tests/testit/test-cache.R

In yihui/knitr: A General-Purpose Package for Dynamic Report Generation in R

library(testit)

assert('find_globals() identifies global variables', {
  # nothing from outside environment
  (find_globals('x=1') %==% character(0))
  # qwer must be created outside somewhere
  (find_globals('a=1; b=a; d=qwer') %==% 'qwer')
  (find_globals('a=function(){f=2;g}') %==% 'g')
  # y was assigned locally in z, but there is another y outside from nowhere
  (find_globals('z=function(){y=1};y') %==% 'y')
  # more complicated cases: operators, subscripts, ...
  (find_globals(c('a=1%*%1%o%2 %in% d', 'b=d%%10+3%/%2-z[1:3]')) %==% c('d', 'z'))
})

assert('find_symbols() identifies all symbols', {
  (find_symbols('x = x + 1; rnorm(1, std = z)') %==% c('x', 'rnorm', 'z'))
})

knit_lazy = function(lazy = TRUE) {
  in_dir(tempdir(), {
    txt = c(sprintf('```{r test, cache=TRUE, cache.lazy=%s}', lazy),
            'x1 = Sys.time()', '```')
    knit(text = txt, quiet = TRUE)
    x2 = x1
    Sys.sleep(0.1)
    knit(text = txt, quiet = TRUE)
    x1 == x2  # x1 should not be updated
  })
}
assert('cache.lazy = TRUE/FALSE works', {
  (knit_lazy(TRUE))
  (knit_lazy(FALSE))
})

knit_code$set(a = 1, b = 2, c = 3)
assert('dep_prev() sets dependencies on previous chunks', {
  # dependency is empty now
  (dep_list$get() %==% list())
  # b/c depend on a, c depends on b
  dep_prev()
  (dep_list$get() %==% list(a = c('b', 'c'), b = 'c'))
})
dep_list$restore()
knit_code$restore()