[Fix #597] as_datetime understands ymd strings

NEWS.md

@@ -1,3 +1,10 @@
+Version 1.7.0.9000
+==================
+
+## BUG FIXES
+
+* [#597](https://github.com/tidyverse/lubridate/issues/597) Fix incorrect parsing of `ymd` strings by `as_datetime`.
+
 Version 1.7.0
 =============
 

R/coercion.r

@@ -673,7 +673,7 @@ setMethod("as_datetime", "numeric",
 #' @export
 setMethod("as_datetime", "character",
           function(x, tz = "UTC") {
-            parse_date_time(x, orders = c("ymdTz", "ymdT"), tz = tz)
+            parse_date_time(x, orders = c("ymdTz", "ymdT", "ymd"), tz = tz, train = FALSE)
           })
 
 #' @rdname as_date

tests/testthat/test-POSIXt.R

@@ -56,3 +56,28 @@ test_that("addition of large seconds doesn't overflow", {
                          "2038-01-19 03:14:09", "2038-01-19 03:14:10"))
   expect_equal(from_period, from_char)
 })
+
+test_that("as_datetime works correctly", {
+
+  x <- c("17-01-20", "2017-01-20 01:02:03", "2017-03-22T15:48:00.000Z",
+         "2017-01-20", "2017-01-20 01:02:03", "2017-03-22T15:48:00.000Z")
+
+  y <- c("2017-01-20 00:00:00 UTC", "2017-01-20 01:02:03 UTC",
+         "2017-03-22 15:48:00 UTC", "2017-01-20 00:00:00 UTC",
+         "2017-01-20 01:02:03 UTC", "2017-03-22 15:48:00 UTC")
+
+  zns <- c(3, 6)
+  putc <- ymd_hms(y)
+  pus <- ymd_hms(y[-zns], tz = "America/Chicago")
+  expect_equal(as_datetime(x), putc)
+  expect_equal(as_datetime(x[-zns], tz = "America/Chicago"), pus)
+
+  for (i in seq_along(x)) {
+    expect_equal(as_datetime(x[[i]]), putc[[i]])
+  }
+
+  for (i in seq_along(pus)) {
+    expect_equal(as_datetime(x[-zns][[i]], tz = "America/Chicago"), pus[[i]])
+  }
+
+})