Let's get acquainted!

Let's get acquainted!

First Name:	Azat
Last Name:	Davliatshin
Experience:	9 years in JS development Life Science & Healthcare
Expertise:	FE, BE, Clouds, Mobile, Legacy
Criminal Records:	Had to force push changes into production branch

Agenda

Agenda

• The task definition
• Straightforward solution: pros and cons
• Maintainability <- QA <- ASR
• Maintainability Tactics
• Design
• Tools

The task definition

Straightforward solution

import { json2csv } from 'json-2-csv';
import { PutObjectCommand, S3Client } from "@aws-sdk/client-s3";

const urlAPI = "...";
const tokenAPI = "...";
const options = {
	headers: '' // use tokenAPI
};

const fetchResponse = await fetch(urlAPI, options);
const data = fetchResponse.json();

const csv = await converter.json2csv(data);

const client = new S3Client({});
const command = new PutObjectCommand({});
await client.send(command);
							

import { json2csv } from 'json-2-csv';
import { PutObjectCommand, S3Client } from "@aws-sdk/client-s3";

const urlAPI = "...";
const tokenAPI = "...";
const options = {
	headers: '' // use tokenAPI
};

const fetchResponse = await fetch(urlAPI, options);
const data = fetchResponse.json();

const csv = await converter.json2csv(data);

const client = new S3Client({});
const command = new PutObjectCommand({});
await client.send(command);
							

import { json2csv } from 'json-2-csv';
import { PutObjectCommand, S3Client } from "@aws-sdk/client-s3";

const urlAPI = "...";
const tokenAPI = "...";
const options = {
	headers: '' // use tokenAPI
};

const fetchResponse = await fetch(urlAPI, options);
const data = fetchResponse.json();

const csv = await converter.json2csv(data);

const client = new S3Client({});
const command = new PutObjectCommand({});
await client.send(command);
							

Change request is time consuming

							import { json2csv } from 'json-2-csv';
...
// This package is deprecated, it should be replaced
const csv = await converter.json2csv(data);
...

						

Code duplication

Additional functionality request: launch task manually from UI, there are options for storages

Poor errors handling

							try {
...
}
catch (exception) {
	//TODO: try to understand what exactly throws this exception
}

						

Solution is not maintainable

Maintainability

ASR

Architecturally significant requirements

ASR

QA

Quality attributes

QA

A QUALITY ATTIRBUTE (QA) is a measurable or testable property of a system that is used to indicate how well the system satisfies the needs of its stakeholders

QA

• Performance
• Security
• Scalability
• Availability
• Reliability
• Usability
• Maintainability
• ...

Maintainability

Maintainability

QA deals with change and the cost in time or money of making a change, including the extent to which this modification affects other functions or quality attributes.

Maintainability Tactics

Maintainability Tactics

Defer Binding

							//no magic values! ❌ 🧙 🔤
const urlAPI = "...";
const tokenAPI = "...";

// much better :) ✅ 
const urlAPI = process.env.managementToolApiUrl;
const tokenAPI = process.env.token;

Split the code

							// API
const fetchResponse = await fetch(urlAPI, options);
const data = fetchResponse.json();

// Converter
const csv = await converter.json2csv(data);

// Storage
const client = new S3Client({});
const command = new PutObjectCommand({});
await client.send(command);

Cohesion & Coupling

Design

"Tools"

Development Guidelines

Static code analysis

• ESLint
• Prettier
• SonarQube
• ...
• Typescript*

Tests

Tests