library(buildmer) library(testthat) test_that('add.terms',{ form <- Reaction ~ Days + (1|Subject) expect_equal(add.terms(form,'Days|Subject') ,Reaction ~ 1 + Days + (1 + Days | Subject)) expect_equal(add.terms(form,'(0+Days|Subject)') ,Reaction ~ 1 + Days + (1 | Subject) + (0 + Days | Subject)) expect_equal(add.terms(form,c('many','more|terms','to|terms','(be|added)','to|test')),Reaction ~ 1 + Days + many + (1 | Subject) + (0 + more + to | terms) + (be | added) + (0 + to | test)) })