Fixes form submissions with empty file fields throwing exceptions

com-lihaoyi · Nov 12, 2024 · c722ec2 · c722ec2
1 parent fae83f8
commit c722ec2
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Showing 6 changed files with 96 additions and 5 deletions.
diff --git a/build.mill b/build.mill
@@ -125,6 +125,7 @@ def zippedExamples = T {
     build.example.websockets2.millSourcePath,
     build.example.websockets3.millSourcePath,
     build.example.websockets4.millSourcePath,
+    build.example.multipartFormSubmission.millSourcePath,
   )
 
   for (example <- examples) yield {

diff --git a/cask/src/cask/model/Params.scala b/cask/src/cask/model/Params.scala
@@ -1,10 +1,12 @@
 package cask.model
 
 import java.io.{ByteArrayOutputStream, InputStream}
-
 import cask.internal.Util
 import io.undertow.server.HttpServerExchange
 import io.undertow.server.handlers.CookieImpl
+import io.undertow.util.HttpString
+import scala.util.Try
+import scala.collection.JavaConverters.collectionAsScalaIterableConverter
 
 case class QueryParams(value: Map[String, collection.Seq[String]])
 case class RemainingPathSegments(value: Seq[String])
@@ -98,9 +100,13 @@ sealed trait FormEntry{
   }
 }
 object FormEntry{
-  def fromUndertow(from: io.undertow.server.handlers.form.FormData.FormValue) = {
-    if (!from.isFile) FormValue(from.getValue, from.getHeaders)
-    else FormFile(from.getFileName, from.getPath, from.getHeaders)
+  def fromUndertow(from: io.undertow.server.handlers.form.FormData.FormValue): FormEntry = {
+    val isOctetStream = Option(from.getHeaders)
+      .flatMap(headers => Option(headers.get(HttpString.tryFromString("Content-Type"))))
+      .exists(h => h.asScala.exists(v => v == "application/octet-stream"))
+    // browsers will set empty file fields to content type: octet-stream
+    if (isOctetStream || from.isFileItem) FormFile(from.getFileName, Try(from.getFileItem.getFile).toOption, from.getHeaders)
+    else FormValue(from.getValue, from.getHeaders)
   }
 
 }
@@ -110,7 +116,9 @@ case class FormValue(value: String,
 }
 
 case class FormFile(fileName: String,
-                    filePath: java.nio.file.Path,
+                    filePath: Option[java.nio.file.Path],
                     headers: io.undertow.util.HeaderMap) extends FormEntry{
   def valueOrFileName = fileName
 }
+
+case class EmptyFormEntry()
diff --git a/example/multipartFormSubmission/app/resources/example.txt b/example/multipartFormSubmission/app/resources/example.txt
diff --git a/example/multipartFormSubmission/app/src/MultipartFormSubmission.scala b/example/multipartFormSubmission/app/src/MultipartFormSubmission.scala
@@ -0,0 +1,26 @@
+package app
+
+object MultipartFormSubmission extends cask.MainRoutes {
+
+  @cask.get("/")
+  def index() =
+    cask.model.Response(
+      """
+    <!DOCTYPE html>
+    <html lang="en">
+    <head></head>
+    <body>
+        <form action="/post" method="post" enctype="multipart/form-data">
+            <input type="file" id="somefile" name="somefile">
+            <button type="submit">Submit</button>
+        </form>
+    </body>
+    </html>
+    """, 200, Seq(("Content-Type", "text/html")))
+
+  @cask.postForm("/post")
+  def post(somefile: cask.FormFile) =
+    s"filename: ${somefile.fileName}"
+
+  initialize()
+}
diff --git a/example/multipartFormSubmission/app/test/src/ExampleTests.scala b/example/multipartFormSubmission/app/test/src/ExampleTests.scala
@@ -0,0 +1,38 @@
+package app
+import io.undertow.Undertow
+
+import utest._
+
+object ExampleTests extends TestSuite{
+  def withServer[T](example: cask.main.Main)(f: String => T): T = {
+    val server = Undertow.builder
+      .addHttpListener(8081, "localhost")
+      .setHandler(example.defaultHandler)
+      .build
+    server.start()
+    val res =
+      try f("http://localhost:8081")
+      finally server.stop()
+    res
+  }
+
+  val tests = Tests{
+    test("MultipartFormSubmission") - withServer(MultipartFormSubmission){ host =>
+      val classPath = System.getProperty("java.class.path", ".");
+      val elements = classPath.split(System.getProperty("path.separator"));
+      elements.filter(e => e.endsWith("/app/resources")).headOption.map(resourcePath => {
+        val withFile = requests.post(s"$host/post", data = requests.MultiPart(
+          requests.MultiItem("somefile", new java.io.File(s"$resourcePath/example.txt"), "example.txt"),
+        ))
+        withFile.text() ==> s"filename: example.txt"
+        withFile.statusCode ==> 200
+
+        val withoutFile = requests.post(s"$host/post", data = requests.MultiPart(
+          requests.MultiItem("somefile", Array[Byte]()),
+        ))
+        withoutFile.text() ==> s"filename: null"
+        withoutFile.statusCode ==> 200
+      }).isDefined ==> true
+    }
+  }
+}
diff --git a/example/multipartFormSubmission/package.mill b/example/multipartFormSubmission/package.mill
@@ -0,0 +1,18 @@
+package build.example.multipartFormSubmission
+import mill._, scalalib._
+
+object app extends Cross[AppModule](build.scalaVersions)
+trait AppModule extends CrossScalaModule{
+
+  def moduleDeps = Seq(build.cask(crossScalaVersion))
+
+  def ivyDeps = Agg[Dep](
+  )
+  object test extends ScalaTests with TestModule.Utest{
+
+    def ivyDeps = Agg(
+      ivy"com.lihaoyi::utest::0.8.4",
+      ivy"com.lihaoyi::requests::0.9.0",
+    )
+  }
+}