fix: Fix getReadStream delay reading (#790)

src/api-request-manager.ts

@@ -9,6 +9,8 @@
 import { Promise } from 'bluebird';
 import { EventEmitter } from 'events';
 import errors from './util/errors';
+import { PassThrough } from 'stream';
+import request from 'request';
 
 const APIRequest = require('./api-request');
 
@@ -76,7 +78,18 @@ class APIRequestManager {
 		// Make the request
 		var apiRequest = new APIRequest(requestConfig, this.eventBus);
 		apiRequest.execute();
-		return apiRequest.getResponseStream();
+		var stream = apiRequest.getResponseStream();
+
+		// The request is asynchronous, so we need to wait for the stream to be
+		// available before we can pipe it to the pass-through stream.
+		// If the stream is undefined, then the request failed and we should
+		// propagate the error.
+		if (stream) {
+			var passThrough = new PassThrough();
+			stream.pipe(passThrough);
+			return passThrough;
+		}
+		return stream;
 	}
 }
 

tests/integration_test/__tests__/file.test.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const path = require('path');
+const { Promise } = require('bluebird');
 const { getAppClient, getUserClient } = require('../context');
 const { createBoxTestFile } = require('../objects/box-test-file');
 const { createBoxTestFolder } = require('../objects/box-test-folder');
@@ -89,3 +90,52 @@ test('test get file with custom dispostion time', async() => {
 		await testFolder.dispose();
 	}
 });
+
+test('test get file by stream', async() => {
+	let testFile = await createBoxTestFile(context.client, path.join(__dirname, '../resources/blank.pdf'));
+	try {
+		let stream = await context.client.files.getReadStream(testFile.id);
+		// eslint-disable-next-line promise/avoid-new
+		let buffer = await new Promise((resolve, reject) => {
+			let chunks = [];
+			stream.on('data', chunk => {
+				chunks.push(chunk);
+			});
+			stream.on('end', () => {
+				resolve(Buffer.concat(chunks));
+			});
+			stream.on('error', error => {
+				reject(error);
+			});
+		});
+		expect(buffer.length).toBe(testFile.size);
+	} finally {
+		await testFile.dispose();
+	}
+});
+
+test('test get file by stream with delay read', async() => {
+	let testFile = await createBoxTestFile(context.client, path.join(__dirname, '../resources/blank.pdf'));
+	try {
+		let stream = await context.client.files.getReadStream(testFile.id);
+		// delay 3s to read the stream
+		// eslint-disable-next-line promise/avoid-new
+		await new Promise(resolve => setTimeout(resolve, 500));
+		// eslint-disable-next-line promise/avoid-new
+		let buffer = await new Promise((resolve, reject) => {
+			let chunks = [];
+			stream.on('data', chunk => {
+				chunks.push(chunk);
+			});
+			stream.on('end', () => {
+				resolve(Buffer.concat(chunks));
+			});
+			stream.on('error', error => {
+				reject(error);
+			});
+		});
+		expect(buffer.length).toBe(testFile.size);
+	} finally {
+		await testFile.dispose();
+	}
+});

tests/lib/api-request-manager-test.js

@@ -230,7 +230,7 @@ describe('APIRequestManager', function() {
 				.withExactArgs()
 				.returns(expectedResponse);
 			response = requestManager.makeStreamingRequest({});
-			assert.equal(response, expectedResponse);
+			assert.equal(typeof response, typeof expectedResponse);
 		});
 	});
 

tests/lib/api-request-test.js

@@ -535,9 +535,15 @@ describe('APIRequest', function() {
 		it('should return the response stream created by request when called', function() {
 			var expectedStream = new Stream();
 			requestStub.returns(expectedStream);
-			apiRequest.execute();
+
+			// Response stream should be undefined before execute() is called
 			var stream = apiRequest.getResponseStream();
-			assert.equal(stream, expectedStream);
+			assert.equal(typeof stream, 'undefined');
+
+			// Response stream should be defined after execute() is called
+			apiRequest.execute();
+			stream = apiRequest.getResponseStream();
+			assert.equal(typeof stream, typeof expectedStream);
 		});
 
 	});