KTOR-6632 Support receiving multipart data with Ktor client

buildSrc/src/main/kotlin/test/server/tests/MultiPartFormData.kt

@@ -4,6 +4,7 @@
 
 package test.server.tests
 
+import io.ktor.client.request.forms.*
 import io.ktor.http.*
 import io.ktor.http.content.*
 import io.ktor.server.application.*
@@ -34,6 +35,18 @@ internal fun Application.multiPartFormDataTest() {
                 call.receiveMultipart().readPart()
                 call.respond(HttpStatusCode.OK)
             }
+            post("receive") {
+                val multipart = MultiPartFormDataContent(
+                    formData {
+                        append("text", "Hello, World!")
+                        append("file", ByteArray(1024) { it.toByte() }, Headers.build {
+                            append(HttpHeaders.ContentDisposition, """form-data; name="file"; filename="test.bin"""")
+                            append(HttpHeaders.ContentType, ContentType.Application.OctetStream.toString())
+                        })
+                    }
+                )
+                call.respond(multipart)
+            }
         }
     }
 }

ktor-client/ktor-client-core/build.gradle.kts

@@ -8,6 +8,7 @@ kotlin.sourceSets {
     commonMain {
         dependencies {
             api(project(":ktor-http"))
+            api(project(":ktor-http:ktor-http-cio"))
             api(project(":ktor-shared:ktor-events"))
             api(project(":ktor-shared:ktor-websocket-serialization"))
             api(project(":ktor-shared:ktor-sse"))

ktor-client/ktor-client-core/common/src/io/ktor/client/plugins/DefaultTransform.kt

@@ -8,6 +8,7 @@ import io.ktor.client.*
 import io.ktor.client.request.*
 import io.ktor.client.statement.*
 import io.ktor.http.*
+import io.ktor.http.cio.*
 import io.ktor.http.content.*
 import io.ktor.util.logging.*
 import io.ktor.utils.io.*
@@ -111,6 +112,22 @@ public fun HttpClient.defaultTransformers() {
                 proceedWith(HttpResponseContainer(info, response.status))
             }
 
+            MultiPartData::class -> {
+                val rawContentType = checkNotNull(context.response.headers[HttpHeaders.ContentType]) {
+                    "No content type provided for multipart"
+                }
+                val contentType = ContentType.parse(rawContentType)
+                check(contentType.match(ContentType.MultiPart.FormData)) {
+                    "Expected multipart/form-data, got $contentType"
+                }
+
+                val contentLength = context.response.headers[HttpHeaders.ContentLength]?.toLong()
+                val body = CIOMultipartDataBase(coroutineContext, body, rawContentType, contentLength)
+                val parsedResponse = HttpResponseContainer(info, body)
+
+                proceedWith(parsedResponse)
+            }
+
             else -> null
         }
         if (result != null) {

ktor-client/ktor-client-tests/common/test/io/ktor/client/tests/MultiPartFormDataTest.kt

@@ -4,13 +4,15 @@
 
 package io.ktor.client.tests
 
+import io.ktor.client.call.*
 import io.ktor.client.request.*
 import io.ktor.client.request.forms.*
 import io.ktor.client.tests.utils.*
 import io.ktor.http.*
+import io.ktor.http.content.*
+import io.ktor.utils.io.*
 import kotlinx.io.*
 import kotlin.test.*
-import kotlin.time.*
 
 /**
  * Tests client request with multi-part form data.
@@ -48,4 +50,41 @@ class MultiPartFormDataTest : ClientLoader() {
             assertTrue(response.status.isSuccess())
         }
     }
+
+    @Test
+    fun testReceiveMultiPartFormData() = clientTests {
+        test { client ->
+            val response = client.post("$TEST_SERVER/multipart/receive")
+
+            val multipart = response.body<MultiPartData>()
+            var textFound = false
+            var fileFound = false
+
+            multipart.forEachPart { part ->
+                when (part) {
+                    is PartData.FormItem -> {
+                        assertEquals("text", part.name)
+                        assertEquals("Hello, World!", part.value)
+                        textFound = true
+                    }
+                    is PartData.FileItem -> {
+                        assertEquals("file", part.name)
+                        assertEquals("test.bin", part.originalFileName)
+
+                        val bytes = part.provider().readRemaining().readByteArray()
+                        assertEquals(1024, bytes.size)
+                        for (i in bytes.indices) {
+                            assertEquals(i.toByte(), bytes[i])
+                        }
+                        fileFound = true
+                    }
+                    else -> fail("Unexpected part type: ${part::class.simpleName}")
+                }
+                part.dispose()
+            }
+
+            assertTrue(textFound, "Text part not found")
+            assertTrue(fileFound, "File part not found")
+        }
+    }
 }

ktor-http/ktor-http-cio/api/ktor-http-cio.klib.api

@@ -40,6 +40,15 @@ final class io.ktor.http.cio/CIOHeaders : io.ktor.http/Headers { // io.ktor.http
     final fun names(): kotlin.collections/Set<kotlin/String> // io.ktor.http.cio/CIOHeaders.names|names(){}[0]
 }
 
