Add tests for plot_theme

Author: has2k1

R/theme.r

@@ -415,14 +415,14 @@ theme <- function(line,
 
 
 # Combine plot defaults with current theme to get complete theme for a plot
-plot_theme <- function(x) {
+plot_theme <- function(x, default_theme=theme_get()) {
   complete <- attr(x$theme, "complete")
   if (is.null(complete)) {
-    theme_get()
+    default_theme
   } else if (complete) {
     x$theme
   } else {
-    defaults(x$theme, theme_get())
+    defaults(x$theme, default_theme)
   }
 }
 

tests/testthat/test-theme.r

@@ -163,6 +163,20 @@ test_that("Complete and non-complete themes interact correctly with ggplot objec
   expect_false(attr(p$plot$theme, "complete"))
   expect_equal(p$plot$theme$text$colour, "red")
   expect_equal(p$plot$theme$text$face, "italic")
+
+  # The final calculated plot theme should not blend a complete theme
+  # with the default theme
+  default_theme <- theme_gray() + theme(axis.text.x = element_text(colour = "red"))
+
+  ptheme <- plot_theme(qplot(1:3, 1:3) + theme_void(), default_theme)
+  expect_null(ptheme$axis.text.x)
+
+  ptheme <- plot_theme(qplot(1:3, 1:3) + theme_gray(), default_theme)
+  expect_true(is.null(ptheme$axis.text.x$colour) || ptheme$axis.text.x$colour != "red")
+
+  ptheme <- plot_theme(qplot(1:3, 1:3) + theme(axis.text.y = element_text(colour = "blue")), default_theme)
+  expect_equal(ptheme$axis.text.x$colour, "red")
+  expect_equal(ptheme$axis.text.y$colour, "blue")
 })
 
 test_that("theme(validate=FALSE) means do not validate_element", {