fix: file uploader error handling and tests

src/FileUploader.ts

@@ -1,6 +1,7 @@
 import { isLogInRequired, needsRetry, isUrl } from './utils'
 import { CsrfToken } from './types/CsrfToken'
 import { UploadFile } from './types/UploadFile'
+import { ErrorResponse } from './types'
 
 const requestRetryLimit = 5
 
@@ -18,29 +19,29 @@ export class FileUploader {
   private retryCount = 0
 
   public uploadFile(sasJob: string, files: UploadFile[], params: any) {
-    if (files?.length < 1)
-      throw new Error('At least one file must be provided.')
-
-    let paramsString = ''
-
-    for (let param in params) {
-      if (params.hasOwnProperty(param)) {
-        paramsString += `&${param}=${params[param]}`
-      }
-    }
-
-    const program = this.appLoc
-      ? this.appLoc.replace(/\/?$/, '/') + sasJob.replace(/^\//, '')
-      : sasJob
-    const uploadUrl = `${this.serverUrl}${this.jobsPath}/?${
-      '_program=' + program
-    }${paramsString}`
-
-    const headers = {
-      'cache-control': 'no-cache'
-    }
-
     return new Promise((resolve, reject) => {
+      if (files?.length < 1) reject(new ErrorResponse('At least one file must be provided.'))
+      if (!sasJob || sasJob === '') reject(new ErrorResponse('sasJob must be provided.'))
+
+      let paramsString = ''
+
+      for (let param in params) {
+        if (params.hasOwnProperty(param)) {
+          paramsString += `&${param}=${params[param]}`
+        }
+      }
+
+      const program = this.appLoc
+        ? this.appLoc.replace(/\/?$/, '/') + sasJob.replace(/^\//, '')
+        : sasJob
+      const uploadUrl = `${this.serverUrl}${this.jobsPath}/?${
+        '_program=' + program
+      }${paramsString}`
+
+      const headers = {
+        'cache-control': 'no-cache'
+      }
+
       const formData = new FormData()
 
       for (let file of files) {
@@ -48,7 +49,7 @@ export class FileUploader {
       }
 
       if (this.csrfToken) formData.append('_csrf', this.csrfToken.value)
-
+      
       fetch(uploadUrl, {
         method: 'POST',
         body: formData,
@@ -76,7 +77,7 @@ export class FileUploader {
         })
         .then((responseText) => {
           if (isLogInRequired(responseText))
-            reject('You must be logged in to upload a file')
+            reject(new ErrorResponse('You must be logged in to upload a file.'))
 
           if (needsRetry(responseText)) {
             if (this.retryCount < requestRetryLimit) {
@@ -95,12 +96,12 @@ export class FileUploader {
             try {
               resolve(JSON.parse(responseText))
             } catch (e) {
-              reject(e)
+              reject(new ErrorResponse('Error while parsing json from upload response.', e))
             }
           }
         })
         .catch((err: any) => {
-          reject(err)
+          reject(new ErrorResponse('Upload request failed.', err))
         })
     })
   }