code: function addToArrayByNode(node, code) {
    // node: the arr expression node
    // code: added as the last element of the array
  
    const multilines = node.loc.start.line !== node.loc.end.line;
    let insertPos = node.start + 1; // insert after '['
  
    if (node.elements.length) {
      const ele = _.last(node.elements);
      insertPos = ele.end;
    }
  
    let replacement;
    if (multilines) {
      const indent = _.repeat(' ', node.loc.end.column - 1);
      replacement = `\n${indent}  ${code}`;
      if (node.elements.length) {
        replacement = `,${replacement}`;
      } else {
        replacement = `${replacement},`;
      }
    } else {
      replacement = code;
      if (node.elements.length > 0) {
        replacement = `, ${code}`;
      }
    }
    return [
      {
        start: insertPos,
        end: insertPos,
        replacement,
      },
    ];
  }
docs: Add an element to an array definition.
  @param {object} node - The ast node of the array definition.
  @param {string} code - The code to append to the array.
  @alias module:refactor.addToArrayByNode
  @