fratzinger/feathers-utils

import { deepEqual as _isEqual } from "fast-equals";
import _get from "lodash/get.js";
import _set from "lodash/set.js";
import type { Path } from "../typesInternal";

export interface PushSetOptions {
  unique?: boolean;
}

/**
 * util to push a value to an array at a given path in an object
 */
export const pushSet = (
  obj: Record<string, unknown>,
  path: string | Path,
  val: unknown,
  options?: PushSetOptions,
): unknown[] => {
  options = options || {};
  let arr = _get(obj, path);
  if (!arr || !Array.isArray(arr)) {
    arr = [val];
    _set(obj, path, arr);
    return arr;
  } else {
    if (options.unique && arr.some((x) => _isEqual(x, val))) {
      return arr;
    }
    arr.push(val);
    return arr;
  }
};

if (import.meta.vitest) {
  const { describe, it, assert } = import.meta.vitest;

  it("pushes to existing array", function () {
    const obj = {
      arr: [1],
    };
    pushSet(obj, ["arr"], 2);
    assert.deepStrictEqual(obj, { arr: [1, 2] });
  });

  it("sets array for not existing", function () {
    const obj = {};
    pushSet(obj, ["arr"], 2);
    assert.deepStrictEqual(obj, { arr: [2] });
  });

  it("adds existing element", function () {
    const obj = {
      arr: [1],
    };
    pushSet(obj, ["arr"], 1);
    assert.deepStrictEqual(obj, { arr: [1, 1] });
  });

  it("skips existing element", function () {
    const obj = {
      arr: [1],
    };
    pushSet(obj, ["arr"], 1, { unique: true });
    assert.deepStrictEqual(obj, { arr: [1] });
  });

  describe("deep dot notation", function () {
    it("deep: pushes to existing array", function () {
      const obj = {
        nested: { deep: [{ arr: [1] }] },
      };
      pushSet(obj, ["nested", "deep", 0, "arr"], 2);
      assert.deepStrictEqual(obj, { nested: { deep: [{ arr: [1, 2] }] } });
    });

    it("deep: sets array for not existing", function () {
      const obj = {};
      pushSet(obj, ["nested", "deep", 0, "arr"], 2);
      assert.deepStrictEqual(obj, { nested: { deep: [{ arr: [2] }] } });
    });

    it("deep: adds existing element", function () {
      const obj = {
        nested: { deep: [{ arr: [1] }] },
      };
      pushSet(obj, ["nested", "deep", 0, "arr"], 1);
      assert.deepStrictEqual(obj, { nested: { deep: [{ arr: [1, 1] }] } });
    });

    it("deep: skips existing element", function () {
      const obj = {
        nested: { deep: [{ arr: [1] }] },
      };
      pushSet(obj, ["nested", "deep", 0, "arr"], 1, { unique: true });
      assert.deepStrictEqual(obj, { nested: { deep: [{ arr: [1] }] } });
    });
  });
}