Use vdiffr for visual unit tests (tidyverse#1874)

* Add vdiffr cases

* Generate test figures

* Silence warnings

* Add theme_test()

* Update to ggplot2 dev

* Update to latest svglite and vdiffr

* Update FreeType on Travis

* Update figures with latest master

* Reoxygenise and add NEWS bullet

* Use dev version of svglite

* Update visual cases to latest svglite

.travis.yml

@@ -2,6 +2,13 @@ language: R
 cache: packages
 sudo: false
 
+addons:
+  apt:
+    sources:
+      - debian-sid
+    packages:
+      - libfreetype6
+
 r_github_packages:
   - hadley/staticdocs@old
 

DESCRIPTION

@@ -36,6 +36,7 @@ Suggests:
     multcomp,
     nlme,
     testthat (>= 0.11.0),
+    vdiffr,
     quantreg,
     knitr,
     rpart,
@@ -217,3 +218,4 @@ Collate:
     'zzz.r'
 VignetteBuilder: knitr
 RoxygenNote: 6.0.0
+Remotes: hadley/svglite

NAMESPACE

@@ -476,6 +476,7 @@ export(theme_linedraw)
 export(theme_minimal)
 export(theme_replace)
 export(theme_set)
+export(theme_test)
 export(theme_update)
 export(theme_void)
 export(transform_position)

NEWS.md

@@ -1,5 +1,7 @@
 # ggplot2 2.2.1.9000
 
+* Automatic visual unit tests with vdiffr.
+
 * Layers no longer warn about unknown aesthetics who's value is set to 
   `NULL` (overriding a set aesthetic in the plot) (#1909).
 

R/theme-defaults.r

@@ -40,6 +40,10 @@
 #' \item{\code{theme_void}}{
 #' A completely empty theme.}
 #'
+#' \item{\code{theme_test}}{
+#' A theme for visual unit tests. It should ideally never change except
+#' for new features.}
+#'
 #' }
 #'
 #' @examples
@@ -341,3 +345,110 @@ theme_void <- function(base_size = 11, base_family = "") {
   )
 }
 
+#' @export
+#' @rdname ggtheme
+theme_test <- function(base_size = 11, base_family = "") {
+  half_line <- base_size / 2
+
+  theme(
+    line =               element_line(colour = "black", size = 0.5, linetype = 1,
+                            lineend = "butt"),
+    rect =               element_rect(fill = "white", colour = "black",
+                            size = 0.5, linetype = 1),
+    text =               element_text(
+                            family = base_family, face = "plain",
+                            colour = "black", size = base_size,
+                            lineheight = 0.9, hjust = 0.5, vjust = 0.5, angle = 0,
+                            margin = margin(), debug = FALSE
+                         ),
+
+    axis.line =          element_blank(),
+    axis.line.x =        NULL,
+    axis.line.y =        NULL,
+    axis.text =          element_text(size = rel(0.8), colour = "grey30"),
+    axis.text.x =        element_text(margin = margin(t = 0.8 * half_line / 2), vjust = 1),
+    axis.text.x.top =    element_text(margin = margin(b = 0.8 * half_line / 2), vjust = 0),
+    axis.text.y =        element_text(margin = margin(r = 0.8 * half_line / 2), hjust = 1),
+    axis.text.y.right =  element_text(margin = margin(l = 0.8 * half_line / 2), hjust = 0),
+    axis.ticks =         element_line(colour = "grey20"),
+    axis.ticks.length =  unit(half_line / 2, "pt"),
+    axis.title.x =       element_text(
+                           margin = margin(t = half_line),
+                           vjust = 1
+                         ),
+    axis.title.x.top =   element_text(
+                           margin = margin(b = half_line),
+                           vjust = 0
+                         ),
+    axis.title.y =       element_text(
+                           angle = 90,
+                           margin = margin(r = half_line),
+                           vjust = 1
+                         ),
+    axis.title.y.right = element_text(
+                           angle = -90,
+                           margin = margin(l = half_line),
+                           vjust = 0
+                         ),
+
+    legend.background =  element_rect(colour = NA),
+    legend.spacing =     unit(0.4, "cm"),
+    legend.spacing.x =   NULL,
+    legend.spacing.y =   NULL,
+    legend.margin =      margin(0, 0, 0, 0, "cm"),
+    legend.key =         element_rect(fill = "white", colour=NA),
+    legend.key.size =    unit(1.2, "lines"),
+    legend.key.height =  NULL,
+    legend.key.width =   NULL,
+    legend.text =        element_text(size = rel(0.8)),
+    legend.text.align =  NULL,
+    legend.title =       element_text(hjust = 0),
+    legend.title.align = NULL,
+    legend.position =    "right",
+    legend.direction =   NULL,
+    legend.justification = "center",
+    legend.box =         NULL,
+    legend.box.margin =  margin(0, 0, 0, 0, "cm"),
+    legend.box.background = element_blank(),
+    legend.box.spacing = unit(0.4, "cm"),
+
+    panel.background =   element_rect(fill = "white", colour = NA),
+    panel.border =       element_rect(fill = NA, colour = "grey20"),
+    panel.grid.major =   element_blank(),
+    panel.grid.minor =   element_blank(),
+    panel.spacing =      unit(half_line, "pt"),
+    panel.spacing.x =    NULL,
+    panel.spacing.y =    NULL,
+    panel.ontop    =     FALSE,
+
+    strip.background =   element_rect(fill = "grey85", colour = "grey20"),
+    strip.text =         element_text(colour = "grey10", size = rel(0.8)),
+    strip.text.x =       element_text(margin = margin(t = half_line, b = half_line)),
+    strip.text.y =       element_text(angle = -90, margin = margin(l = half_line, r = half_line)),
+    strip.placement =    "inside",
+    strip.placement.x =  NULL,
+    strip.placement.y =  NULL,
+    strip.switch.pad.grid = unit(0.1, "cm"),
+    strip.switch.pad.wrap = unit(0.1, "cm"),
+
+    plot.background =    element_rect(colour = "white"),
+    plot.title =         element_text(
+                           size = rel(1.2),
+                           hjust = 0, vjust = 1,
+                           margin = margin(b = half_line * 1.2)
+                         ),
+    plot.subtitle =      element_text(
+                           size = rel(0.9),
+                           hjust = 0, vjust = 1,
+                           margin = margin(b = half_line * 0.9)
+                         ),
+    plot.caption =       element_text(
+                           size = rel(0.9),
+                           hjust = 1, vjust = 1,
+                           margin = margin(t = half_line * 0.9)
+                         ),
+    plot.margin =        margin(half_line, half_line, half_line, half_line),
+
+    complete = TRUE
+  )
+}

appveyor.yml

@@ -12,6 +12,10 @@ install:
 
 # Adapt as necessary starting from here
 
+environment:
+  global:
+    USE_RTOOLS: true
+
 build_script:
   - travis-tool.sh install_deps