# Testing for type stability regressions

**URL:** <https://discourse.julialang.org/t/testing-for-type-stability-regressions/10629>\
**Category:** Internals & Design\
**Tags:** testing, type-stability\
**Created:** [April 30, 2018, 11:31pm UTC](https://discourse.julialang.org/t/testing-for-type-stability-regressions/10629 "2018-04-30T23:31:57Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![Raf](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/raf/32/3383_2.png) [@Raf](https://discourse.julialang.org/u/Raf)\
**Post date:** [May 1, 2018, 2:28am UTC](https://discourse.julialang.org/t/testing-for-type-stability-regressions/10629/3 "2018-05-01T02:28:57Z")

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I’ve been using that, but it seems that it doesn’t really check that all the code generated is type stable, just that the result is?

@inferred might pass just fine but @code\_warntype can still show a whole lot of Union types. Maybe I need to be more specific in how I’m using it. It just seemed like there could be a general test of stability for a whole block of code, not just the result.

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