support tidyr::drop_na()

resolve #173

NEWS.md

@@ -12,6 +12,7 @@ This release marks the migration of tsibble's S3 vector classes, such as `yearqu
 * Added `keyed_lag()`, `keyed_lead()`, and `keyed_difference()` that can be called in `mutate(<tbl_ts>)` to respect tsibble's key and gaps. This improves efficiency in computing time and memory size.
 * The `.full` argument in `*_gaps` support two more options, `start()` and `end()`, for padding to the same starting or ending time. (#147)
 * `select()` a tsibble now keeps both index and key by default. (#155)
+* Added `tidyr::drop_na()` support for tsibble. (#173)
 
 ## Bug fixes
 

R/error.R

@@ -35,9 +35,9 @@ not_tsibble <- function(x) {
 pkg_not_available <- function(pkg, min_version = NULL) {
   pkg_lgl <- requireNamespace(pkg, quietly = TRUE)
   if (!pkg_lgl) {
-    if (is_null(min_version)) {
-      abort(sprintf("Package `%s` required.\nPlease install and try again.", pkg))
-    }
+    abort(sprintf("Package `%s` required.\nPlease install and try again.", pkg))
+  } else if (pkg_lgl && is_null(min_version)) {
+    return()
   } else if (utils::packageVersion(pkg) < min_version) {
     abort(sprintf(
       "Package `%s` (>= v%s) required.\nPlease install and try again.", 

R/tidyr-verbs.R

@@ -11,7 +11,6 @@
 #' )
 #' (stocksm <- stocks %>% gather(stock, price, -time))
 #' stocksm %>% spread(stock, price)
-
 gather.tbl_ts <- function(data, key = "key", value = "value", ...,
                           na.rm = FALSE, convert = FALSE, factor_key = FALSE) {
   key <- as_string(enexpr(key))
@@ -166,3 +165,10 @@ fill.tbl_ts <- function(data, ..., .direction = c("down", "up")) {
 }
 
 fill.grouped_ts <- fill.tbl_ts
+
+drop_na.tbl_ts <- function(data, ...) {
+  res <- NextMethod()
+  update_meta2(res, data, ordered = is_ordered(data), interval = interval(data))
+}
+
+drop_na.grouped_ts <- drop_na.tbl_ts

R/zzz.R

@@ -10,6 +10,8 @@
   s3_register("tidyr::spread", "tbl_ts")
   s3_register("tidyr::fill", "grouped_ts")
   s3_register("tidyr::fill", "tbl_ts")
+  s3_register("tidyr::drop_na", "tbl_ts")
+  s3_register("tidyr::drop_na", "grouped_ts")
   s3_register("tidyr::nest", "tbl_ts")
   s3_register("tidyr::nest", "grouped_ts")
   s3_register("tidyr::unnest", "tbl_ts")

tests/testthat/test-tidyr.R

@@ -121,4 +121,27 @@ test_that("fill()", {
       as_tibble() %>%
       fill(kilo, .direction = "down")
   )
+  expect_is(fill(harvest_fill, kilo), "tbl_ts")
+  expect_is(fill(group_by_key(harvest_fill), kilo), "grouped_ts")
+})
+
+test_that("drop_na() #173", {
+  expect_equal(
+    harvest_fill %>%
+      group_by_key() %>%
+      drop_na(),
+    harvest_fill %>%
+      as_tibble() %>%
+      group_by(fruit) %>%
+      drop_na()
+  )
+  expect_equal(
+    harvest_fill %>%
+      drop_na(),
+    harvest_fill %>%
+      as_tibble() %>%
+      drop_na()
+  )
+  expect_is(drop_na(harvest_fill), "tbl_ts")
+  expect_is(drop_na(group_by_key(harvest_fill)), "grouped_ts")
 })