Single Attachment Bug Fixes

lib/generic-handlers.js

@@ -73,6 +73,24 @@ async function finalizePrepareAttachment(data, req, prefix) {
   }
   attachmentData.ID ??= cds.utils.uuid()
 
+  // On stream PUT, filename is not in req.data — fetch it from the DB record
+  if (prefix && !attachmentData.filename && req?.target && req?.params) {
+    const dbKeys = Object.fromEntries(
+      Object.entries(req.params?.at(-1) || {}).filter(
+        ([k]) => k !== "IsActiveEntity",
+      ),
+    )
+    if (Object.keys(dbKeys).length > 0) {
+      const draftTarget = req.target.drafts || req.target
+      const record = await SELECT.one
+        .from(draftTarget, dbKeys)
+        .columns(`${prefix}_filename`)
+      if (record?.[`${prefix}_filename`]) {
+        attachmentData.filename = record[`${prefix}_filename`]
+      }
+    }
+  }
+
   let ext = attachmentData.filename
     ? extname(attachmentData.filename).toLowerCase().slice(1)
     : null

lib/plugin.js

@@ -247,7 +247,11 @@ cds.once("served", () => {
  */
 function unfoldModel(csn) {
   const meta = (csn.meta ??= {})
-  if (!("sap.attachments.Attachments" in csn.definitions)) return
+  if (
+    !("sap.attachments.Attachments" in csn.definitions) &&
+    !("sap.attachments.Attachment" in csn.definitions)
+  )
+    return
   if (meta._enhanced_for_attachments) return
   // const csnCopy = structuredClone(csn) // REVISIT: Why did we add this cloning?
   const hasFacetForComp = (name, facets) =>
@@ -598,11 +602,10 @@ cds.ApplicationService.handle_attachments = cds.service.impl(async function () {
 
         if (!prefix) return next()
 
+        await onPrepareAttachment(req)
         if (!validateAttachmentMimeType(req)) return
         if (!(await validateAttachmentSize(req))) return
 
-        await onPrepareAttachment(req)
-
         if (getAttachmentKind() !== "db") {
           await putInlineAttachmentObjectStore(req, prefix)
         } else {

tests/integration/attachments.test.js

@@ -2922,6 +2922,67 @@ describe("Tests for single attachment entity", () => {
     })
     expect(Buffer.concat(chunks).length).toBeGreaterThan(0)
   })
+
+  it("Should accept upload when file type matches @Core.AcceptableMediaTypes on inline attachment", async () => {
+    const svc = await cds.connect.to("ProcessorService")
+    const el = svc.entities.SingleAttachment.elements.myAttachment_content
+    const origTypes = el["@Core.AcceptableMediaTypes"]
+    el["@Core.AcceptableMediaTypes"] = ["application/pdf"]
+
+    try {
+      const { data: singleAttachment } = await POST(
+        "/odata/v4/processor/SingleAttachment",
+        { name: "Mime type allowed test", myAttachment_filename: "sample.pdf" },
+      )
+
+      const filepath = join(__dirname, "content/sample.pdf")
+      const fileContent = readFileSync(filepath)
+
+      const putRes = await PUT(
+        `/odata/v4/processor/SingleAttachment(ID=${singleAttachment.ID},IsActiveEntity=false)/myAttachment_content`,
+        fileContent,
+        { headers: { "Content-Type": "application/pdf" } },
+      )
+      expect(putRes.status).toEqual(204)
+    } finally {
+      el["@Core.AcceptableMediaTypes"] = origTypes
+    }
+  })
+
+  it("Should reject upload when file type does not match @Core.AcceptableMediaTypes on inline attachment", async () => {
+    const svc = await cds.connect.to("ProcessorService")
+    const el = svc.entities.SingleAttachment.elements.myAttachment_content
+    const origTypes = el["@Core.AcceptableMediaTypes"]
+    el["@Core.AcceptableMediaTypes"] = ["image/jpeg"]
+
+    try {
+      const { data: singleAttachment } = await POST(
+        "/odata/v4/processor/SingleAttachment",
+        {
+          name: "Mime type rejected test",
+          myAttachment_filename: "sample.pdf",
+        },
+      )
+
+      const filepath = join(__dirname, "content/sample.pdf")
+      const fileContent = readFileSync(filepath)
+
+      let expectedError
+      await PUT(
+        `/odata/v4/processor/SingleAttachment(ID=${singleAttachment.ID},IsActiveEntity=false)/myAttachment_content`,
+        fileContent,
+        { headers: { "Content-Type": "application/pdf" } },
+      ).catch((e) => {
+        expectedError = e
+      })
+      expect(expectedError?.response?.status).toEqual(400)
+      expect(expectedError?.response?.data?.error?.message).toMatch(
+        "The attachment file type 'application/pdf' is not allowed.",
+      )
+    } finally {
+      el["@Core.AcceptableMediaTypes"] = origTypes
+    }
+  })
 })
 
 describe("Tests for attachments facet disable", () => {