Babel plugin for safe reading and setting of deeply nested objects in js

experiment.js

const exceptions = ["console"];

function getExp(node, all) {
  let str = all;
  let id = "";
  if (node.property.type === "Identifier") {
    str = `.${node.property.name}${str ? str : ""}`;
  } else if (node.property.type === "NumericLiteral") {
    str = `.${node.property.value}${str ? str : ""}`;
  } else if (node.property.type === "StringLiteral") {
    str = `[${node.property.value}]${str ? str : ""}`;
  }
  if (node.object.type === "MemberExpression") {
    const get = getExp(node.object, str);
    str = get.str;
    id = get.id;
  } else if (node.object.type === "Identifier") {
    id = node.object.name;
  } else if (node.object.type === "ThisExpression") {
    id = "this";
  }
  return { str, id };
}

export default function(babel) {
  const { types: t } = babel;

  return {
    name: "ast-transform", // not required
    visitor: {
      AssignmentExpression(path) {
        console.log("path", path);
        if (path.node.left && path.node.left.type === "MemberExpression") {
          const exp = getExp(path.node.left);
          const newNode = t.callExpression(t.identifier("safeSet"), [
            t.identifier(exp.id),
            t.stringLiteral(exp.str.substr(1)),
            path.node.right
          ]);
          path.replaceWith(newNode);
        }
      },
      MemberExpression(path) {
        if (path.parent && path.parent.type === "AssignmentExpression") {
        } else {
          const exp = getExp(path.node);
          const newNode = t.callExpression(t.identifier("safeRead"), [
            t.identifier(exp.id),
            t.stringLiteral(exp.str.substr(1))
          ]);
          if (!exceptions.includes(exp.id)) {
            path.replaceWith(newNode);
          }
        }
      }
    }
  };
}