tests: Skip examples/tests if Python not detected

* We now skip examples/tests if we can't find our Python dependency
* We are observing a CRAN Check ERROR on the 'r-devel-windows-x86_64-gcc10-UCRT'
  flavor because it can't find our run-time Python dependency

R/argparse.R

@@ -1,4 +1,4 @@
-# Copyright (c) 2012-2020 Trevor L. Davis <[email protected]>
+# Copyright (c) 2012-2021 Trevor L. Davis <[email protected]>
 #
 #  This file is free software: you may copy, redistribute and/or modify it
 #  under the terms of the GNU General Public License as published by the
@@ -47,21 +47,23 @@
 #' @export
 #' @examples
 #'
-#' parser <- ArgumentParser(description='Process some integers')
-#' parser$add_argument('integers', metavar='N', type = "integer", nargs='+',
-#'                    help='an integer for the accumulator')
-#' parser$add_argument('--sum', dest='accumulate', action='store_const',
-#'                    const='sum', default='max',
-#'                    help='sum the integers (default: find the max)')
-#' parser$print_help()
-#' # default args for ArgumentParser()$parse_args are commandArgs(TRUE)
-#' # which is what you'd want for an Rscript but not for interactive use
-#' args <- parser$parse_args(c("--sum", "1", "2", "3"))
-#' accumulate_fn <- get(args$accumulate)
-#' print(accumulate_fn(args$integers))
+#' if (argparse:::detects_python()) {
+#'   parser <- ArgumentParser(description='Process some integers')
+#'   parser$add_argument('integers', metavar='N', type = "integer", nargs='+',
+#'                      help='an integer for the accumulator')
+#'   parser$add_argument('--sum', dest='accumulate', action='store_const',
+#'                      const='sum', default='max',
+#'                      help='sum the integers (default: find the max)')
+#'   parser$print_help()
+#'   # default args for ArgumentParser()$parse_args are commandArgs(TRUE)
+#'   # which is what you'd want for an Rscript but not for interactive use
+#'   args <- parser$parse_args(c("--sum", "1", "2", "3"))
+#'   accumulate_fn <- get(args$accumulate)
+#'   print(accumulate_fn(args$integers))
+#' }
 ArgumentParser <- function(..., python_cmd = NULL) { # nolint
-    python_cmd <- .find_python_cmd(python_cmd)
-    .assert_python_cmd(python_cmd)
+    python_cmd <- find_python_cmd(python_cmd)
+    assert_python_cmd(python_cmd)
     initial_python_code <- c("import argparse",
         "try:",
         "    import json",
@@ -294,17 +296,23 @@ get_Rscript_filename <- function() { # nolint
 
 # Internal function to check python cmd is okay
 # @param python_cmd Python cmd to use
-.assert_python_cmd <- function(python_cmd) {
+assert_python_cmd <- function(python_cmd) {
     if (!findpython::is_python_sufficient(python_cmd, required_modules = c("argparse", "json | simplejson"))) {
         stop(paste(sprintf("python executable %s either is not installed,", python_cmd),
                 "is not on the path, or does not have argparse, json modules",
                 "please see INSTALL file"))
     }
 }
 
+detects_python <- function() {
+    python_cmd <- find_python_cmd()
+    findpython::is_python_sufficient(python_cmd,
+                                     required_modules = c("argparse", "json | simplejson"))
+}
+
 # Internal function to find python cmd
 # @param python_cmd  Python cmd to use
-.find_python_cmd <- function(python_cmd) {
+find_python_cmd <- function(python_cmd = NULL) {
     if (is.null(python_cmd)) {
         python_cmd <- getOption("python_cmd")
     }

cran-comments.rst

@@ -1,7 +1,8 @@
-**Nota benes**
+## Notes
 
-* This update should fix the new ``r-devel-linux-x86-64-debian-gcc`` package check error
-  (seems to be result of non-reverse-compatible python update).
+* The examples and unit tests are now skipped if an appropriate
+  version of Python is not found as with the 'r-devel-windows-x86_64-gcc10-UCRT'
+  CRAN flavor.
 
 * As in previous uploads while in a non-interactive session (i.e. in an
   Rscript) if ``parse_args()`` observes a help flag it will print a usage
@@ -13,18 +14,21 @@
 * This package has a Python dependency most easily satisfied having (C)Python
   3.2 or greater on the PATH.  See file INSTALL for more details.
 
-**Test environments**
+## Test environments
 
-* local (linux), R 4.0.3
+* local (linux), R 4.1.0
 * win-builder (windows), R devel
-* appveyor (windows), R release and R devel
-* travis-ci (OSX), R release
-* travis-ci (linux), R release and R devel
+* Github Actions (linux), R release and R devel
+* Github Actions (windows), R release
+* Github Actions (OSX), R release
 
