rspec-fundamentals

RSpec is a BDD testing framework for Ruby that uses describe, context, and it blocks to organize tests. Install the gem, run `rspec --init` to generate configuration files, and configure your spec_helper.rb to load dependencies and set up test environments.

Describe blocks group related tests by class or method. Context blocks organize tests by a specific condition or state within a describe block. It blocks define individual test cases that run assertions using expect statements and matchers.

Let defines reusable test variables that are evaluated lazily before each test runs. Use `let(:variable) { value }` to create a variable accessible throughout your describe or context block, reducing duplication and improving test readability.

Matchers are assertions that validate behavior in expect statements. Core matchers include `eq`, `be`, `include`, and `raise_error`. Combine them with expect to write readable assertions like `expect(object).to eq(value)` or `expect { code }.to raise_error`.

Yes, RSpec integrates with CI systems by running `rspec` in your build pipeline to generate test reports. Configure formatters like `--format documentation` and `--format json` to produce output that CI tools parse for pass/fail status and metrics.

No, basic matchers work with real objects and values. Mocking and doubles are optional techniques for isolating units of code. Start with core matchers like `eq` and `include`, then introduce doubles when tests require controlling external dependencies.