@percy/config

What is @percy/config?

@percy/config is a configuration management package for Percy, a visual testing and review platform. It allows users to define and manage configuration settings for Percy in a structured and programmatic way.

What are @percy/config's main functionalities?

Load Configuration

This feature allows you to load the configuration settings for Percy from a configuration file. The `load` function reads the configuration and returns it as a JavaScript object.

const { load } = require('@percy/config');
const config = load();
console.log(config);

Validate Configuration

This feature allows you to validate a given configuration object against the expected schema. The `validate` function returns an object indicating whether the configuration is valid and any errors if it is not.

const { validate } = require('@percy/config');
const config = { version: 2, snapshots: { widths: [375, 1280] } };
const { valid, errors } = validate(config);
console.log(valid, errors);

Merge Configuration

This feature allows you to merge multiple configuration objects into one. The `merge` function takes two or more configuration objects and combines them, with later objects overriding earlier ones.

const { merge } = require('@percy/config');
const baseConfig = { version: 2, snapshots: { widths: [375] } };
const overrideConfig = { snapshots: { widths: [1280] } };
const mergedConfig = merge(baseConfig, overrideConfig);
console.log(mergedConfig);

Other packages similar to @percy/config

config

The `config` package is a configuration management tool for Node.js applications. It allows you to define configuration settings for different environments and load them dynamically. Compared to @percy/config, it is more general-purpose and not specific to visual testing.

convict

The `convict` package provides a way to define a schema for your configuration files and validate them. It also supports environment-specific configurations and type validation. While @percy/config is tailored for Percy, `convict` is more flexible and can be used in various types of applications.

dotenv

The `dotenv` package loads environment variables from a `.env` file into `process.env`. It is simpler and more lightweight compared to @percy/config, focusing on environment variable management rather than structured configuration schemas.

README

@percy/config

Handles loading and adding options to Percy configuration files. Uses cosmiconfig to load configuration files and JSON schema with AJV to validate those configuration files.

Usage

Loading config files

The .load() method will load and validate a configuation file, optionally merging it with any provided overrides. If no path is provided, will search for the first supported config found from the current directory up to the home directoy. Configuration files are cached and reused unless reload is true.

import PercyConfig from '@percy/config'

// loading is done synchronously
const config = PercyConfig.load({
  path,            // config file path or directory path containing a config file
  overrides = {},  // configuration option overrides
  reload = false,  // reload file and update cache
  bail = false     // return undefined on validation warnings
})

Supported files

• "percy" entry in package.json
• .percyrc YAML or JSON file
• .percy.json JSON file
• .percy.yaml or .percy.yml YAML file
• .percy.js or percy.config.js file that exports an object

Extending config options

The .addSchema() function will add a sub-schema to the Percy configuration file which will be parsed and validated when PercyConfig.load() is called. See JSON schema for possible schema options.

import PercyConfig from '@percy/config'

PercyConfig.addSchema({ propertyName: JSONSchema })