Add tests

tests/testthat/test-pivot_wider.R

@@ -239,3 +239,118 @@ test_that("correctly labels columns when `names_glue` is used, #579", {
   expect_named(result2, c("v1_b", "v1_a", "v1_c", "v2_b", "v2_a", "v2_c"))
   expect_equal(unname(unlist(result2)), c("b", "a", "c", "b", "a", "c"))
 })
+
+# unused -------------------------------------------------------------------
+
+test_that("`unused_fn` can summarize unused columns (#990)", {
+  df <- tidytable(
+    id = c(1, 1, 2, 2),
+    unused1 = c(1, 2, 4, 3),
+    unused2 = c(1, 2, 4, 3),
+    name = c("a", "b", "a", "b"),
+    value = c(1, 2, 3, 4)
+  )
+
+  # # By name
+  # res <- pivot_wider(df, id_cols = id, unused_fn = list(unused1 = max))
+  # expect_named(res, c("id", "a", "b", "unused1"))
+  # expect_identical(res$unused1, c(2, 4))
+
+  # Globally
+  res <- pivot_wider(df, id_cols = id, unused_fn = list)
+  expect_named(res, c("id", "a", "b", "unused1", "unused2"))
+  expect_identical(res$unused1, list(c(1, 2), c(4, 3)))
+  expect_identical(res$unused2, list(c(1, 2), c(4, 3)))
+
+  # https://stackoverflow.com/a/73554147
+  df <- data.frame(A = c(1, 1, 1, 2 , 2, 2),
+                   B = c(3, 3, 3, 6, 6, 6),
+                   C = c(2, 3, 9, 12, 2, 6),
+                   D = c("a1", "a2", "a3", "a1", "a2", "a3"))
+
+  res <- df %>%
+    pivot_wider(id_cols = A, names_from = D, values_from = C, unused_fn = mean)
+  expect_named(res, c("A", "a1", "a2", "a3", "B"))
+  expect_equal(res$B, c(3, 6))
+
+  # Works with anonymous functions
+  res <- df %>%
+    pivot_wider(id_cols = A, names_from = D, values_from = C, unused_fn = ~ mean(.x))
+  expect_named(res, c("A", "a1", "a2", "a3", "B"))
+  expect_equal(res$B, c(3, 6))
+})
+
+test_that("`unused_fn` works with anonymous functions", {
+  df <- tidytable(
+    id = c(1, 1, 2, 2),
+    unused = c(1, NA, 4, 3),
+    name = c("a", "b", "a", "b"),
+    value = c(1, 2, 3, 4)
+  )
+
+  res <- pivot_wider(df, id_cols = id, unused_fn = ~ mean(.x, na.rm = TRUE))
+  expect_identical(res$unused, c(1, 3.5))
+})
+
+# test_that("`unused_fn` must result in single summary values", {
+#   df <- tidytable(
+#     id = c(1, 1, 2, 2),
+#     unused = c(1, 2, 4, 3),
+#     name = c("a", "b", "a", "b"),
+#     value = c(1, 2, 3, 4)
+#   )
+#
+#   expect_snapshot(
+#     (expect_error(pivot_wider(df, id_cols = id, unused_fn = identity)))
+#   )
+# })
+
+# test_that("`unused_fn` works with expanded key from `id_expand`", {
+#   df <- tidytable(
+#     id = factor(c(1, 1, 2, 2), levels = 1:3),
+#     unused = c(1, 2, 4, 3),
+#     name = c("a", "b", "a", "b"),
+#     value = c(1, 2, 3, 4)
+#   )
+#
+#   res <- pivot_wider(df, id_cols = id, id_expand = TRUE, unused_fn = max)
+#   expect_identical(res$id, factor(1:3))
+#   expect_identical(res$unused, c(2, 4, NA))
+#
+#   res <- pivot_wider(df, id_cols = id, id_expand = TRUE, unused_fn = ~ sum(is.na(.x)))
+#   expect_identical(res$unused, c(0L, 0L, 1L))
+# })
+
+# test_that("can't fill implicit missings in unused column with `values_fill`", {
+#   # (in theory this would need `unused_fill`, but it would only be used when
+#   # `id_expand = TRUE`, which doesn't feel that useful)
+#
+#   df <- tidytable(
+#     id = factor(c(1, 1, 2, 2), levels = 1:3),
+#     unused = c(1, 2, 4, 3),
+#     name = c("a", "b", "a", "b"),
+#     value = c(1, 2, 3, 4)
+#   )
+#
+#   res <- pivot_wider(
+#     data = df,
+#     id_cols = id,
+#     id_expand = TRUE,
+#     unused_fn = list,
+#     values_fill = 0
+#   )
+#
+#   expect_identical(res$a, c(1, 3, 0))
+#   expect_identical(res$b, c(2, 4, 0))
+#   expect_identical(res$unused, list(c(1, 2), c(4, 3), NA_real_))
+#
+#   res <- pivot_wider(
+#     data = df,
+#     id_cols = id,
+#     id_expand = TRUE,
+#     unused_fn = list,
+#     values_fill = list(unused = 0)
+#   )
+#
+#   expect_identical(res$unused, list(c(1, 2), c(4, 3), NA_real_))
+# })