Testing is an integral part of the application development life cycle. As a tech professional with over 12 years of experience in test automation across various domains, I cannot emphasize enough the importance of testing early and testing comprehensively. The cost of finding and fixing defects grows exponentially if they reach production. In today‘s extremely competitive software market, with consumers less forgiving of flaws and willing to switch solutions, the bar for quality is higher.
This article aims to provide a detailed guide into different types of testing performed on applications, highlighting the purpose each test type serves, methodologies used, metrics tracked and tools available to automate testing.
Importance of Testing
Let‘s first understand why exhaustive testing is indispensable, before digging into specifics:
Ensures intended functionality: Systematic testing verifies all features and user workflows function per specifications
Optimizes additional quality attributes: Performance, security, reliability testing ensures smooth, uninterrupted user experience
Catches defects early: Nipping issues during development using unit testing, integration testing costs 10-100x less than in production
Reduces business risk: Releasing error-prone unstable software leads to customer attrition and revenue losses
Enables usage telemetry: Production telemetry coupled with test analytics provides data to enhance software iteratively
Thorough testing is hence crucial for creating future-proof high quality applications.
Categorization of Tests
Broadly testing can be classified into:
Functional Testing
Evaluates logical functioning of the software components and their integration. Ensures adherence to requirements. Categorized based on system hierarchy level under test:
- Unit Testing – Tests individual code units in isolation
- Integration Testing – Tests interactions between code units
- System Testing – Tests entire integrated system
Non-Functional Testing
Examines non-functional quality attributes regarding operational parameters and user experience:
- Performance – Speed, scalability, stability under load
- Security – Identification of vulnerabilities to threats
- Reliability – Consistency of operation over time
- Usability – Human interaction experience
- Compatibility – Operation across environments
- Other aspects – Installability, recoverability, maintainability
Many other sub-types exist within these too. Let‘s explore them now.
Functional Testing
This testing focuses purely on system functionality…
Unit Testing
Unit testing involves testing individual units of code in isolation…
The metrics tracked for unit tests include:
- Code coverage – measures the percentage of code exercised by tests
- Branch coverage – checks test coverage for conditional branches
- Data flow coverage – verifies usage of variables
Some popular tools used are:
- NUnit – open-source .NET unit testing framework
- JUnit – Java unit testing framework
- PHPUnit – PHP unit testing framework
Integration Testing
Integration testing checks combined operation of integrated modules/units…
It adopts a systematic strategy to combine units and test:
- Top-down approach – High level modules tested first
- Bottom-up approach – Low level units tested first
- Mixed approach – Bidirectional with cyclic dependencies
Tools like Selenium and TestNG help test and automate these scenarios.
The defect removal efficiency metric helps quantify integration testing rigor:
- DRE = (Defects before testing – Defects after testing)/Defects before testing
Higher DRE => better test effectiveness
System Testing
System testing involves testing the entire integrated system to validate stable operation across various real world scenarios like – stress, backup/recovery, failover etc.
Cucumber and Karma enable behavior driven automated checks at a system level.
Tracking system test cycle time helps assess predictability of testing activities…
Non-Functional Testing
This evaluates behavioral aspects regarding experience, performance etc…
Performance Testing
Different performance testing activities include:
- Load testing – checking operation under peak concurrent users
- Volume testing – handling high data volumes
- Stress testing – operation under heavy loads
Apache JMeter, LoadNinja provide a rich set of protocol based load generation capabilities for web, mobile and web service interfaces.
Response time and throughput metrics help benchmark server side throughput. Higher throughput and lower response time indicate better performance.
Resource utilization monitoring helps identify bottlenecks during load injection.
Security Testing
Different aspects evaluated under security testing include:
- Static Application Security Testing (SAST) – inspects code for vulnerabilities
- Dynamic Application Security Testing (DAST) – tests running systems for threats
- Vulnerability scanning
- Risk analysis
Tools like VeraCode perform SAST…
Importance of Testing
Some key benefits making testing indispensable:
Defect Prevention – x units tests save y defects in production
Reduced Risk – z% threat coverage reduces attack surface area
Optimized Quality – w% improvement in user retention/satisfaction
Conclusion
Elaborate testing is crucial to ensure well-rounded, resilient applications that exceed customer expectations. A multi-dimensional testing strategy identifies weaknesses early for timely remedy, leading to smooth user experience and fueling product popularity. Careful test planning considering areas outlined can help optimize testing efforts for efficiency.
