@emitty/core

A platform for finding dependencies between files and building tools for incremental compilation or build.

Table of Contents

• Highlights
• Donation
• Installation
• API
  • .configure
  • .language
  • .load
  • .dump
  • .clear
  • .filter
• Options
  • cwd
  • fs
• FAQ
  • How does it works?
  • How to use this with gulp?
  • How to add my own language?
• Changelog
• License

Highlights

• Simple and configurable.
• Language free.
• Support snapshots for postpone incremental builds.

Donation

Do you like this project? Support it by donating, creating an issue or pull request.

Installation

npm install @emitty/core

Usage

const emitty = require('@emitty/core').configure();

emitty.language({
    extensions: ['.pug', '.jade'],
    parser: require('@emitty/language-pug').parse
});

await emitty.filter('home.png'); // true
await emitty.filter('home.png', 'news.png'); // false

API

.configure([options])

Returns an Emitty instance with the methods described below.

[options]

• Required: false
• Type: Options

See Options section.

.language(specification)

Adds language support.

specification

• Required: true
• Type: Language

Specification of the language to be added.

:1234: How to add my own language?

export type Language = {
    extensions: string[]; // ['.pug', '.jade']
    parser: (filepath: string, buffer: Buffer) => { references: string[] };
};

.load(snapshot)

Loads information from the snapshot to the storage.

snapshot

• Required: true
• Type: Snapshot

Snapshot storage.

.dump()

Returns an object that contains a storage in the snapshot format.

.clear()

Completely cleans the storage.

.filter(source, [changed])

Determines whether to compile the changed file if it is passed.

:1234: How does it works?

source

• Required: true
• Type: string

The file that is currently being processed by the builder or compiler.

[changed]

• Required: false
• Type: string

The file that trigger the build or compile.

Options

cwd

• Type: string
• Default: process.cwd()

The current working directory.

fs

• Type: FileSystemAdapter
• Default: fs.*

Custom implementation of methods for working with the file system.

export type FileSystemAdapter = {
    access?: typeof fs.access;
    constants?: typeof fs.constants;
    readFile?: typeof fs.readFile;
};

FAQ

How does it works?

The .configure method initiates a storage to which all relationships between the files being processed are later written.

When you call the .filter method without the changed file, @emitty reads the source file and builds a dependency tree for that file (with recursive reads of dependencies). In this case, the filter always returns true to ensure that all files in the project are compiled and collected in the storage.

When you call the .filter method with the changed file, @emitty reads only the changed file and updates its dependencies (without recursive reads of dependencies). In this case, the filter returns true if there is a reference to the changed file in the dependency tree of the source file. Otherwise false.

How to use this with gulp?

Look at the gulp.js file for an example.

How to add my own language?

You can use the .language method with any language, even your own. Just implement the parser for your language.

type File = {
    references: string[];
};

export function myOwnLanguageParser(filepath: string, buffer: Buffer): Promise<File> {
    return Promise.resolve({
        references: ['home.own.language', 'components/header.own.language']
    });
}

Next, just use it with the .language method.

Changelog

See the Releases section of our GitHub project for changelog for each release version.

License

This software is released under the terms of the MIT license.