marys
41 lines
1.0 KiB
JavaScript
41 lines
1.0 KiB
JavaScript
/**
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* Test if a value is a plain object.
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* @param {*} val - A value.
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* @return {boolean} true if `val` is a plain object.
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*/
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const isObject = val =>
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val != null && typeof val === 'object' && Array.isArray(val) === false;
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/**
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* Apply a JSON merge patch. The origin is *not* modified, but unchanged
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* properties will be recycled.
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*
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* @param {*} origin - The value to patch.
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* @param {*} patch - An [RFC 7396](https://tools.ietf.org/html/rfc7396) patch.
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* @return {*} The patched value.
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*/
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export function apply(origin, patch) {
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if (!isObject(patch)) {
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// If the patch is not an object, it replaces the origin.
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return patch;
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}
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const result = !isObject(origin)
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? // Non objects are being replaced.
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{}
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: // Make sure we never modify the origin.
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Object.assign({}, origin);
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Object.keys(patch).forEach(key => {
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const patchVal = patch[key];
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if (patchVal === null) {
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delete result[key];
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} else {
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result[key] = apply(result[key], patchVal);
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}
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});
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return result;
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}
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export default apply;
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