Tests

Jest Best Practices

Practical guidelines for writing fast, reliable, and maintainable Jest test suites that catch real bugs without becoming brittle.

Parameterized Tests with test.each()

Learn how to use Jest's test.each() and describe.each() to run the same test logic against multiple input/output pairs without duplicating code.

Running and Watching Tests

How to run Jest from the command line, use watch mode for fast feedback, and interpret coverage output.

Selenium Best Practices

Practical habits — stable locators, explicit waits, Page Object Model, and isolated test data — that turn a flaky Selenium suite into a dependable one.

Cypress Best Practices

A practical guide to writing Cypress tests that are fast, resilient to UI changes, and free of the flakiness that erodes trust in a test suite.

Debugging Cypress Tests

Learn the practical toolkit for debugging failing or flaky Cypress tests — from time-travel debugging and the Command Log to browser DevTools and cy.debug().

Handling Authentication in Tests

Learn how to bypass slow UI logins with programmatic authentication and cy.session() caching, and how to handle third-party SSO safely.

Custom Data Tests

When the four built-in generic tests aren't enough, dbt lets you write singular tests as standalone SQL files or custom generic tests as reusable, parameterize…

Schema Tests

Schema tests are YAML-declared assertions — unique, not_null, accepted_values, and relationships — that dbt compiles into SQL to automatically validate your da…

Testing Erlang with EUnit

Learn how to write, organize, and run unit tests for Erlang code using the built-in EUnit framework.

Flaky Tests and How to Fix Them

Learn what makes automated tests flaky, how to systematically diagnose the root cause, and proven techniques to make your test suite deterministic and trustwor…

Parameterized Tests

Learn how to replace repetitive, copy-pasted test cases with data-driven parameterized tests that scale to cover many inputs cleanly.

Refactoring Safely with Tests

Understand why a solid test suite is what makes structural code changes safe, and how to build one for legacy code that has none.

Types of Tests: Unit, Integration, and End-to-End

A practical breakdown of unit, integration, and end-to-end tests -- what each one verifies, when to use it, and how to tell them apart.

Writing Good Unit Tests

Learn what separates a fast, trustworthy unit test from a brittle one, and the core principles (FIRST, AAA) that guide good test design.

Writing Integration Tests

Learn how to test the way multiple units of your system work together, catching bugs that unit tests miss at the boundaries between modules, services, and infr…

Common CI/CD Pitfalls

A survey of recurring mistakes teams make when building CI/CD pipelines — from flaky tests to secret leakage — and the practical fixes for each.

Running Automated Tests in CI/CD

How CI pipelines execute unit, integration, and end-to-end tests automatically, and the design choices — parallelism, flakiness handling, test selection — that…

Go Testing Cheat Sheet

Covers writing unit tests and table-driven tests with the testing package, subtests, benchmarks, and running tests with the go test CLI.