Testing & Quality Assurance glossary: terms explained simply

A

Automated Regression Testing

The re-execution of previously passed test suites following code mutations to ensure newly deployed changes have not broken existing functionality.

Intermediate

B

Build Verification Smoke Testing SmokeTest

A preliminary suite of fast, non-exhaustive tests verifying that critical system functions operate before initiating comprehensive test suites.

Intermediate

C

Code Coverage Instrumentation Code Coverage Instrumentation & Metrics · CodeCoverage

A metric quantifying the proportion of source code branches, lines, and statements executed during automated test suite runs.

Intermediate

Consumer-Driven Contract Testing Consumer-Driven Contract Testing · Pact

A testing technique verifying that collaborating microservices agree upon interface schemas and response payloads without spinning up integrated environments.

Advanced

E

End-to-End Testing (E2E) End-to-End Testing · E2E

A software verification technique simulating complete real-world user journeys across the entire stack from the browser UI down to backend databases.

Intermediate

F

Flaky Test Detection and Quarantine Flaky Test Mitigation & Quarantine · FlakyTest

Strategies for diagnosing and resolving non-deterministic tests that alternate between passing and failing outcomes without any underlying code modifications.

Advanced

Fuzz Testing (Fuzzing) Fuzzing Security & Robustness Testing

An automated security and stability testing technique that feeds malformed, random, and invalid data inputs into software to trigger buffer overflows and crashes.

Advanced

L

Load and Stress Testing Load, Stress & Spike Testing · k6 · LoadTest

Performance benchmarking simulating thousands of concurrent virtual users to evaluate server capacity, latency thresholds, and system breaking points.

Intermediate

M

Mutation Testing Mutation Testing · Stryker

An advanced testing technique that evaluates test suite quality by programmatically injecting intentional faults (mutants) into source code.

Advanced

P

Property-Based Testing (PBT) Property-Based Testing · QuickCheck

A testing methodology where universal properties and behavioral invariants are specified, and automated fuzz generators feed thousands of randomized edge-case inputs.

Advanced

S

Static Code Analysis (SAST) Static Application Security Testing · SonarQube

Automated examination of application source code without execution, detecting coding bugs, anti-patterns, and security vulnerabilities early.

Intermediate

Synthetic Monitoring and Health Checks Synthetic Monitoring & Health Check · SyntheticCheck

A proactive monitoring technique simulating automated user transactions at scheduled intervals to detect outages and latency before actual customers are affected.

Intermediate

T

Test Doubles (Mocks, Stubs, Spies) Test Doubles · Mocks, Stubs & Spies · Mocks/Stubs

Simulated objects and functions replacing real dependencies (payment processors, SMS gateways) to isolate units under test safely.

Intermediate

Test-Driven Development (TDD) Test-Driven Development · TDD

A software engineering practice following the Red-Green-Refactor cycle: writing a failing test first, implementing minimal code to pass, and refactoring.

Intermediate

U

UI Snapshot & Visual Regression Testing SnapshotTest

A verification approach comparing rendered component markup or visual pixel screenshots against approved baseline references to catch unintended UI drifts.

Intermediate