better arg defaults

Author: boshek

R/historical-webservice.R

@@ -6,12 +6,10 @@
 #' you need lots of data, consider using HYDAT and the `hy_` family of functions
 #'
 #' @param station_number Water Survey of Canada station number.
-#' @param start_date Accepts YYYY-MM-DD.
-#' If only start date is supplied (i.e. YYYY-MM-DD) values are returned from the start of that day.
-#' Defaults to 365 days before current date. 
-#' @param end_date Accepts either YYYY-MM-DD.
-#' If only a date is supplied (i.e. YYYY-MM-DD) values are returned from the end of that day.
-#' Defaults to current date.
+#' @param start_date Accepts YYYY-MM-DD. You need to provide a start date. 
+#' The default value is NULL
+#' @param end_date Accepts either YYYY-MM-DD. You need to provide an end date. 
+#' The default value is NULL
 #'
 #'
 #' @format A tibble with 6 variables:
@@ -26,20 +24,26 @@
 #' @seealso hy_daily_flows
 #' @examples
 #' \dontrun{
-#'
-#' flow_data <- ws_daily_flows(
-#'   station_number = c("08NL071", "08NM174")
+#' try(
+#'    flow_data <- ws_daily_flows(
+#'      station_number = c("08NL071", "08NM174"),
+#'      start_date = Sys.Date() - 365,
+#'      end_date = Sys.Date()
+#'    )
 #' )
-#'
-#' level_data <- ws_daily_level(
-#'   station_number = c("08NL071", "08NM174")
+#' try(
+#'    level_data <- ws_daily_level(
+#'      station_number = c("08NL071", "08NM174"),
+#'      start_date = Sys.Date() - 365,
+#'      end_date = Sys.Date()
+#'      )
 #' )
-#' }
+#'}
 #' @export
 ws_daily_flows <- function(
     station_number,
-    start_date = Sys.Date() - 365,
-    end_date = Sys.Date()) {
+    start_date = NULL,
+    end_date = NULL) {
 
   get_historical_data(
     station_number = station_number,
@@ -53,8 +57,8 @@ ws_daily_flows <- function(
 #' @export
 ws_daily_levels <- function(
     station_number,
-    start_date = Sys.Date() - 365,
-    end_date = Sys.Date()) {
+    start_date = NULL,
+    end_date = NULL) {
 
   get_historical_data(
     station_number = station_number,
@@ -72,6 +76,14 @@ get_historical_data <- function(
     end_date) {
   parameters <- match.arg(parameters, choices = c("level", "flow"))
 
+  if (is.null(start_date)) {
+    stop("please provide a valid date for the start_date argument", call. = FALSE)
+  }
+
+  if (is.null(end_date)) {
+    stop("please provide a valid date for the end_date argument", call. = FALSE)
+  }
+
   ## Build link for GET
   baseurl <- "https://wateroffice.ec.gc.ca/services/daily_data/csv/inline?"
 

man/ws_daily_flows.Rd

@@ -1,7 +1,11 @@
 test_that("ws_daily_flows returns the correct data header", {
   skip_on_cran()
 
-  ws_test <- ws_daily_flows(station_number = "08MF005")
+  ws_test <- ws_daily_flows(
+    station_number = "08MF005",
+    start_date = Sys.Date() - 365,
+    end_date = Sys.Date()
+  )
 
   expect_identical(
     colnames(ws_test),
@@ -19,13 +23,18 @@ test_that("ws_daily_flows is empty with a nearish date", {
   expect_error(ws_daily_flows(
     station_number = "08MF005",
     start_date = Sys.Date() - 2
+    end_date = Sys.Date()
   ), "No data exists for this station query during the period chosen")
 })
 
 test_that("ws_daily_levels returns the correct data header", {
   skip_on_cran()
 
-  ws_test <- ws_daily_levels(station_number = "08MF005")
+  ws_test <- ws_daily_levels(
+    station_number = "08MF005",
+    start_date = Sys.Date(),
+    end_date = Sys.Date() - 365
+  )
 
   expect_identical(
     colnames(ws_test),
@@ -45,3 +54,25 @@ test_that("ws_daily_levels is empty with a nearish date", {
     start_date = Sys.Date() - 2
   ), "No data exists for this station query during the period chosen")
 })
+
+test_that("get_historical_data error informatively with no dates given",{
+  expect_error(
+    get_historical_data(
+      station_number = "08MF005"
+    ),
+    "please provide a valid date for the start_date argument"
+  )
+
+  expect_error(
+    get_historical_data(
+      station_number = "08MF005",
+      start_date = Sys.Date(),
+      end_date = NULL
+    ),
+    "please provide a valid date for the start_date argument"
+  )
+})
+
+test_that("function can take a string for date", {
+
+})