@quase/config

About

Provides utilities to get configuration (from a file or package.json), apply defaults and validate options.

import { getConfig, applyDefaults, t, validate, printError } from "@quase/config";

const schema = {
  foo: {
    type: "boolean",
    deprecated: true
  },
  bar: {
    type: "boolean",
    default: true
  },
  object: {
    type: t.object( {
      prop: {
        type: "number",
        example: 10
      }
    } )
  },
  tuple: {
    type: t.tuple( [
      {
        type: "string"
      },
      {
        type: "string"
      }
    ] )
  },
  array: {
    // Array of numbers
    type: t.array( {
      type: "number"
    } ),
    merge: "concat"
  },
  value: {
    choices: [ 0, 1, 2 ]
  }
};

const config = getConfig( {
  cwd: process.cwd(),
  configFiles: [],
  configKey: "",
  failIfNotFound: false
} );

const options = applyDefaults( schema, config ); // The first object passed (after schema) takes precedence

try {
  validate( schema, options );
} catch ( e ) {
  printError( e );
}

Merge mode

It is used to customize how values are merged when applying defaults and merging multiple objects.

• "override": Just sets the value without merging.
• "merge": If they are arrays, merge them.
• "concat": If they are arrays, just concats them.
• "spreadMeansConcat": If they are arrays, concat them when the value with higher precedence has "..." as its first element.
• You can also provide a function of the form ( obj, src ) => any.