Merge pull request #22 from lionel-/release-0.1.2

Release 0.1.2

Author: lionel-

.Rbuildignore

@@ -4,3 +4,4 @@
 ^\.travis\.yml$
 ^cran-comments\.md$
 ^appveyor\.yml$
+^revdep$

.travis.yml

@@ -17,6 +17,7 @@ matrix:
         "sudo apt-get update -q",
         "sudo apt-get install libfreetype6"
       ]
+    - r: devel
     - os: osx
       osx_image: xcode7.2
       brew_packages: cairo

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: vdiffr
 Title: Visual Regression Testing and Graphical Diffing
-Version: 0.1.1.9000
+Version: 0.2.0
 Authors@R: c(
     person("Lionel", "Henry", , "[email protected]", c("cre", "aut")),
     person("RStudio", role = "cph"),
@@ -14,6 +14,11 @@ Authors@R: c(
 Description: An extension to the 'testthat' package that makes it easy
     to add graphical unit tests. It provides a Shiny application to
     manage the test cases.
+License: GPL-3 | file LICENSE
+LazyData: true
+ByteCompile: true
+SystemRequirements:
+    FreeType >= 2.6.0
 Depends:
     R (>= 3.1.0)
 Imports:
@@ -34,9 +39,8 @@ Imports:
 Suggests:
     ggplot2,
     roxygen2,
-    rstudioapi
-License: GPL-3 | file LICENSE
-LazyData: true
+    rstudioapi,
+    yaml
+LinkingTo:
+    Rcpp
 RoxygenNote: 6.0.1
-LinkingTo: Rcpp
-SystemRequirements: FreeType >= 2.6.0

NAMESPACE

@@ -25,6 +25,7 @@ export(widget_toggle)
 export(widget_toggle_)
 import(rlang)
 importFrom(R6,R6Class)
+importFrom(Rcpp,sourceCpp)
 importFrom(glue,glue)
 importFrom(purrr,every)
 importFrom(purrr,keep)
@@ -33,4 +34,4 @@ importFrom(purrr,map2_chr)
 importFrom(purrr,map_chr)
 importFrom(purrr,partial)
 importFrom(purrr,walk)
-useDynLib(vdiffr)
+useDynLib(vdiffr, .registration = TRUE)

NEWS.md

@@ -1,7 +1,13 @@
 
-# vdiffr 0.1.1.9000
+# vdiffr 0.2.0
 
-* Set minimal R version required to 3.1.0.
+This release makes it easier to debug failures on remote systems. It
+also makes vdiffr more robust to failures caused by incompatible
+installations: instead of failing, the tests are skipped. This
+prevents spurious failures on CRAN.
+
+
+## Troubleshooting on remotes
 
 * `expect_doppelganger()` gains a `verbose` argument to print the
   SVG files for failed cases while testing. This is useful to debug
@@ -14,6 +20,33 @@
   remotes.
 
 
+## Handling of incompatible systems
+
+The tests are now skipped if the FreeType version used to build the
+comparison SVGs does not match the version installed on the system
+where the tests are run. This is necessary because changes in new
+version of FreeType might affect the computation of text extents,
+which then causes svglite to produce slightly different SVGs. The
+minor version is not taken into account so FreeType 2.7.1 is deemed
+compatible with 2.7.2 but not with 2.8.0.
+
+In practice, this means that package contributors should only
+validate visual cases if their FreeType version matches the one of
+the package maintainer. Also, the maintainer must update the version
+recorded in the package repository (in the file
+`./tests/figs/deps.txt`) when FreeType has been updated on their
+system. Running `vdiffr::validate_cases()` updates the dependency
+file even if there are no visual case to update.
+
+In the future, we may provide a version of vdiffr statically
+compiled with a specific version of FreeType to prevent these issues.
+
+
+## Other changes
+
+* The minimal R version required by vdiffr is now R 3.1.0.
+
+
 # vdiffr 0.1.1
 
 * `expect_doppelganger()` no longer throws an error when FreeType is

R/RcppExports.R

@@ -2,6 +2,6 @@
 # Generator token: 10BE3573-1514-4C36-9D1C-5A225CD40393
 
 compare_files <- function(expected, test) {
-    .Call('_vdiffr_compare_files', PACKAGE = 'vdiffr', expected, test)
+    .Call(`_vdiffr_compare_files`, expected, test)
 }
 

