Add an all.equal implementation for Bitset. (#192)

Calling `all.equal` (or equivalently `expect_equal`) on bitsets has
never worked correctly. For some reason, externalptr always compare as
equal, thus, under the R6 implementation, any bitset with the same max
size was treated as equal.

With the recent switch to a named list and bitsets would sometimes be
considered different, even where their contents were the same. More
precisely, the arguments of `Bitset$new` now happen to be captured by
all of the methods' environments and were being included in the
comparison. A bitset created with `new(size=N)` would always be
different compared to a bitset created with `new(from=ptr)`.

malariasimulation has some tests that use `mockery::expect_args` to
compare bitset arguments, and these tests are now broken by the new
individual version.

NAMESPACE

@@ -1,5 +1,6 @@
 # Generated by roxygen2: do not edit by hand
 
+S3method(all.equal,Bitset)
 export(Bitset)
 export(CategoricalVariable)
 export(DoubleVariable)

R/bitset.R

@@ -227,6 +227,21 @@ Bitset <- list(
   }
 )
 
+#' @export
+#' @method all.equal Bitset
+all.equal.Bitset <- function(target, current, ...) {
+  if (!inherits(current, "Bitset")) {
+    return("'current' is not a Bitset")
+  }
+
+  if (target$max_size != current$max_size) {
+    return(paste0(
+      "Bitset capacity differs (", target$max_size, " vs ",
+      current$max_size,  ")"))
+  }
+  all.equal(target$to_vector(), current$to_vector(), ...)
+}
+
 #' @title Filter a bitset
 #' @description This non-modifying function returns a new \code{\link{Bitset}}
 #' object of the same maximum size as the original but which only contains

tests/testthat/test-bitset.R

@@ -358,3 +358,44 @@ test_that("bitset sampling has correctly distributed size", {
     expect_gt(p, threshold)
   }
 })
+
+test_that("bitset equality works", {
+  a <- Bitset$new(10)
+  b <- Bitset$new(10)
+  c <- Bitset$new(10)
+  d <- Bitset$new(10)
+  e <- Bitset$new(10)
+  f <- Bitset$new(10)
+
+  c$insert(c(1, 2, 3))
+  d$insert(c(1, 2, 3))
+  e$insert(c(4, 5, 6))
+  f$insert(c(4, 7))
+
+  expect_equal(a, b)
+  expect_equal(c, d)
+
+  expect_false(isTRUE(all.equal(a, c)))
+  expect_false(isTRUE(all.equal(a, e)))
+  expect_false(isTRUE(all.equal(a, f)))
+  expect_false(isTRUE(all.equal(c, e)))
+  expect_false(isTRUE(all.equal(c, f)))
+  expect_false(isTRUE(all.equal(e, f)))
+
+  expect_equal(a, a$copy())
+  expect_equal(c, c$copy())
+  expect_equal(e, e$copy())
+  expect_equal(f, f$copy())
+})
+
+test_that("bitsets with different capacities are not equal", {
+  a <- Bitset$new(10)
+  b <- Bitset$new(11)
+  expect_match(all.equal(a, b), "Bitset capacity differs")
+})
+
+test_that("bitset is not equal to other types", {
+  a <- Bitset$new(10)
+  a$insert(c(1,4,5))
+  expect_equal(all.equal(a, c(1,4,5)), "'current' is not a Bitset")
+})