# Node.js Core Tests This directory contains code and data used to test the Node.js implementation. For a detailed guide on how to write tests in this directory, see [the guide on writing tests](../doc/guides/writing-tests.md). On how to run tests in this directory, see [the contributing guide](../doc/guides/contributing/pull-requests.md#step-6-test). ## Test Directories |Directory |Runs on CI |Purpose | |-------------------|---------------|---------------| |abort |Yes |Tests for when the ``` --abort-on-uncaught-exception ``` flag is used.| |addons |Yes |Tests for [addon](https://nodejs.org/api/addons.html) functionality along with some tests that require an addon to function properly.| |cctest |Yes |C++ test that is run as part of the build process.| |common | |Common modules shared among many tests. [Documentation](./common/README.md)| |es-module |Yes |Test ESM module loading.| |fixtures | |Test fixtures used in various tests throughout the test suite.| |gc |No |Tests for garbage collection related functionality.| |internet |No |Tests that make real outbound connections (mainly networking related modules). Tests for networking related modules may also be present in other directories, but those tests do not make outbound connections.| |known_issues |Yes |Tests reproducing known issues within the system. All tests inside of this directory are expected to fail consistently. If a test doesn't fail on certain platforms, those should be skipped via `known_issues.status`.| |message |Yes |Tests for messages that are output for various conditions (```console.log```, error messages etc.)| |parallel |Yes |Various tests that are able to be run in parallel.| |pseudo-tty |Yes |Tests that require stdin/stdout/stderr to be a TTY.| |pummel |No |Various tests for various modules / system functionality operating under load.| |sequential |Yes |Various tests that are run sequentially.| |testpy | |Test configuration utility used by various test suites.| |tick-processor |No |Tests for the V8 tick processor integration. The tests are for the logic in ```lib/internal/v8_prof_processor.js``` and ```lib/internal/v8_prof_polyfill.js```. The tests confirm that the profile processor packages the correct set of scripts from V8 and introduces the correct platform specific logic.| |timers |No |Tests for [timing utilities](https://nodejs.org/api/timers.html) (```setTimeout``` and ```setInterval```).| _When a new test directory is added, make sure to update the `CI_JS_SUITES` variable in the `Makefile` and the `js_test_suites` variable in `vcbuild.bat`._