R/cases.R

@@ -107,12 +107,23 @@ validate_cases <- function(cases = collect_new_cases()) {
 }
 
 write_deps_note <- function(cases, pkg_path) {
+  versions_lines <- glue(
+    "Fontconfig: { gdtools::version_fontconfig() }
+     FreeType: { gdtools::version_freetype() }
+     Cairo: { gdtools::version_cairo() }"
+  )
+
   deps <- attr(cases, "deps")
   versions <- map_chr(deps, package_version)
-  deps <- map2_chr(deps, versions, paste, sep = ": ")
+  deps_lines <- map2_chr(deps, versions, paste, sep = ": ")
+
+  deps_lines <- chr_lines(
+    versions_lines,
+    deps_lines
+  )
 
   deps_note_file <- file.path(pkg_path, "tests", "figs", "deps.txt")
-  writeLines(deps, deps_note_file)
+  writeLines(deps_lines, deps_note_file)
 }
 
 update_case <- function(case, pkg_path) {

R/testthat-ui.R

@@ -83,7 +83,7 @@ expect_doppelganger <- function(title, fig, path = NULL, ...,
     maybe_collect_case(case)
     maybe_print_svgs(case)
     msg <- paste0("Figure not generated yet: ", fig_name, ".svg")
-    exp <- expectation_new(msg, case)
+    exp <- new_exp(msg, case)
   }
 
   signal_expectation(exp)
@@ -104,18 +104,68 @@ compare_figs <- function(case) {
   if (equal) {
     case <- success_case(case)
     maybe_collect_case(case)
-    exp <- expectation_match("TRUE", case)
-  } else {
-    case <- mismatch_case(case)
-    maybe_collect_case(case)
+    return(match_exp("TRUE", case))
+  }
+
+  case <- mismatch_case(case)
+  maybe_collect_case(case)
+  push_log(case)
+
+  cases_ver <- cases_freetype_version()
+  system_ver <- system_freetype_version()
+
+  if (is_null(cases_ver)) {
+    msg <- glue(
+      "Failed doppelganger but vdiffr can't check its FreeType version.
+       Please revalidate cases with a more recent vdiffr"
+    )
+    return(skipped_mismatch_exp(msg, case))
+  }
+
+  if (cases_ver < system_ver) {
+    msg <- glue(
+      "Failed doppelganger was generated with an older FreeType version.
+       Please revalidate cases with vdiffr::validate_cases() or vdiffr::manage_cases()"
+    )
+    return(skipped_mismatch_exp(msg, case))
+  }
+
+  if (cases_ver > system_ver) {
+    msg <- glue(
+      "Failed doppelganger was generated with a newer FreeType version.
+       Please install FreeType {cases_ver} on your system"
+    )
+    return(skipped_mismatch_exp(msg, case))
+  }
+
+  msg <- paste0("Figures don't match: ", case$name, ".svg\n")
+  mismatch_exp(msg, case)
+}
 
-    msg <- paste0("Figures don't match: ", case$name, ".svg\n")
-    exp <- expectation_mismatch(msg, case)
+# Go back up one level by default as we should be in the `testthat`
+# folder
+cases_freetype_version <- function(path = "..") {
+  deps <- readLines(file.path(path, "figs", "deps.txt"))
+  ver <- purrr::detect(deps, function(dep) grepl("^FreeType:", dep))
 
-    push_log(case)
+  if (is_null(ver)) {
+    return(NULL)
   }
 
-  exp
+  # Strip "FreeType: " prefix and minor version
+  ver <- substr(ver, 11, nchar(ver))
+  ver <- sub(".[0-9]+$", "", ver)
+
+  as_version(ver)
+}
+system_freetype_version <- function() {
+  ver <- sub(".[0-9]+$", "", gdtools::version_freetype())
+  as_version(ver)
+}
+as_version <- function(ver) {
+  ver <- strsplit(ver, ".", fixed = TRUE)[[1]]
+  ver <- as.integer(ver)
+  structure(list(ver), class = c("package_version", "numeric_version"))
 }
 
