feat: add node sample for cloud composer tutorial (GoogleCloudPlatform#1708)

* feat: add node sample for cloud composer tutorial

Author: sofisl

CODEOWNERS

@@ -27,6 +27,8 @@ datastore/functions @benwhitehead
 
 # One-offs
 cloud-sql @kurtisvg
+composer @leahecole @sofisl
 healthcare @noerog
 iot @gguuss
 jobs @happyhuman
+

composer/README.md

@@ -0,0 +1,9 @@
+# [Node sample for Cloud Composer-Dataflow Tutorial][tutorial-link]
+
+This is the code for the transform CSV-to-JSON code sample for the [Using the DataflowTemplateOperator][tutorial-link] tutorial.
+
+This tutorial shows how to use the DataflowTemplateOperator to launch Dataflow Pipelines from Cloud Composer. The Cloud Storage Text to BigQuery (Stream) pipeline is a streaming pipeline that allows you to stream text files stored in Cloud Storage, transform them using a JavaScript User Defined Function (UDF) that you provide, and output the results to BigQuery. We'll use Cloud Composer to kick off a Cloud Dataflow pipeline that will apply the User-Defined Function to our .txt file and format it according to the JSON schema.
+
+The code held in this repo is a User Defined Function written in JavaScript that will transform each line of a .txt file into the relevant columns for a BigQuery table.
+
+[tutorial-link]: https://cloud.devsite.corp.google.com/composer/docs/how-to/using/using-dataflow-template-operator?auto_signin=false

composer/composer_transform_csv_to_json.js

@@ -0,0 +1,46 @@
+/* eslint-disable func-style */
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+module.exports = function main(
+ line = 'tampa, 106, january, null, null, 08-17-2019'
+) {
+ // [START composer_transform_csv_to_json]
+
+ function transformCSVtoJSON(line) {
+ const values = line.split(',');
+ const properties = [
+ 'location',
+ 'average_temperature',
+ 'month',
+ 'inches_of_rain',
+ 'is_current',
+ 'latest_measurement',
+ ];
+ const weatherInCity = {};
+
+ for (let count = 0; count < values.length; count++) {
+ if (values[count] !== 'null') {
+ weatherInCity[properties[count]] = values[count];
+ }
+ }
+
+ const jsonString = JSON.stringify(weatherInCity);
+ return jsonString;
+ }
+
+ transformCSVtoJSON(line);
+ // [END composer_transform_csv_to_json]
+ return transformCSVtoJSON(line);
+};

composer/package.json

@@ -0,0 +1,22 @@
+{
+ "name": "nodejs-docs-samples-composer",
+ "description": "Node.js Google Composer sample.",
+ "version": "0.0.1",
+ "private": true,
+ "license": "Apache-2.0",
+ "author": "Google Inc.",
+ "repository": {
+ "type": "git",
+ "url": "https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git"
+ },
+ "engines": {
+ "node": ">=8.0.0"
+ },
+ "scripts": {
+ "test": "mocha --exit test/*.test.js"
+ },
+ "devDependencies": {
+ "chai": "^4.2.0",
+ "mocha": "^7.0.0"
+ }
+}

composer/test/composer_transform_csv_to_json.test.js

@@ -0,0 +1,14 @@
+const {assert} = require('chai');
+const tutorial = require('../composer_transform_csv_to_json.js');
+
+const lineTest = 'tampa, 106, january, null, null, 08-17-2019';
+
+it('should separate out a line and turn into a json string', () => {
+ const output = tutorial(lineTest);
+ assert.match(
+ output,
+ new RegExp(
+ '{"location":"tampa","average_temperature":" 106","month":" january","inches_of_rain":" null","is_current":" null","latest_measurement":" 08-17-2019"}'
+ )
+ );
+});