From b53b2d067424d62d9c0a8ce1ca1c27e4792ae5b0 Mon Sep 17 00:00:00 2001
From: RodDalBen <dalbenwork@gmail.com>
Date: Thu, 15 Aug 2024 14:47:20 -0600
Subject: [PATCH 1/4] check type for date_breaks and date_minor_breaks #5880

---
 R/scale-date.R | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/R/scale-date.R b/R/scale-date.R
index 36f8b37d83..5f8608d6f3 100644
--- a/R/scale-date.R
+++ b/R/scale-date.R
@@ -303,9 +303,11 @@ datetime_scale <- function(aesthetics, transform, trans = deprecated(),
   if (is.character(minor_breaks)) minor_breaks <- breaks_width(minor_breaks)
 
   if (!is.waive(date_breaks)) {
+    check_string(date_breaks)
     breaks <- breaks_width(date_breaks)
   }
   if (!is.waive(date_minor_breaks)) {
+    check_string(date_minor_breaks)
     minor_breaks <- breaks_width(date_minor_breaks)
   }
   if (!is.waive(date_labels)) {

From fd5a8315c75993ee369e91a1e5432ff329c324b1 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Tue, 10 Sep 2024 10:03:43 +0200
Subject: [PATCH 2/4] `date_labels` should be string too

---
 R/scale-date.R | 1 +
 1 file changed, 1 insertion(+)

diff --git a/R/scale-date.R b/R/scale-date.R
index 5f8608d6f3..0decaa4174 100644
--- a/R/scale-date.R
+++ b/R/scale-date.R
@@ -311,6 +311,7 @@ datetime_scale <- function(aesthetics, transform, trans = deprecated(),
     minor_breaks <- breaks_width(date_minor_breaks)
   }
   if (!is.waive(date_labels)) {
+    check_string(date_labels)
     labels <- function(self, x) {
       tz <- self$timezone %||% "UTC"
       label_date(date_labels, tz)(x)

From c518dee248025e51072bee713973e0d1e4448112 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Tue, 10 Sep 2024 10:03:55 +0200
Subject: [PATCH 3/4] add tests

---
 tests/testthat/test-scale-date.R | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/tests/testthat/test-scale-date.R b/tests/testthat/test-scale-date.R
index 1183fcd756..fe0ba380d8 100644
--- a/tests/testthat/test-scale-date.R
+++ b/tests/testthat/test-scale-date.R
@@ -69,7 +69,7 @@ test_that("datetime colour scales work", {
   expect_equal(range(get_layer_data(p)$colour), c("#132B43", "#56B1F7"))
 })
 
-test_that("date(time) scales throw warnings when input is numeric", {
+test_that("date(time) scales throw warnings when input is incorrect", {
   p <- ggplot(data.frame(x = 1, y = 1), aes(x, y)) + geom_point()
 
   expect_warning(
@@ -82,4 +82,19 @@ test_that("date(time) scales throw warnings when input is numeric", {
     "The value was converted to a <POSIXt/POSIXct> object."
   )
 
+  expect_error(
+    ggplot_build(p + scale_x_date(date_breaks = c(11, 12))),
+    "must be a single string"
+  )
+
+  expect_error(
+    ggplot_build(p + scale_x_date(date_minor_breaks = c(11, 12))),
+    "must be a single string"
+  )
+
+  expect_error(
+    ggplot_build(p + scale_x_date(date_labels = c(11, 12))),
+    "must be a single string"
+  )
+
 })

From 2cef6bb82ccc8fcc9a7748d0cd7803260c885cbf Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Tue, 10 Sep 2024 10:05:26 +0200
Subject: [PATCH 4/4] add news bullet

---
 NEWS.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/NEWS.md b/NEWS.md
index 4c0ea1e891..0c770eba94 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,7 @@
 # ggplot2 (development version)
 
+* Date(time) scales now throw appropriate errors when `date_breaks`, 
+  `date_minor_breaks` or `date_labels` are not strings (@RodDalBen, #5880)
 * Missing values from discrete palettes are no longer translated 
   (@teunbrand, #5929).
 * Fixed bug in `facet_grid(margins = TRUE)` when using expresssions