@uppy/companion: fix double tus uploads (#4816)

* fix double uploads

fixes #4815
also improve error logging when canceling

* don't close socket when pausing

because it prevented us from canceling an upload that is paused
note that we here sacrifice the ability to pause uploads and have other uploads take over the paused upload's rate limit queue spot.
this is sacrificed because we will soon remove the ability to pause/resume uploads anyways

* Update packages/@uppy/companion/src/server/Uploader.js

Co-authored-by: Merlijn Vos <merlijn@soverin.net>

* Revert "don't close socket when pausing"

This reverts commit e4dbe77.

---------

Co-authored-by: Merlijn Vos <merlijn@soverin.net>

packages/@uppy/companion/src/server/Uploader.js

@@ -56,10 +56,6 @@ function sanitizeMetadata(inputMetadata) {
   return outputMetadata
 }
 
-class AbortError extends Error {
-  isAbortError = true
-}
-
 class ValidationError extends Error {
   constructor(message) {
     super(message)
@@ -139,6 +135,13 @@ function validateOptions(options) {
   }
 }
 
+const states = {
+  idle: 'idle',
+  uploading: 'uploading',
+  paused: 'paused',
+  done: 'done',
+}
+
 class Uploader {
   /**
    * Uploads file to destination based on the supplied protocol (tus, s3-multipart, multipart)
@@ -176,10 +179,7 @@ class Uploader {
       ? this.options.metadata.name.substring(0, MAX_FILENAME_LENGTH)
       : this.fileName
 
-    this.uploadStopped = false
-
     this.storage = options.storage
-    this._paused = false
 
     this.downloadedBytes = 0
 
@@ -188,15 +188,17 @@ class Uploader {
     if (this.options.protocol === PROTOCOLS.tus) {
       emitter().on(`pause:${this.token}`, () => {
         logger.debug('Received from client: pause', 'uploader', this.shortToken)
-        this._paused = true
+        if (this.#uploadState !== states.uploading) return
+        this.#uploadState = states.paused
         if (this.tus) {
           this.tus.abort()
         }
       })
 
       emitter().on(`resume:${this.token}`, () => {
         logger.debug('Received from client: resume', 'uploader', this.shortToken)
-        this._paused = false
+        if (this.#uploadState !== states.paused) return
+        this.#uploadState = states.uploading
         if (this.tus) {
           this.tus.start()
         }
@@ -205,17 +207,21 @@ class Uploader {
 
     emitter().on(`cancel:${this.token}`, () => {
       logger.debug('Received from client: cancel', 'uploader', this.shortToken)
-      this._paused = true
       if (this.tus) {
         const shouldTerminate = !!this.tus.url
         this.tus.abort(shouldTerminate).catch(() => { })
       }
-      this.abortReadStream(new AbortError())
+      this.#canceled = true
+      this.abortReadStream(new Error('Canceled'))
     })
   }
 
+  #uploadState = states.idle
+
+  #canceled = false
+
   abortReadStream(err) {
-    this.uploadStopped = true
+    this.#uploadState = states.done
     if (this.readStream) this.readStream.destroy(err)
   }
 
@@ -244,7 +250,9 @@ class Uploader {
 
     const onData = (chunk) => {
       this.downloadedBytes += chunk.length
-      if (exceedsMaxFileSize(this.options.companionOptions.maxFileSize, this.downloadedBytes)) this.abortReadStream(new Error('maxFileSize exceeded'))
+      if (exceedsMaxFileSize(this.options.companionOptions.maxFileSize, this.downloadedBytes)) {
+        this.abortReadStream(new Error('maxFileSize exceeded'))
+      }
       this.onProgress(0, undefined)
     }
 
@@ -271,9 +279,11 @@ class Uploader {
    */
   async uploadStream(stream) {
     try {
-      if (this.uploadStopped) throw new Error('Cannot upload stream after upload stopped')
+      if (this.#uploadState !== states.idle) throw new Error('Can only start an upload in the idle state')
       if (this.readStream) throw new Error('Already uploading')
 
+      this.#uploadState = states.uploading
+
       this.readStream = stream
       if (this._needDownloadFirst()) {
         logger.debug('need to download the whole file first', 'controller.get.provider.size', this.shortToken)
@@ -282,7 +292,7 @@ class Uploader {
         // The stream will then typically come from a "Transfer-Encoding: chunked" response
         await this._downloadStreamAsFile(this.readStream)
       }
-      if (this.uploadStopped) return undefined
+      if (this.#uploadState !== states.uploading) return undefined
 
       const { url, extraData } = await Promise.race([
         this._uploadByProtocol(),
@@ -291,6 +301,7 @@ class Uploader {
       ])
       return { url, extraData }
     } finally {
+      this.#uploadState = states.done
       logger.debug('cleanup', this.shortToken)
       if (this.readStream && !this.readStream.destroyed) this.readStream.destroy()
       await this.tryDeleteTmpPath()
@@ -314,11 +325,10 @@ class Uploader {
       const { url, extraData } = ret
       this.#emitSuccess(url, extraData)
     } catch (err) {
-      if (err?.isAbortError) {
+      if (this.#canceled) {
         logger.error('Aborted upload', 'uploader.aborted', this.shortToken)
         return
       }
-      // console.log(err)
       logger.error(err, 'uploader.error', this.shortToken)
       this.#emitError(err)
     } finally {
@@ -458,7 +468,7 @@ class Uploader {
 
     const formattedPercentage = percentage.toFixed(2)
 
-    if (this._paused || this.uploadStopped) {
+    if (this.#uploadState !== states.uploading) {
       return
     }
 
@@ -519,7 +529,8 @@ class Uploader {
     const chunkSize = this.options.chunkSize || (isFileStream ? Infinity : 50e6)
 
     return new Promise((resolve, reject) => {
-      this.tus = new tus.Upload(stream, {
+
+      const tusOptions = {
         endpoint: this.options.endpoint,
         uploadUrl: this.options.uploadUrl,
         uploadLengthDeferred: !isFileStream,
@@ -564,11 +575,11 @@ class Uploader {
         onSuccess() {
           resolve({ url: uploader.tus.url })
         },
-      })
-
-      if (!this._paused) {
-        this.tus.start()
       }
+
+      this.tus = new tus.Upload(stream, tusOptions)
+
+      this.tus.start()
     })
   }