For #12: Add option to stream a download

Author: dhruvit-r

docs/SubmissionsApi.md

@@ -669,6 +669,19 @@ await submissionApiM2MClient.downloadSubmission(submissionId)
 await submissionApiUserCredentialsClient.downloadSubmission(submissionId)
 
 await submissionApiJwtMethodArgClient.downloadSubmission(submissionId, config.JWT)
+
+// Stream Model
+const outputStream = fs.createWriteStream(filePath)
+const req = await submissionApiM2MClient.downloadSubmission(submissionId, artifactId, null, true)
+req.pipe(outputStream)
+
+const outputStream = fs.createWriteStream(filePath)
+const req = await submissionApiUserCredentialsClient.downloadSubmission(submissionId, artifactId, null, true)
+req.pipe(outputStream)
+
+const outputStream = fs.createWriteStream(filePath)
+const req = await submissionApiJwtMethodArgClient.downloadSubmission(submissionId, artifactId, config.JWT, true)
+req.pipe(outputStream)
 ```
 
 ### Demo
@@ -960,6 +973,19 @@ await submissionApiM2MClient.downloadArtifact(submissionId, artifactId)
 await submissionApiUserCredentialsClient.downloadArtifact(submissionId, artifactId)
 
 await submissionApiJwtMethodArgClient.downloadArtifact(submissionId, artifactId, config.JWT)
+
+// Stream Model
+const outputStream = fs.createWriteStream(filePath)
+const req = await submissionApiM2MClient.downloadArtifact(submissionId, artifactId, null, true)
+req.pipe(outputStream)
+
+const outputStream = fs.createWriteStream(filePath)
+const req = await submissionApiUserCredentialsClient.downloadArtifact(submissionId, artifactId, null, true)
+req.pipe(outputStream)
+
+const outputStream = fs.createWriteStream(filePath)
+const req = await submissionApiJwtMethodArgClient.downloadArtifact(submissionId, artifactId, config.JWT, true)
+req.pipe(outputStream)
 ```
 
 ### Demo

index.js

@@ -226,8 +226,8 @@ module.exports = (allConfig) => {
       return require('./src/SubmissionsApi').deleteSubmission(config, submissionId, jwt)
     },
     // Download submission
-    downloadSubmission: (submissionId, jwt) => {
-      return require('./src/SubmissionsApi').downloadSubmission(config, submissionId, jwt)
+    downloadSubmission: (submissionId, jwt, streamed = false) => {
+      return require('./src/SubmissionsApi').downloadSubmission(config, submissionId, jwt, streamed)
     },
     // Create artifact for submission
     createArtifact: (submissionId, reqFormData, jwt) => {
@@ -238,8 +238,8 @@ module.exports = (allConfig) => {
       return require('./src/SubmissionsApi').listArtifacts(config, submissionId, jwt)
     },
     // Download artifact
-    downloadArtifact: (submissionId, artifactId, jwt) => {
-      return require('./src/SubmissionsApi').downloadArtifact(config, submissionId, artifactId, jwt)
+    downloadArtifact: (submissionId, artifactId, jwt, streamed = false) => {
+      return require('./src/SubmissionsApi').downloadArtifact(config, submissionId, artifactId, jwt, streamed)
     },
     // Delete artifact
     deleteArtifact: (submissionId, artifactId, jwt) => {

src/SubmissionsApi.js

@@ -116,10 +116,11 @@ const deleteSubmission = (config, submissionId, jwt = null) => {
  * Function to download submission by id.
  * @param {Object} config Configuration object
  * @param {String} submissionId the submission id
+ * @param {Boolean} streamed Whether a stream is to be returned (Default: false)
  * @returns {Promise} the submission file content
  */
-const downloadSubmission = (config, submissionId, jwt = null) => {
-  return helper.reqToV5APIDownload(config, jwt, `${config.SUBMISSION_API_URL}/submissions/${submissionId}/download`)
+const downloadSubmission = (config, submissionId, jwt = null, streamed = false) => {
+  return helper.reqToV5APIDownload(config, jwt, `${config.SUBMISSION_API_URL}/submissions/${submissionId}/download`, streamed)
 }
 
 /**
@@ -149,10 +150,11 @@ const listArtifacts = (config, submissionId, jwt = null) => {
  * @param {Object} config Configuration object
  * @param {String} submissionId the submission id
  * @param {String} artifactId the artifact id
+ * @param {Boolean} streamed Whether a stream is to be returned (Default: false)
  * @returns {Promise} the artifact file content
  */
-const downloadArtifact = (config, submissionId, artifactId, jwt = null) => {
-  return helper.reqToV5APIDownload(config, jwt, `${config.SUBMISSION_API_URL}/submissions/${submissionId}/artifacts/${artifactId}/download`)
+const downloadArtifact = (config, submissionId, artifactId, jwt = null, streamed = false) => {
+  return helper.reqToV5APIDownload(config, jwt, `${config.SUBMISSION_API_URL}/submissions/${submissionId}/artifacts/${artifactId}/download`, streamed)
 }
 
 /**

src/common/helper.js

@@ -164,14 +164,23 @@ const reqToV5APIWithFile = async (config, jwt, path, formData, fileFieldName) =>
  * Function to download file using V5 API
  * @param {Object} config Configuration object
  * @param {String} jwt The JWT
- * @param (String) path Complete path of the API URL
+ * @param {String} path Complete path of the API URL
+ * @param {Boolean} streamed Whether a stream is to be returned (Default: false)
  * @returns {Promise}
  */
-const reqToV5APIDownload = async (config, jwt, path) => {
+const reqToV5APIDownload = async (config, jwt, path, streamed = false) => {
   const token = await getToken(config, jwt)
-  return request
+  let req = request
     .get(path)
     .set('Authorization', `Bearer ${token}`)
+  if (streamed) {
+    req = req.buffer(false)
+    req.then = undefined
+    req.catch = undefined
+    req.finally = undefined
+    return req
+  }
+  return req
     .buffer(true)
     .parse(function (res, callback) {
       res.data = ''