node-kafka/CONTRIBUTING.md

Contributing to node-rdkafka

👍🎉 First off, thanks for taking the time to contribute! 🎉👍

The following is a set of guidelines for contributing to node-rdkafka which is hosted in the Blizzard Organization on GitHub. This document lists rules, guidelines, and help getting started, so if you feel something is missing feel free to send a pull request.

Table Of Contents

What should I know before I get started?

• Contributor Agreement

How Can I Contribute?

• Reporting Bugs
• Suggesting Enhancements
• Pull Requests

Styleguides

• Git Commit Messages
• JavaScript Styleguide
• C++ Styleguide
• Specs Styleguide
• Documentation Styleguide

Debugging

• Debugging C++

What should I know before I get started?

Contributor Agreement

Not currently required.

How can I contribute?

Reporting Bugs

Please use Github Issues to report bugs. When filling out an issue report, make sure to copy any related code and stack traces so we can properly debug. We need to be able to reproduce a failing test to be able to fix your issue most of the time, so a custom written failing test is very helpful.

Please also note the Kafka broker version that you are using and how many replicas, partitions, and brokers you are connecting to, because some issues might be related to Kafka. A list of librdkafka configuration key-value pairs also helps.

Suggesting Enhancements

Please use Github Issues to suggest enhancements. We are happy to consider any extra functionality or features to the library, as long as they add real and related value to users. Describing your use case and why such an addition helps the user base can help guide the decision to implement it into the library's core.

Pull Requests

• Include new test cases (either end-to-end or unit tests) with your change.
• Follow our style guides.
• Make sure all tests are still passing and the linter does not report any issues.
• End files with a new line.
• Document the new code in the comments (if it is JavaScript) so the documentation generator can update the reference documentation.
• Avoid platform-dependent code.
  Note: If making modifications to the underlying C++, please use built-in precompiler directives to detect such platform specificities. Use Nan whenever possible to abstract node/v8 version incompatibility.
• Make sure your branch is up to date and rebased.
• Squash extraneous commits unless their history truly adds value to the library.

Styleguides

General style guidelines

Download the EditorConfig plugin for your preferred text editor to automate the application of the following guidelines:

• Use 2-space indent (no tabs).
• Do not leave trailing whitespace on lines.
• Files should end with a final newline.

Also, adhere to the following not enforced by EditorConfig:

• Limit lines to 80 characters in length. A few extra (<= 5) is fine if it helps readability, use good judgement.
• Use lf line endings. (git's core.autocrlf setting can help)

Git Commit Messages

Commit messages should adhere to the guidelines in tpope's A Note About Git Commit Messages

In short:

• Use the imperative mood. ("Fix bug", not "Fixed bug" or "Fixes bug")
• Limit the first line to 50 characters or less, followed by a blank line and detail paragraphs (limit detail lines to about 72 characters).
• Reference issue numbers or pull requests whenever possible.

JavaScript Styleguide

• Place module.exports at or near the top of the file.
  • Defined functions are hoisted, so it is appropriate to define the function after you export it.
  • When exporting an object, define it first, then export it, and then add methods or properties.
• Do not use ES2015 specific features (for example, do not use let, const, or class).
• All callbacks should follow the standard Node.js callback signature.
• Your JavaScript should properly pass the linter (make jslint).

C++ Styleguide

• Class member variables should be prefixed with m_.
• Use a comment when pointer ownership has changed hands.
• Your C++ should properly pass the cpplint.py in the make lint test.

Specs Styleguide

• Write all JavaScript tests by using the mocha testing framework.
• All mocha tests should use exports syntax.
• All mocha test files should be suffixed with .spec.js instead of .js.
• Unit tests should mirror the JavaScript files they test (for example, lib/client.js is tested in test/client.spec.js).
• Unit tests should have no outside service dependencies. Any time a dependency, like Kafka, exists, you should create an end-to-end test.
• You may mock a connection in a unit test if it is reliably similar to its real variant.

Documentation Styleguide

• Write all JavaScript documentation in jsdoc-compatible inline comments.
• Each docblock should have references to return types and parameters. If an object is a parameter, you should also document any required subproperties.
• Use @see to reference similar pieces of code.
• Use comments to document your code when its intent may be difficult to understand.
• All documentation outside of the code should be in Github-compatible markdown.
• Make good use of font variations like bold and italics.
• Use headers and tables of contents when they make sense.

Editor

I began using Visual Studio code to develop on node-rdkafka. If you use it you can configure the C++ plugin to resolve the paths needed to inform your intellisense. This is the config file I am using on a mac to resolve the required paths:

c_cpp_properties.json

{
    "configurations": [
        {
            "name": "Mac",
            "includePath": [
                "${workspaceFolder}/**",
                "${workspaceFolder}",
                "${workspaceFolder}/src",
                "${workspaceFolder}/node_modules/nan",
                "${workspaceFolder}/deps/librdkafka/src",
                "${workspaceFolder}/deps/librdkafka/src-cpp",
                "/usr/local/include/node",
                "/usr/local/include/node/uv"
            ],
            "defines": [],
            "macFrameworkPath": [
                "/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks"
            ],
            "compilerPath": "/usr/bin/clang",
            "cStandard": "c11",
            "cppStandard": "c++17",
            "intelliSenseMode": "clang-x64"
        }
    ],
    "version": 4
}

Debugging

Debugging C++

Use gdb for debugging (as shown in the following example).

node-gyp rebuild --debug

gdb node
(gdb) set args "path/to/file.js"
(gdb) run
[output here]

You can add breakpoints and so on after that.