{"action":"opened","issue":{"url":"https://api.github.com/repos/rpominov/kefir/issues/123","labels_url":"https://api.github.com/repos/rpominov/kefir/issues/123/labels{/name}","comments_url":"https://api.github.com/repos/rpominov/kefir/issues/123/comments","events_url":"https://api.github.com/repos/rpominov/kefir/issues/123/events","html_url":"https://github.com/rpominov/kefir/issues/123","id":94921657,"number":123,"title":"Mystified by concat behaviour, thought was a bug, now feature request","user":{"login":"cefn","id":159819,"avatar_url":"https://avatars.githubusercontent.com/u/159819?v=3","gravatar_id":"","url":"https://api.github.com/users/cefn","html_url":"https://github.com/cefn","followers_url":"https://api.github.com/users/cefn/followers","following_url":"https://api.github.com/users/cefn/following{/other_user}","gists_url":"https://api.github.com/users/cefn/gists{/gist_id}","starred_url":"https://api.github.com/users/cefn/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/cefn/subscriptions","organizations_url":"https://api.github.com/users/cefn/orgs","repos_url":"https://api.github.com/users/cefn/repos","events_url":"https://api.github.com/users/cefn/events{/privacy}","received_events_url":"https://api.github.com/users/cefn/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-07-14T11:11:01Z","updated_at":"2015-07-14T11:11:01Z","closed_at":null,"body":"I had a test case where I was mystified why Kefir wasn't sending any events.\r\n\r\nhttps://gist.github.com/cefn/324dc4157e431f37c982\r\n\r\nIt turns out to be a feature of the array traversal of concat which makes it very prone to silent failure if you invoke like...\r\n\r\n    Kefir.concat(obs1,obs2);\r\n\r\n...instead of \r\n\r\n    Kefir.concat([obs1,obs2]);\r\n\r\nIn any case this silent failure is a very tricky situation which would ideally be ironed out of the library It could be fixed by either...\r\n* Failing harder when a non-array argument is passed (people using other stream libraries which support multiple ways of invoking would be very prone to this)\r\n* Actively handle the case where a non-array argument is passed, and treat all the arguments as observables."}}