time-to-botec/squiggle/node_modules/@stdlib/utils/merge/lib/mergefcn.js

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/**
* @license Apache-2.0
*
* Copyright (c) 2018 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
'use strict';
// MODULES //
var isObject = require( '@stdlib/assert/is-object' );
var deepMerge = require( './deepmerge.js' );
// MAIN //
/**
* Returns a merge function based on provided options.
*
* @private
* @param {Options} opts - function options
* @param {number} options.level - merge level
* @param {boolean} options.copy - boolean indicating whether to deep copy merged values
* @param {(boolean|Function)} options.override - defines the merge strategy
* @param {boolean} options.extend - boolean indicating whether new properties can be added to the target object
* @returns {Function} merge function
*
* @example
* var merge = mergefcn({
* 'level': Number.POSITIVE_INFINITY,
* 'copy': true,
* 'override': true,
* 'extend': true
* });
* // returns <Function>
*/
function mergefcn( opts ) {
return merge;
/**
* Merges objects into a target object. Note that the target object is mutated.
*
* @private
* @param {Object} target - target object
* @param {...Object} source - source objects (i.e., objects to be merged into the target object)
* @throws {Error} must provide a target object and one or more source objects
* @throws {TypeError} first argument must be an object
* @throws {TypeError} source arguments must be objects
* @returns {Object} merged (target) object
*
* @example
* var target = {
* 'a': 'beep'
* };
* var source = {
* 'a': 'boop',
* 'b': 'bap'
* };
*
* var out = merge( target, source );
* // returns {'a':'boop', 'b':'bap'}
*/
function merge( target ) {
var nargs;
var arg;
var src;
var i;
nargs = arguments.length - 1;
if ( nargs < 1 ) {
throw new Error( 'insufficient input arguments. Must provide both a target object and one or more source objects.' );
}
if ( !isObject( target ) ) {
throw new TypeError( 'invalid argument. First argument must be an object. Value: `' + target + '`.' );
}
src = new Array( nargs );
for ( i = 0; i < nargs; i++ ) {
arg = arguments[ i+1 ];
// WARNING: this is a porous check. Buffers, Numbers, Booleans, Strings, Dates, RegExp, custom class instances,... will all pass.
if ( !isObject( arg ) ) {
throw new TypeError( 'invalid argument. A merge source must be an object. Value: `' + arg + '`.' );
}
src[ i ] = arg;
}
for ( i = 0; i < nargs; i++ ) {
deepMerge( target, src[ i ], opts.level, opts.copy, opts.override, opts.extend ); // eslint-disable-line max-len
}
return target;
}
}
// EXPORTS //
module.exports = mergefcn;