Make tests for issue 936 more robust
Make tests for issue 936 more robust

It is good we check that say

    abs(x).expand(trig=True)

does not raise,  but it would be better to actually also check its result -- So
I've just added appropriate asserts like

    assert abs(x).expand(trig=True)  == abs(x)


Signed-off-by: Kirill Smelkov <b0eeaac46e675e9f95bf68c0df1041cf581c26f4@landau.phys.spbu.ru>

dqnykamp/sympy,lindsayad/sympy,wanglongqi/sympy,iamutkarshtiwari/sympy,postvakje/sympy,hrashk/sympy,Designist/sympy,VaibhavAgarwalVA/sympy,Davidjohnwilson/sympy,MechCoder/sympy,hrashk/sympy,cccfran/sympy,Sumith1896/sympy,skirpichev/omg,kumarkrishna/sympy,ahhda/sympy,MechCoder/sympy,vipulroxx/sympy,maniteja123/sympy,debugger22/sympy,pandeyadarsh/sympy,Vishluck/sympy,chaffra/sympy,shipci/sympy,Curious72/sympy,ChristinaZografou/sympy,amitjamadagni/sympy,pbrady/sympy,farhaanbukhsh/sympy,asm666/sympy,toolforger/sympy,kaushik94/sympy,Shaswat27/sympy,MechCoder/sympy,minrk/sympy,tovrstra/sympy,fperez/sympy,Sumith1896/sympy,madan96/sympy,Titan-C/sympy,kmacinnis/sympy,amitjamadagni/sympy,ga7g08/sympy,liangjiaxing/sympy,beni55/sympy,dqnykamp/sympy,sahilshekhawat/sympy,rahuldan/sympy,VaibhavAgarwalVA/sympy,aktech/sympy,mafiya69/sympy,kmacinnis/sympy,shipci/sympy,pernici/sympy,emon10005/sympy,mcdaniel67/sympy,debugger22/sympy,Vishluck/sympy,hargup/sympy,AkademieOlympia/sympy,postvakje/sympy,kaichogami/sympy,souravsingh/sympy,atreyv/sympy,atsao72/sympy,ahhda/sympy,MridulS/sympy,kevalds51/sympy,hazelnusse/sympy-old,AkademieOlympia/sympy,bukzor/sympy,skidzo/sympy,beni55/sympy,Titan-C/sympy,vipulroxx/sympy,skidzo/sympy,yukoba/sympy,kumarkrishna/sympy,jamesblunt/sympy,moble/sympy,abloomston/sympy,mcdaniel67/sympy,cswiercz/sympy,pbrady/sympy,Davidjohnwilson/sympy,beni55/sympy,Arafatk/sympy,jaimahajan1997/sympy,emon10005/sympy,sunny94/temp,kevalds51/sympy,yukoba/sympy,grevutiu-gabriel/sympy,chaffra/sympy,atsao72/sympy,aktech/sympy,kaushik94/sympy,yashsharan/sympy,garvitr/sympy,jbaayen/sympy,postvakje/sympy,grevutiu-gabriel/sympy,liangjiaxing/sympy,hazelnusse/sympy-old,Arafatk/sympy,Gadal/sympy,drufat/sympy,abhiii5459/sympy,liangjiaxing/sympy,abhiii5459/sympy,souravsingh/sympy,pandeyadarsh/sympy,oliverlee/sympy,oliverlee/sympy,sahilshekhawat/sympy,yashsharan/sympy,Gadal/sympy,madan96/sympy,ga7g08/sympy,mafiya69/sympy,cswiercz/sympy,maniteja123/sympy,hrashk/sympy,shikil/sympy,jerli/sympy,madan96/sympy,farhaanbukhsh/sympy,chaffra/sympy,kmacinnis/sympy,saurabhjn76/sympy,sunny94/temp,AunShiLord/sympy,bukzor/sympy,kumarkrishna/sympy,Curious72/sympy,Mitchkoens/sympy,yashsharan/sympy,vipulroxx/sympy,yukoba/sympy,jbbskinny/sympy,jbbskinny/sympy,Designist/sympy,drufat/sympy,abhiii5459/sympy,Vishluck/sympy,atreyv/sympy,Shaswat27/sympy,Gadal/sympy,sampadsaha5/sympy,lindsayad/sympy,Shaswat27/sympy,VaibhavAgarwalVA/sympy,emon10005/sympy,rahuldan/sympy,lidavidm/sympy,diofant/diofant,jerli/sympy,jbbskinny/sympy,Titan-C/sympy,mcdaniel67/sympy,farhaanbukhsh/sympy,rahuldan/sympy,AunShiLord/sympy,asm666/sympy,cccfran/sympy,garvitr/sympy,shikil/sympy,sunny94/temp,aktech/sympy,Curious72/sympy,moble/sympy,drufat/sympy,Arafatk/sympy,maniteja123/sympy,hargup/sympy,iamutkarshtiwari/sympy,lidavidm/sympy,garvitr/sympy,AunShiLord/sympy,souravsingh/sympy,Designist/sympy,wyom/sympy,Davidjohnwilson/sympy,sampadsaha5/sympy,abloomston/sympy,sampadsaha5/sympy,jerli/sympy,pandeyadarsh/sympy,debugger22/sympy,meghana1995/sympy,ChristinaZografou/sympy,ga7g08/sympy,hargup/sympy,dqnykamp/sympy,sahilshekhawat/sympy,ryanGT/sympy,saurabhjn76/sympy,wanglongqi/sympy,kaushik94/sympy,flacjacket/sympy,atreyv/sympy,sahmed95/sympy,jaimahajan1997/sympy,moble/sympy,wanglongqi/sympy,meghana1995/sympy,ChristinaZografou/sympy,shipci/sympy,MridulS/sympy,AkademieOlympia/sympy,sahmed95/sympy,jaimahajan1997/sympy,iamutkarshtiwari/sympy,oliverlee/sympy,ahhda/sympy,lidavidm/sympy,wyom/sympy,atsao72/sympy,KevinGoodsell/sympy,jamesblunt/sympy,asm666/sympy,mafiya69/sympy,MridulS/sympy,wyom/sympy,meghana1995/sympy,saurabhjn76/sympy,toolforger/sympy,Mitchkoens/sympy,pbrady/sympy,shikil/sympy,kaichogami/sympy,sahmed95/sympy,cccfran/sympy,Mitchkoens/sympy,abloomston/sympy,minrk/sympy,kevalds51/sympy,jamesblunt/sympy,toolforger/sympy,grevutiu-gabriel/sympy,skidzo/sympy,lindsayad/sympy,bukzor/sympy,kaichogami/sympy,cswiercz/sympy,mattpap/sympy-polys,srjoglekar246/sympy,Sumith1896/sympy