Napa.js core modules development guideline

Summary

A Napa.js core module is a module that provided by Napa.js and initialized ready for use in a Napa zone.

There are 2 types of core modules:

• Napa API core modules: A set of Napa.js specific modules that described in Napa.js modules.

• Node API core modules: A set of Napa.js modules that implement a subset of Node.js modules.

All core modules can be imported by using global function require(<module-name>) in napa zone. If a module is a built-in module, it is already loaded and can be accessed by its name as a global object.

Core modules index

Header file /src/module/core-modules/core-modules.h lists all native core modules to export.

JSON file /lib/core/core-modules.json lists all core modules available in Napa zone.

Napa API core modules

Napa API core modules are implemented in C++ and Typescript.

C++ implementation goes to folder /src/module/core-modules/napa. File /src/module/core-modules/napa/napa-binding.cpp is the entry of native boundary.

Typescript implementation goes to folder /lib. It uses process.binding() to access binary core modules and exports whatever defined in API document. File /lib/index.ts is the entry of javascript boundary.

Node API core modules

Napa API core modules are implemented in C++ and Typescript.

C++ implementation goes to folder /src/module/core-modules/node.

Typescript implementation goes to folder /lib/core. It uses process.binding() to access binary core modules and exports whatever defined in API document.

Developing guideline

• To add a pure native module, follow the following steps:

  • Create a module class in the correct folder (see above) with a static Init() method.
  • Add the class to the list in /src/module/core-modules/core-modules.h.
  • Add the module name in /lib/core/core-modules.json.

• To add a pure typescript/javascript Node API module, follow the following steps:

  • Add files under folder /lib/core.
  • Update file /lib/core/.gitignore if any javascript file added under folder /lib/core.
  • Add the module name in /lib/core/core-modules.json.

• To add a native/js mixed Node API module, follow the steps of both as described above. Use process.binding() to access binary core modules in typescript/javascript.

• To add a Napa API module usually means a big change to existing structure. May need a design review.

• Try to always use typescript rather than javascript. Use javascript only when leveraging an existing javascript implementation.

• Node API modules should be tested in Napa zone, and Napa API modules should be tested in both Node and Napa zone.

• Pure native test goes to /unittest (Using Catch) and js test goes to /test (Using mocha).