Method update

src/Map.js:357–404

(ownerID, shift, keyHash, key, value, didChangeSize, didAlter)

  }

  update(ownerID, shift, keyHash, key, value, didChangeSize, didAlter) {
    if (keyHash === undefined) {
      keyHash = hash(key);
    }
    const idx = (shift === 0 ? keyHash : keyHash >>> shift) & MASK;
    const removed = value === NOT_SET;
    const nodes = this.nodes;
    const node = nodes[idx];

    if (removed && !node) {
      return this;
    }

    const newNode = updateNode(
      node,
      ownerID,
      shift + SHIFT,
      keyHash,
      key,
      value,
      didChangeSize,
      didAlter
    );
    if (newNode === node) {
      return this;
    }

    let newCount = this.count;
    if (!node) {
      newCount++;
    } else if (!newNode) {
      newCount--;
      if (newCount < MIN_HASH_ARRAY_MAP_SIZE) {
        return packNodes(ownerID, nodes, newCount, idx);
      }
    }

    const isEditable = ownerID && ownerID === this.ownerID;
    const newNodes = setAt(nodes, idx, newNode, isEditable);

    if (isEditable) {
      this.count = newCount;
      this.nodes = newNodes;
      return this;
    }

    return new HashArrayMapNode(ownerID, newCount, newNodes);
  }
}

/**