@tus/s3-store: finalize incomplete parts

packages/s3-store/index.ts

@@ -504,7 +504,13 @@ export class S3Store extends DataStore {
 
     if (metadata.file.size === newOffset) {
       try {
+        // If no parts exist yet, then the incomplete part needs to be completed
+        const incompletePart = await this.getIncompletePart(id)
+        if (incompletePart) {
+          await this.uploadPart(metadata, incompletePart, nextPartNumber)
+        }
         const parts = await this.retrieveParts(id)
+
         await this.finishMultipartUpload(metadata, parts as Array<AWS.Part>)
         this.clearCache(id)
       } catch (error) {

packages/s3-store/test.ts

@@ -113,6 +113,41 @@ describe('S3DataStore', function () {
     }
   })
 
+  it('completes an incomplete part when deferred length becomes resolved', async function () {
+    const store = this.datastore
+    const incompleteSize = 2 * 1024 * 1024 // 2MB
+    const uploadIncompletePart = sinon.spy(store, 'uploadIncompletePart')
+    const uploadPart = sinon.spy(store, 'uploadPart')
+    const finishMultipartUpload = sinon.spy(store, 'finishMultipartUpload')
+    const upload = new Upload({
+      id: 'deferred-incomplete-part-test-' + Uid.rand(),
+      // Deferred length
+      size: undefined,
+      offset: 0,
+    })
+    let offset = upload.offset
+    await store.create(upload)
+
+    // Upload a single chunk small enough to create an incomplete part
+    offset = await store.write(
+      Readable.from(Buffer.alloc(incompleteSize)),
+      upload.id,
+      offset
+    )
+    assert.equal(uploadIncompletePart.called, true)
+    assert.equal(uploadPart.called, false)
+
+    // Simulate the completion PATCH of a deferred length multipart upload
+    // Resolve the deferred length
+    await store.declareUploadLength(upload.id, incompleteSize)
+    // Notify the store to complete the multipart upload (empty payload)
+    await store.write(Readable.from(Buffer.alloc(0)), upload.id, offset)
+    // The incomplete part will now be completed
+    assert.equal(uploadPart.called, true)
+    // The multipart upload will now be completed
+    assert.equal(finishMultipartUpload.called, true)
+  })
+
   it('upload as multipart upload when incomplete part grows beyond minimal part size', async function () {
     const store = this.datastore
     const size = 10 * 1024 * 1024 // 10MiB