{"action":"created","issue":{"url":"https://api.github.com/repos/babel/babel/issues/2687","labels_url":"https://api.github.com/repos/babel/babel/issues/2687/labels{/name}","comments_url":"https://api.github.com/repos/babel/babel/issues/2687/comments","events_url":"https://api.github.com/repos/babel/babel/issues/2687/events","html_url":"https://github.com/babel/babel/issues/2687","id":114304760,"number":2687,"title":"When load duplicate plugin babel-preset-es2015, sometimes will throw a error","user":{"login":"zbinlin","id":880513,"avatar_url":"https://avatars.githubusercontent.com/u/880513?v=3","gravatar_id":"","url":"https://api.github.com/users/zbinlin","html_url":"https://github.com/zbinlin","followers_url":"https://api.github.com/users/zbinlin/followers","following_url":"https://api.github.com/users/zbinlin/following{/other_user}","gists_url":"https://api.github.com/users/zbinlin/gists{/gist_id}","starred_url":"https://api.github.com/users/zbinlin/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/zbinlin/subscriptions","organizations_url":"https://api.github.com/users/zbinlin/orgs","repos_url":"https://api.github.com/users/zbinlin/repos","events_url":"https://api.github.com/users/zbinlin/events{/privacy}","received_events_url":"https://api.github.com/users/zbinlin/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/babel/babel/labels/pending%20triage","name":"pending triage","color":"bfe5bf"}],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-10-30T16:26:42Z","updated_at":"2015-11-12T07:33:53Z","closed_at":"2015-11-12T07:33:53Z","body":"babel-core: **v6.0.12**\r\nbabel-preset-es2015: **v6.0.12**\r\n\r\n**Code:**\r\n```js\r\nconst babel = require(\"babel-core\");\r\n\r\nbabel.transform(\"export default class App extends Array {};\", {\r\n    presets: [\"es2015\", \"es2015\"]\r\n});\r\n```\r\n\r\n**Expect:**\r\n no errors\r\n\r\n**Actually:**\r\n throw a error\r\n\r\n>SyntaxError: unknown: 'this' is not allowed before super() (This is an error on an internal node. Probably an internal error)\r\n\r\nOther scene is when write in a .babelrc, and as a options pass to transform function.\r\n\r\nCan automatic remove the duplicate plugins in buildPlugins function? \r\nOr has a scene that use multiple same plugins?"},"comment":{"url":"https://api.github.com/repos/babel/babel/issues/comments/156025096","html_url":"https://github.com/babel/babel/issues/2687#issuecomment-156025096","issue_url":"https://api.github.com/repos/babel/babel/issues/2687","id":156025096,"user":{"login":"thejameskyle","id":952783,"avatar_url":"https://avatars.githubusercontent.com/u/952783?v=3","gravatar_id":"","url":"https://api.github.com/users/thejameskyle","html_url":"https://github.com/thejameskyle","followers_url":"https://api.github.com/users/thejameskyle/followers","following_url":"https://api.github.com/users/thejameskyle/following{/other_user}","gists_url":"https://api.github.com/users/thejameskyle/gists{/gist_id}","starred_url":"https://api.github.com/users/thejameskyle/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/thejameskyle/subscriptions","organizations_url":"https://api.github.com/users/thejameskyle/orgs","repos_url":"https://api.github.com/users/thejameskyle/repos","events_url":"https://api.github.com/users/thejameskyle/events{/privacy}","received_events_url":"https://api.github.com/users/thejameskyle/received_events","type":"User","site_admin":false},"created_at":"2015-11-12T07:33:53Z","updated_at":"2015-11-12T07:33:53Z","body":"The error that was being reported here was actually a separate issue. Babel does not throw any errors when specifying a plugin more than once."}}