logo /logo search Search menu 1 sign up or log in log in .user-info /menu 1 menu 2 node package manager Toggle Navigation npm Enterprise features pricing documentation support /menu 2 babel-plugin-transform-builtin-extend This is a Babel 6 plugin to enable extending builtin types like "Error" and "Array" and such, which require special treatment and require static analysis to detect. In your Babel 6 configuration, for example in a .babelrc you might have { "plugins": [ ["babel-plugin-transform-builtin-extend", { globals: ["Error", "Array"] }] ] } which would enable the plugin and configure it to look for any class extending Error or Array globals. On older browsers that do not support reassigning the prototype of an existing object, you will need to enable the approximate mode, which will fall back to the Babel 5 ...