create a SCIM patch request body based on diff between Javascript objects.

ScimPatch.js

import isEqual from "lodash/isEqual";
import isObject from "lodash/isObject";

const flattenPaths = (value, path = []) => {
  if (!isObject(value)) {
    return { [path.join(".")]: value };
  }
  if (Array.isArray(value)) {
    return value.reduce((cumulative, item) => {
      cumulative[`${path.join(".")}[value eq "${item.value}"]`] = item;
      return cumulative;
    }, {});
  }
  return Object.keys(value).reduce((cumulative, key) => {
    return {
      ...cumulative,
      ...flattenPaths(value[key], [...path, key])
    };
  }, {});
};

const getOperationsMap = (flattenedObject, flattenedBase, op) => {
  return Object.keys(flattenedObject).reduce((operationsMap, path) => {
    const value = flattenedObject[path];

    if (!isEqual(value, flattenedBase[path])) {
      const operation = {
        path,
        op: flattenedBase[path] == null ? op : "replace"
      };

      if (operation.op !== "remove") {
        operation.value = value;
      }

      const addArrayBeginIndex =
        operation.op === "add" ? path.indexOf("[") : -1;

      if (addArrayBeginIndex === -1) {
        operationsMap[path] = operation;
      } else {
        const addPath = path.substring(0, addArrayBeginIndex);

        if (operationsMap[addPath] == null) {
          operation.path = addPath;
          operation.value = [operation.value];
          operationsMap[addPath] = operation;
        } else {
          operationsMap[addPath].value.push(operation.value);
        }
      }
    }
    return operationsMap;
  }, {});
};

export default class ScimPatch {
  constructor(patched, original = {}) {
    const flatPatched = flattenPaths(patched);
    const flatOriginal = flattenPaths(original);

    const removals = getOperationsMap(flatOriginal, flatPatched, "remove");
    const additions = getOperationsMap(flatPatched, flatOriginal, "add");

    this.schemas = ["urn:ietf:params:scim:api:messages:2.0:PatchOp"];
    this.Operations = Object.values({ ...removals, ...additions });
  }
}