update tests

tests/testthat/test_voting_methods.R

@@ -10,12 +10,20 @@ w_equal = rep(1, n_voters)
 
 # small data example
 cand2 = paste0("V", seq_len(5))
+# "V3" candidate in all sets, "V1" in half, "V2", "V4" once, "V5" nowhere!
 vot2 = list(
-  # "V3" candidate in all sets, "V1" in half, "V2", "V4" once, "V5" nowhere!
   c("V3", "V1", "V2"),
   c("V3", "V1"),
   c("V3", "V4"),
-  c("V3"))
+  c("V3")
+)
+# edge case: all voters voted the same candidates, "V4" and "V5" are nowhere!
+vot3 = list(
+  c("V3", "V1", "V2"),
+  c("V3", "V1", "V2"),
+  c("V3", "V1", "V2"),
+  c("V3", "V1", "V2")
+)
 w2 = runif(length(vot2))
 w2_equal = rep(1, length(vot2))
 
@@ -51,6 +59,12 @@ test_that("approval voting", {
   expect_equal(av2_equalw$feature[5], "V5")
   expect_equal(av2_equalw$score, c(4, 2, 1, 1, 0))
   expect_equal(av2_equalw$norm_score, c(1, 0.5, 0.25, 0.25, 0))
+
+  # tie breaking
+  av3 = approval_voting(vot3, cand2, w2)
+  expect_contains(av3$feature[1:3], c("V1", "V2", "V3"))
+  expect_true(length(unique(av3$score[1:3])) == 1) # all scores the same
+  expect_contains(av3$feature[4:5], c("V4", "V5"))
 })
 
 test_that("satisfaction approval voting", {
@@ -82,16 +96,22 @@ test_that("satisfaction approval voting", {
 
   sav2_equalw = satisfaction_approval_voting(vot2, cand2, w2_equal)
   expect_equal(sav2_equalw$feature, c("V3", "V1", "V4", "V2", "V5"))
+
+  # tie breaking
+  sav3 = satisfaction_approval_voting(vot3, cand2, w2)
+  expect_contains(sav3$feature[1:3], c("V1", "V2", "V3"))
+  expect_true(length(unique(sav3$score[1:3])) == 1) # all scores the same
+  expect_contains(sav3$feature[4:5], c("V4", "V5"))
 })
 
 test_that("sequential proportional approval voting", {
   # large data
-  size = 2 # just get top 2 ranked features
+  size = 5 # get top 5 ranked features
   sp = seq_proportional_approval_voting(vot, cand, w, size)
   expect_data_table(sp, nrows = size, ncols = 2)
   expect_setequal(colnames(sp), c("feature", "borda_score"))
-  sp1 = seq_proportional_approval_voting(vot, cand, w, committee_size = 1)
-  expect_equal(sp$feature[1], sp1$feature[1]) # house monotonicity
+  sp1 = seq_proportional_approval_voting(vot, cand, w, committee_size = 3)
+  expect_equal(sp$feature[1:3], sp1$feature[1:3]) # house monotonicity
 
   spe = seq_proportional_approval_voting(vot, cand, w_equal, size)
   expect_data_table(spe, nrows = size, ncols = 2)
@@ -110,19 +130,9 @@ test_that("sequential proportional approval voting", {
   expect_setequal(colnames(seq_pav2_equal), c("feature", "borda_score"))
   expect_equal(seq_pav2_equal$borda_score[1], 1)
   expect_equal(seq_pav2_equal$borda_score[length(cand2)], 0)
-})
 
-test_that("reverse sequential proportional approval voting", {
-  # small data
-  rs_pav = revseq_proportional_approval_voting(vot2, cand2, w2)
-  expect_data_table(rs_pav, nrows = length(cand2), ncols = 2)
-  expect_setequal(colnames(rs_pav), c("feature", "borda_score"))
-  expect_equal(rs_pav$borda_score[1], 1)
-  expect_equal(rs_pav$borda_score[length(cand2)], 0)
-
-  rs_pav_equal = seq_proportional_approval_voting(vot2, cand2, w2_equal)
-  expect_data_table(rs_pav_equal, nrows = length(cand2), ncols = 2)
-  expect_setequal(colnames(rs_pav_equal), c("feature", "borda_score"))
-  expect_equal(rs_pav_equal$borda_score[1], 1)
-  expect_equal(rs_pav_equal$borda_score[length(cand2)], 0)
+  # tie breaking
+  seq_pav3 = seq_proportional_approval_voting(vot3, cand2, w2)
+  expect_contains(seq_pav3$feature[1:3], c("V1", "V2", "V3"))
+  expect_contains(seq_pav3$feature[4:5], c("V4", "V5"))
 })