 # Print only if we're not collecting. The testthat reporter prints
@@ -126,20 +176,22 @@ maybe_print_svgs <- function(case, pkg_path = NULL) {
   }
 }
 
-expectation_new <- function(msg, case) {
-  exp <- testthat::expectation("skip", msg)
-  classes <- c(class(exp), "vdiffr_new")
+new_expectation <- function(msg, case, type, vdiffr_type) {
+  exp <- testthat::expectation(type, msg)
+  classes <- c(class(exp), vdiffr_type)
   set_attrs(exp, class = classes, vdiffr_case = case)
 }
-expectation_mismatch <- function(msg, case) {
-  exp <- testthat::expectation("failure", msg)
-  classes <- c(class(exp), "vdiffr_mismatch")
-  set_attrs(exp, class = classes, vdiffr_case = case)
+new_exp <- function(msg, case) {
+  new_expectation(msg, case, "skip", "vdiffr_new")
 }
-expectation_match <- function(msg, case) {
-  exp <- testthat::expectation("success", msg)
-  classes <- c(class(exp), "vdiffr_match")
-  set_attrs(exp, class = classes, vdiffr_case = case)
+match_exp <- function(msg, case) {
+  new_expectation(msg, case, "success", "vdiffr_match")
+}
+mismatch_exp <- function(msg, case) {
+  new_expectation(msg, case, "failure", "vdiffr_mismatch")
+}
+skipped_mismatch_exp <- function(msg, case) {
+  new_expectation(msg, case, "skip", "vdiffr_mismatch")
 }
 
 # From testthat

R/vdiffr.R

@@ -2,8 +2,9 @@
 #' @importFrom glue glue
 #' @importFrom purrr map map_chr keep walk every partial map2_chr
 #' @importFrom R6 R6Class
-#' @useDynLib vdiffr
-NULL
+#' @importFrom Rcpp sourceCpp
+#' @useDynLib vdiffr, .registration = TRUE
+"_PACKAGE"
 
 old_freetype <- function() {
   gdtools::version_freetype() < "2.6.0"

README.md

@@ -139,50 +139,28 @@ C-v`, include something like this in your init file:
 
 ## Technical Aspects
 
-### Continuous integration on Travis
-
-To work properly, vdiffr requires the C library `FreeType` version
-2.6.0 or later. The FreeType libraries available by default on Travis'
-Linux platforms are not this recent yet. Some adjustments to the
-`travis.yml` file are thus required.
-
-**Ubuntu Precise (the default):**
-
-```{yaml}
-addons:
-  apt:
-    sources:
-      - debian-sid
-    packages:
-      - libfreetype6
-```
-
-**Ubuntu Trusty:**
-
-```{yaml}
-sudo: required
-before_install: [
-  "sudo add-apt-repository \"deb http://archive.ubuntu.com/ubuntu/ xenial main\" -y",
-  "sudo apt-get update -q",
-  "sudo apt-get install libfreetype6"
-]
-```
-
-**macOS with XCode 6.1:**
-
-```{yaml}
-osx_image: beta-xcode6.1
-disable_homebrew: true
-latex: false
-```
-
-**macOS with XCode 7.2:**
-
-```{yaml}
-osx_image: xcode7.2
-brew_packages: cairo
-latex: false
-```
+### FreeType dependency
+
+The software FreeType plays a key role in vdiffr. It is used to
+compute the extents of text boxes and thus determine the dimensions of
+graphical elements containing text. These dimensions are then recorded
+in the SVG files.
+
+Small changes in the algorithm implemented in FreeType to compute text
+extents will produce different SVGs. For this reason, it is important
+that the FreeType version that was used to create validated cases be
+the same as the one on the system running the tests. To avoid false
+failures, the visual tests are skipped when that's not the case. The
+minor version is not taken into account so FreeType 2.7.1 is deemed
+compatible with 2.7.2 but not with 2.8.0.
+
+In practice, this means that package contributors should only validate
+visual cases if their FreeType version matches the one of the package
+maintainer. Also, the maintainer must update the version recorded in
+the package repository (in the file `./tests/figs/deps.txt`) when
+FreeType has been updated on their system. Running
+`vdiffr::validate_cases()` updates the dependency file even if there
+are no visual case to update.
 
 
 ### Windows platforms