{"action":"created","issue":{"url":"https://api.github.com/repos/facebook/flow/issues/813","labels_url":"https://api.github.com/repos/facebook/flow/issues/813/labels{/name}","comments_url":"https://api.github.com/repos/facebook/flow/issues/813/comments","events_url":"https://api.github.com/repos/facebook/flow/issues/813/events","html_url":"https://github.com/facebook/flow/issues/813","id":107078939,"number":813,"title":"Property assignment on object with null prototype fails","user":{"login":"Gozala","id":21236,"avatar_url":"https://avatars.githubusercontent.com/u/21236?v=3","gravatar_id":"","url":"https://api.github.com/users/Gozala","html_url":"https://github.com/Gozala","followers_url":"https://api.github.com/users/Gozala/followers","following_url":"https://api.github.com/users/Gozala/following{/other_user}","gists_url":"https://api.github.com/users/Gozala/gists{/gist_id}","starred_url":"https://api.github.com/users/Gozala/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Gozala/subscriptions","organizations_url":"https://api.github.com/users/Gozala/orgs","repos_url":"https://api.github.com/users/Gozala/repos","events_url":"https://api.github.com/users/Gozala/events{/privacy}","received_events_url":"https://api.github.com/users/Gozala/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/facebook/flow/labels/bug","name":"bug","color":"fc2929"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-09-17T21:37:00Z","updated_at":"2016-01-27T07:19:24Z","closed_at":null,"body":"Flow currently does not typecheks following code snippet:\r\n\r\n```js\r\n/* @flow */\r\nexport var html = Object.create(null);\r\n\r\n[\"a\",\"abbr\",\"address\"].forEach(tagName => {\r\n  html[tagName] = (properties, children) =>\r\n    ({tagName, properties, children})\r\n});\r\n```\r\n\r\nproducing following error:\r\n\r\n```js\r\n/Users/gozala/Projects/reflex/src/core.js:4:1,7:2: call of method forEach\r\nError:\r\n/Users/gozala/Projects/reflex/src/core.js:4:2,4: property `a`\r\nProperty not found in possibly null value\r\n/Users/gozala/Projects/reflex/src/core.js:2:33,36: null\r\n\r\n/Users/gozala/Projects/reflex/src/core.js:4:1,7:2: call of method forEach\r\nError:\r\n/Users/gozala/Projects/reflex/src/core.js:4:6,11: property `abbr`\r\nProperty not found in possibly null value\r\n/Users/gozala/Projects/reflex/src/core.js:2:33,36: null\r\n\r\n/Users/gozala/Projects/reflex/src/core.js:4:1,7:2: call of method forEach\r\nError:\r\n/Users/gozala/Projects/reflex/src/core.js:4:13,21: property `address`\r\nProperty not found in possibly null value\r\n/Users/gozala/Projects/reflex/src/core.js:2:33,36: null\r\n```"},"comment":{"url":"https://api.github.com/repos/facebook/flow/issues/comments/175458604","html_url":"https://github.com/facebook/flow/issues/813#issuecomment-175458604","issue_url":"https://api.github.com/repos/facebook/flow/issues/813","id":175458604,"user":{"login":"samwgoldman","id":254842,"avatar_url":"https://avatars.githubusercontent.com/u/254842?v=3","gravatar_id":"","url":"https://api.github.com/users/samwgoldman","html_url":"https://github.com/samwgoldman","followers_url":"https://api.github.com/users/samwgoldman/followers","following_url":"https://api.github.com/users/samwgoldman/following{/other_user}","gists_url":"https://api.github.com/users/samwgoldman/gists{/gist_id}","starred_url":"https://api.github.com/users/samwgoldman/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/samwgoldman/subscriptions","organizations_url":"https://api.github.com/users/samwgoldman/orgs","repos_url":"https://api.github.com/users/samwgoldman/repos","events_url":"https://api.github.com/users/samwgoldman/events{/privacy}","received_events_url":"https://api.github.com/users/samwgoldman/received_events","type":"User","site_admin":false},"created_at":"2016-01-27T07:19:24Z","updated_at":"2016-01-27T07:19:24Z","body":"Simpler repro:\r\n\r\n```javascript\r\n/* @flow */\r\nlet o = Object.create(null);\r\no.p = null;\r\n```\r\n\r\n```\r\ntest.js:4\r\n  4: o.p = null;\r\n       ^ property `p`. Property not found in possibly null value\r\n  3: let o = Object.create(null);\r\n                           ^^^^ null\r\n```"}}