From 551c94cf7f0f059153c707bc695fd9df2e2309c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=A1bor=20Cs=C3=A1rdi?= <csardi.gabor@gmail.com>
Date: Mon, 25 Nov 2019 22:24:35 +0000
Subject: [PATCH] Add @examplesIf tag

---
 DESCRIPTION                           |  2 +-
 NAMESPACE                             |  2 ++
 R/rd-examples.R                       | 29 +++++++++++++++++++++++++++
 tests/testthat/test-rd-examples.R     | 15 ++++++++++++++
 tests/testthat/test-rd-examplesIf.txt | 10 +++++++++
 5 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 tests/testthat/test-rd-examplesIf.txt

diff --git a/DESCRIPTION b/DESCRIPTION
index 285d56bb0..cd4ceaee5 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -59,5 +59,5 @@ VignetteBuilder:
     knitr
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE, load = "installed")
-RoxygenNote: 7.0.0.9000
+RoxygenNote: 7.0.1.9000
 Language: en-GB
diff --git a/NAMESPACE b/NAMESPACE
index 93da52999..81bbd1d19 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -110,6 +110,7 @@ S3method(roxy_tag_parse,roxy_tag_evalNamespace)
 S3method(roxy_tag_parse,roxy_tag_evalRd)
 S3method(roxy_tag_parse,roxy_tag_example)
 S3method(roxy_tag_parse,roxy_tag_examples)
+S3method(roxy_tag_parse,roxy_tag_examplesIf)
 S3method(roxy_tag_parse,roxy_tag_export)
 S3method(roxy_tag_parse,roxy_tag_exportClass)
 S3method(roxy_tag_parse,roxy_tag_exportMethod)
@@ -165,6 +166,7 @@ S3method(roxy_tag_rd,roxy_tag_encoding)
 S3method(roxy_tag_rd,roxy_tag_evalRd)
 S3method(roxy_tag_rd,roxy_tag_example)
 S3method(roxy_tag_rd,roxy_tag_examples)
+S3method(roxy_tag_rd,roxy_tag_examplesIf)
 S3method(roxy_tag_rd,roxy_tag_family)
 S3method(roxy_tag_rd,roxy_tag_field)
 S3method(roxy_tag_rd,roxy_tag_format)
diff --git a/R/rd-examples.R b/R/rd-examples.R
index 0e3d955c4..b1e1c926d 100644
--- a/R/rd-examples.R
+++ b/R/rd-examples.R
@@ -3,6 +3,31 @@ roxy_tag_parse.roxy_tag_examples <- function(x) {
   tag_examples(x)
 }
 #' @export
+roxy_tag_parse.roxy_tag_examplesIf <- function(x) {
+  lines <- unlist(strsplit(x$raw, "\r?\n"))
+
+  condition <- lines[1]
+  tryCatch(
+    suppressWarnings(parse(text = condition)),
+    error = function(err) {
+      roxy_tag_warning(x, "failed to parse condition of @examplesIf")
+    }
+  )
+
+  dontshow <- paste0(
+    "\\dontshow{if (",
+    condition,
+    ") (if (getRversion() >= \"3.4\") withAutoprint else force)(\\{ # examplesIf}"
+  )
+
+  x$raw <- paste(
+    c(dontshow, lines[-1], "\\dontshow{\\}) # examplesIf}"),
+    collapse = "\n"
+  )
+
+  x <- tag_examples(x)
+}
+#' @export
 roxy_tag_parse.roxy_tag_example <- function(x) {
   x <- tag_value(x)
 
@@ -20,6 +45,10 @@ roxy_tag_rd.roxy_tag_examples <- function(x, base_path, env) {
   rd_section("examples", x$val)
 }
 #' @export
+roxy_tag_rd.roxy_tag_examplesIf <- function(x, base_path, env) {
+  rd_section("examples", x$val)
+}
+#' @export
 roxy_tag_rd.roxy_tag_example <- function(x, base_path, env) {
   path <- file.path(base_path, x$val)
   if (!file.exists(path)) {
diff --git a/tests/testthat/test-rd-examples.R b/tests/testthat/test-rd-examples.R
index be3809e2b..80dfa6b04 100644
--- a/tests/testthat/test-rd-examples.R
+++ b/tests/testthat/test-rd-examples.R
@@ -77,6 +77,21 @@ test_that("warns if path doesn't exist", {
   )
 })
 
+test_that("@examplesIf", {
+  out <- roc_proc_text(rd_roclet(), "
+    #' @name a
+    #' @title a
+    #' @examplesIf foo::bar()
+    #' maybe-run-this-code
+    #' @examplesIf foobar()
+    #' and-this
+    NULL")[[1]]
+
+  verify_output(test_path("test-rd-examplesIf.txt"), {
+    out$get_section("examples")
+  })
+})
+
 test_that("% in @examples escaped before matching braces test (#213)", {
   out <- roc_proc_text(rd_roclet(), "
     #' @name a
diff --git a/tests/testthat/test-rd-examplesIf.txt b/tests/testthat/test-rd-examplesIf.txt
new file mode 100644
index 000000000..ba7ad9c75
--- /dev/null
+++ b/tests/testthat/test-rd-examplesIf.txt
@@ -0,0 +1,10 @@
+> out$get_section("examples")
+\examples{
+\dontshow{if (foo::bar()) (if (getRversion() >= "3.4") withAutoprint else force)(\{ # examplesIf}
+maybe-run-this-code
+\dontshow{\}) # examplesIf}
+\dontshow{if (foobar()) (if (getRversion() >= "3.4") withAutoprint else force)(\{ # examplesIf}
+and-this
+\dontshow{\}) # examplesIf}
+} 
+