+final class io.ktor.http.cio/CIOMultipartDataBase : io.ktor.http.content/MultiPartData, kotlinx.coroutines/CoroutineScope { // io.ktor.http.cio/CIOMultipartDataBase|null[0]
+    constructor <init>(kotlin.coroutines/CoroutineContext, io.ktor.utils.io/ByteReadChannel, kotlin/CharSequence, kotlin/Long?, kotlin/Long = ...) // io.ktor.http.cio/CIOMultipartDataBase.<init>|<init>(kotlin.coroutines.CoroutineContext;io.ktor.utils.io.ByteReadChannel;kotlin.CharSequence;kotlin.Long?;kotlin.Long){}[0]
+
+    final val coroutineContext // io.ktor.http.cio/CIOMultipartDataBase.coroutineContext|{}coroutineContext[0]
+        final fun <get-coroutineContext>(): kotlin.coroutines/CoroutineContext // io.ktor.http.cio/CIOMultipartDataBase.coroutineContext.<get-coroutineContext>|<get-coroutineContext>(){}[0]
+
+    final suspend fun readPart(): io.ktor.http.content/PartData? // io.ktor.http.cio/CIOMultipartDataBase.readPart|readPart(){}[0]
+}
+
 final class io.ktor.http.cio/ConnectionOptions { // io.ktor.http.cio/ConnectionOptions|null[0]
     constructor <init>(kotlin/Boolean = ..., kotlin/Boolean = ..., kotlin/Boolean = ..., kotlin.collections/List<kotlin/String> = ...) // io.ktor.http.cio/ConnectionOptions.<init>|<init>(kotlin.Boolean;kotlin.Boolean;kotlin.Boolean;kotlin.collections.List<kotlin.String>){}[0]
 
@@ -117,9 +126,44 @@ final class io.ktor.http.cio/Response : io.ktor.http.cio/HttpMessage { // io.kto
         final fun <get-version>(): kotlin/CharSequence // io.ktor.http.cio/Response.version.<get-version>|<get-version>(){}[0]
 }
 
