mytril/dist/utils/deep-merge.js

Mytril Svelte library component for rapidly building modern websites based on Svelte and Sveltekit

/**
 * Deeply merges two objects. The `source` object properties will overwrite the `target` object properties.
 * If a property value is an object, it will be recursively merged.
 * If a property value is a string or number, it will directly overwrite the `target` property.
 *
 * @param target - The target object to merge properties into.
 * @param source - The source object containing properties to merge into the target object.
 * @returns A new object with merged properties from both `target` and `source`.
 */
export const deepMerge = (target, source) => {
    const output = { ...target };
    if (source) {
        for (const key in source) {
            if (typeof source[key] === 'string' || typeof source[key] === 'number') {
                output[key] = source[key];
            }
            else {
                if (Object.prototype.hasOwnProperty.call(source, key)) {
                    if (output[key]) {
                        output[key] = {
                            ...(typeof output[key] === 'object' && output[key] !== null ? output[key] : {}),
                            ...(typeof source[key] === 'object' && source[key] !== null ? source[key] : {})
                        };
                    }
                    else {
                        output[key] = source[key];
                    }
                }
            }
        }
    }
    return output;
};