[Fix #887] Error on invalid numeric input to month()

NEWS.md

@@ -4,7 +4,7 @@ Version 1.7.8.9000 (dev)
 ### BUG FIXES
 
 * [#886](https://github.com/tidyverse/lubridate/issues/886) Fix `with_tz()` for POSIXlt objects
-
+* [#887](https://github.com/tidyverse/lubridate/issues/887) Error on invalid numeric input to `month()`
 Version 1.7.8
 =============
 

R/accessors-day.r

@@ -76,7 +76,8 @@ wday.numeric <- function(x, label = FALSE, abbr = TRUE,
 
   start <- as.integer(week_start)
 
-  if (start > 7 || start < 1) stop("Invalid 'week_start' argument; must be between 1 and 7")
+  if (start > 7 || start < 1)
+    stop("Invalid 'week_start' argument; must be between 1 and 7")
 
   if (start != 7) {
     x <- 1 + (x + (6 - start)) %% 7

R/accessors-month.r

@@ -38,7 +38,12 @@ month.default <- function(x, label = FALSE, abbr = TRUE, locale = Sys.getlocale(
 
 #' @export
 month.numeric <- function(x, label = FALSE, abbr = TRUE, locale = Sys.getlocale("LC_TIME")) {
-  if (!label) return(x)
+  if (!all(x[!is.na(x)] %in% 1:12))
+    stop("Values are not in 1:12")
+
+  if (!label) {
+    return(x)
+  }
 
   names <- .get_locale_regs(locale)$month_names
   labels <- if (abbr) names$abr else names$full

tests/testthat/test-accessors.R

@@ -214,6 +214,16 @@ test_that("months accessor extracts correct month", {
 
 })
 
+test_that("month() on numeric input doesn't accept invalid values", {
+  expect_error(month(0:13))
+  expect_error(month(c(0:13, NA)))
+  expect_error(month(0))
+  expect_error(month(0), label = TRUE)
+  expect_equal(month(1:12), 1:12)
+  expect_equal(month(c(1:12, NA)), c(1:12, NA))
+  expect_equal(month(as.double(1:12)), 1:12)
+})
+
 test_that("quarters accessor extracts correct quarter", {
   posct <- ymd_hms("2010-11-03 13:45:59")
   poslt <- as.POSIXlt(posct)