jeremyjung e7caa7afd5 Allow has_one nil association (#48)
* Allow has_one nil association

* add test for when has_one returns nil

* modify has_one extension method, add active record test

* Use try operator to support old rubies
2018-02-07 08:54:53 -08:00
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2018-02-05 22:34:17 -08:00