7 @@ class ImportControllerTest @Autowired constructor(
 
         executeImportTimetablesRequest("<invalid_csv_content>")
             .andExpect(status().isBadRequest)
-            .andExpect(header().doesNotExist(HttpHeaders.CONTENT_LENGTH))
+            .andExpect(header().exists(HttpHeaders.CONTENT_LENGTH))
             .andExpect(
                 constructExpectedErrorBody(resultErrorMessage)
             )
@@ -118,7 +118,7 @@ class ImportControllerTest @Autowired constructor(
 
         executeImportTimetablesRequest("<csv_content>")
             .andExpect(status().isBadRequest)
-            .andExpect(header().doesNotExist(HttpHeaders.CONTENT_LENGTH))
+            .andExpect(header().exists(HttpHeaders.CONTENT_LENGTH))
             .andExpect(
                 constructExpectedErrorBody(
                     "Could not find journey pattern reference for Hastus trips with the following route " +
@@ -141,7 +141,7 @@ class ImportControllerTest @Autowired constructor(
 
         executeImportTimetablesRequest("<csv_content>")
             .andExpect(status().isBadRequest)
-            .andExpect(header().doesNotExist(HttpHeaders.CONTENT_LENGTH))
+            .andExpect(header().exists(HttpHeaders.CONTENT_LENGTH))
             .andExpect(
                 constructExpectedErrorBody(
                     "No journey pattern reference was found whose stop points correspond to the Hastus trip: " +
@@ -164,7 +164,7 @@ class ImportControllerTest @Autowired constructor(
 
         executeImportTimetablesRequest("<csv_content>")
             .andExpect(status().isForbidden)
-            .andExpect(header().doesNotExist(HttpHeaders.CONTENT_LENGTH))
+            .andExpect(header().exists(HttpHeaders.CONTENT_LENGTH))
             .andExpect(
                 constructExpectedErrorBody(resultErrorMessage)
             )
@@ -184,7 +184,7 @@ class ImportControllerTest @Autowired constructor(
 
         executeImportTimetablesRequest("<csv_content>")
             .andExpect(status().isInternalServerError)
-            .andExpect(header().doesNotExist(HttpHeaders.CONTENT_LENGTH))
+            .andExpect(header().exists(HttpHeaders.CONTENT_LENGTH))
             .andExpect(
                 constructExpectedErrorBody(resultErrorMessage)
             )