+sealed class io.ktor.http.cio/MultipartEvent { // io.ktor.http.cio/MultipartEvent|null[0]
+    abstract fun release() // io.ktor.http.cio/MultipartEvent.release|release(){}[0]
+
+    final class Epilogue : io.ktor.http.cio/MultipartEvent { // io.ktor.http.cio/MultipartEvent.Epilogue|null[0]
+        constructor <init>(kotlinx.io/Source) // io.ktor.http.cio/MultipartEvent.Epilogue.<init>|<init>(kotlinx.io.Source){}[0]
+
+        final val body // io.ktor.http.cio/MultipartEvent.Epilogue.body|{}body[0]
+            final fun <get-body>(): kotlinx.io/Source // io.ktor.http.cio/MultipartEvent.Epilogue.body.<get-body>|<get-body>(){}[0]
+
+        final fun release() // io.ktor.http.cio/MultipartEvent.Epilogue.release|release(){}[0]
+    }
+
+    final class MultipartPart : io.ktor.http.cio/MultipartEvent { // io.ktor.http.cio/MultipartEvent.MultipartPart|null[0]
+        constructor <init>(kotlinx.coroutines/Deferred<io.ktor.http.cio/HttpHeadersMap>, io.ktor.utils.io/ByteReadChannel) // io.ktor.http.cio/MultipartEvent.MultipartPart.<init>|<init>(kotlinx.coroutines.Deferred<io.ktor.http.cio.HttpHeadersMap>;io.ktor.utils.io.ByteReadChannel){}[0]
+
+        final val body // io.ktor.http.cio/MultipartEvent.MultipartPart.body|{}body[0]
+            final fun <get-body>(): io.ktor.utils.io/ByteReadChannel // io.ktor.http.cio/MultipartEvent.MultipartPart.body.<get-body>|<get-body>(){}[0]
+        final val headers // io.ktor.http.cio/MultipartEvent.MultipartPart.headers|{}headers[0]
+            final fun <get-headers>(): kotlinx.coroutines/Deferred<io.ktor.http.cio/HttpHeadersMap> // io.ktor.http.cio/MultipartEvent.MultipartPart.headers.<get-headers>|<get-headers>(){}[0]
+
+        final fun release() // io.ktor.http.cio/MultipartEvent.MultipartPart.release|release(){}[0]
+    }
+
+    final class Preamble : io.ktor.http.cio/MultipartEvent { // io.ktor.http.cio/MultipartEvent.Preamble|null[0]
+        constructor <init>(kotlinx.io/Source) // io.ktor.http.cio/MultipartEvent.Preamble.<init>|<init>(kotlinx.io.Source){}[0]
+
+        final val body // io.ktor.http.cio/MultipartEvent.Preamble.body|{}body[0]
+            final fun <get-body>(): kotlinx.io/Source // io.ktor.http.cio/MultipartEvent.Preamble.body.<get-body>|<get-body>(){}[0]
+
+        final fun release() // io.ktor.http.cio/MultipartEvent.Preamble.release|release(){}[0]
+    }
+}
+
 final fun (kotlin/CharSequence).io.ktor.http.cio.internals/parseDecLong(): kotlin/Long // io.ktor.http.cio.internals/parseDecLong|[email protected](){}[0]
 final fun (kotlinx.coroutines/CoroutineScope).io.ktor.http.cio/decodeChunked(io.ktor.utils.io/ByteReadChannel): io.ktor.utils.io/WriterJob // io.ktor.http.cio/decodeChunked|[email protected](io.ktor.utils.io.ByteReadChannel){}[0]
 final fun (kotlinx.coroutines/CoroutineScope).io.ktor.http.cio/decodeChunked(io.ktor.utils.io/ByteReadChannel, kotlin/Long): io.ktor.utils.io/WriterJob // io.ktor.http.cio/decodeChunked|[email protected](io.ktor.utils.io.ByteReadChannel;kotlin.Long){}[0]
+final fun (kotlinx.coroutines/CoroutineScope).io.ktor.http.cio/parseMultipart(io.ktor.utils.io/ByteReadChannel, io.ktor.http.cio/HttpHeadersMap, kotlin/Long = ...): kotlinx.coroutines.channels/ReceiveChannel<io.ktor.http.cio/MultipartEvent> // io.ktor.http.cio/parseMultipart|[email protected](io.ktor.utils.io.ByteReadChannel;io.ktor.http.cio.HttpHeadersMap;kotlin.Long){}[0]
+final fun (kotlinx.coroutines/CoroutineScope).io.ktor.http.cio/parseMultipart(io.ktor.utils.io/ByteReadChannel, kotlin/CharSequence, kotlin/Long?, kotlin/Long = ...): kotlinx.coroutines.channels/ReceiveChannel<io.ktor.http.cio/MultipartEvent> // io.ktor.http.cio/parseMultipart|[email protected](io.ktor.utils.io.ByteReadChannel;kotlin.CharSequence;kotlin.Long?;kotlin.Long){}[0]
 final fun io.ktor.http.cio/encodeChunked(io.ktor.utils.io/ByteWriteChannel, kotlin.coroutines/CoroutineContext): io.ktor.utils.io/ReaderJob // io.ktor.http.cio/encodeChunked|encodeChunked(io.ktor.utils.io.ByteWriteChannel;kotlin.coroutines.CoroutineContext){}[0]
 final fun io.ktor.http.cio/expectHttpBody(io.ktor.http.cio/Request): kotlin/Boolean // io.ktor.http.cio/expectHttpBody|expectHttpBody(io.ktor.http.cio.Request){}[0]
 final fun io.ktor.http.cio/expectHttpBody(io.ktor.http/HttpMethod, kotlin/Long, kotlin/CharSequence?, io.ktor.http.cio/ConnectionOptions?, kotlin/CharSequence?): kotlin/Boolean // io.ktor.http.cio/expectHttpBody|expectHttpBody(io.ktor.http.HttpMethod;kotlin.Long;kotlin.CharSequence?;io.ktor.http.cio.ConnectionOptions?;kotlin.CharSequence?){}[0]

ktor-http/ktor-http-cio/jvm/src/io/ktor/http/cio/CIOMultipartDataBase.kt → ktor-http/ktor-http-cio/common/src/io/ktor/http/cio/CIOMultipartDataBase.kt

@@ -49,7 +49,7 @@ public class CIOMultipartDataBase(
                 val event = events.receive()
                 eventToData(event)?.let { return it }
             }
-        } catch (t: ClosedReceiveChannelException) {
+        } catch (_: ClosedReceiveChannelException) {
             return null
         }
     }
@@ -77,13 +77,7 @@ public class CIOMultipartDataBase(
 
         val body = part.body
         if (filename == null) {
-            val packet = body.readRemaining() // formFieldLimit.toLong())
-//            if (!body.exhausted()) {
-//                val cause = IllegalStateException("Form field size limit exceeded: $formFieldLimit")
-//                body.cancel(cause)
-//                throw cause
-//            }
-
+            val packet = body.readRemaining()
             packet.use {
                 return PartData.FormItem(it.readText(), { part.release() }, CIOHeaders(headers))
             }