-**R CMD check --as-cran results**
+## R CMD check --as-cran results
 
 Status: OK
 
-**Downstream dependencies**
+## revdepcheck results
 
-This package does not have any downstream dependencies.
+We checked 3 reverse dependencies (0 from CRAN + 3 from Bioconductor), comparing R CMD check results across CRAN and dev versions of this package.
+
+ * We saw 0 new problems
+ * We failed to check 0 packages

tests/test_help.R → tests/testthat/scripts/test_help.R

@@ -1,3 +1,3 @@
 library("argparse")
 p <- ArgumentParser()
-p$parse_args("--help")
+p$parse_args()

tests/test_version.R → tests/testthat/scripts/test_version.R

@@ -1,4 +1,4 @@
 library("argparse")
 p <- ArgumentParser()
 p$add_argument("-v", "--version", action = "version", version = "1.0.1")
-p$parse_args("--version")
+p$parse_args()

tests/testthat/test-argparse.R

@@ -1,4 +1,4 @@
-# Copyright (c) 2012-2018 Trevor L Davis <[email protected]>
+# Copyright (c) 2012-2021 Trevor L Davis <[email protected]>
 #
 #  This file is free software: you may copy, redistribute and/or modify it
 #  under the terms of the GNU General Public License as published by the
@@ -21,10 +21,9 @@
 # Python (GPL-compatible) license stack.
 context("Unit tests")
 
-options(python_cmd = .find_python_cmd(NULL))
-# options(python_cmd = "/home/trevorld/tmp/python/Python-3.9.0/python") # nolint
 context("print_help")
 test_that("print_help works as expected", {
+    skip_if_not(detects_python())
     parser <- ArgumentParser(description = "Process some integers.")
     expect_output(parser$print_help(), "usage:")
     expect_output(parser$print_help(), "optional arguments:")
@@ -42,6 +41,7 @@ test_that("print_help works as expected", {
 
 context("convert_agument")
 test_that("convert_argument works as expected", {
+    skip_if_not(detects_python())
     expect_equal(convert_argument("foobar"), "'foobar'")
     expect_equal(convert_argument(14.9), "14.9")
     expect_equal(convert_argument(c(12.1, 14.9)), "(12.1, 14.9)")
@@ -50,6 +50,7 @@ test_that("convert_argument works as expected", {
 
 context("convert_..._to_arguments")
 test_that("convert_..._to_arguments works as expected", {
+    skip_if_not(detects_python())
     # test in mode "add_argument"
     c.2a <- function(...) convert_..._to_arguments("add_argument", ...)
     waz <- "wazzup"
@@ -71,6 +72,7 @@ test_that("convert_..._to_arguments works as expected", {
 
 context("add_argument")
 test_that("add_argument works as expected", {
+    skip_if_not(detects_python())
     parser <- ArgumentParser()
     parser$add_argument("integers", metavar = "N", type = "integer", nargs = "+",
                        help = "an integer for the accumulator")
@@ -119,6 +121,7 @@ test_that("add_argument works as expected", {
 
 context("version")
 test_that("version flags works as expected", {
+    skip_if_not(detects_python())
     # Feature request of Dario Beraldi
     parser <- ArgumentParser()
     parser$add_argument("-v", "--version", action = "version", version = "1.0.1")
@@ -136,6 +139,7 @@ test_that("version flags works as expected", {
 
 context("ArgumentParser")
 test_that("ArgumentParser works as expected", {
+    skip_if_not(detects_python())
     parser <- ArgumentParser(prog = "foobar", usage = "%(prog)s arg1 arg2")
     parser$add_argument("--hello", dest = "saying", action = "store_const",
             const = "hello", default = "bye",
@@ -149,7 +153,9 @@ test_that("ArgumentParser works as expected", {
     expect_error(ArgumentParser(add_help = TRUE)$parse_args("-h"), "help requested")
     expect_error(ArgumentParser(add_help = FALSE)$parse_args("-h"), "unrecognized arguments")
 })
+
 test_that("parse_args works as expected", {
+    skip_if_not(detects_python())
     parser <- ArgumentParser("foobar", usage = "%(prog)s arg1 arg2")
     parser$add_argument("--hello", dest = "saying", action = "store", default = "foo",
             choices = c("foo", "bar"),
@@ -192,6 +198,7 @@ test_that("parse_args works as expected", {
 # Bug found by Erick Rocha Fonseca
 context("Unicode arguments/options")
 test_that("Unicode support works if Python and OS sufficient", {
+    skip_if_not(detects_python())
     skip_on_os("windows") # Didn't work on win-builder
     skip_on_cran() # Didn't work on Debian Clang
     did_find_python3 <- findpython::can_find_python_cmd(minimum_version = "3.0",
@@ -202,7 +209,9 @@ test_that("Unicode support works if Python and OS sufficient", {
     p$add_argument("name")
     expect_equal(p$parse_args("\u8292\u679C"), list(name = "\u8292\u679C")) # 芒果
 })
+
 test_that("Unicode attempt throws error if Python or OS not sufficient", {
+    skip_if_not(detects_python())
     skip_on_os("windows") # Didn't work on AppVeyor
     skip_on_cran() # Didn't work on Debian Clang
     did_find_python2 <- findpython::can_find_python_cmd(maximum_version = "2.7",
@@ -218,6 +227,7 @@ test_that("Unicode attempt throws error if Python or OS not sufficient", {
 # Mutually exclusive groups is a feature request by Vince Reuter
 context("Mutually exclusive groups")
 test_that("mutually exclusive groups works as expected", {
+    skip_if_not(detects_python())
     parser <- ArgumentParser(prog = "PROG")
     group <- parser$add_mutually_exclusive_group()
     group$add_argument("--foo", action = "store_true")
@@ -240,6 +250,7 @@ test_that("mutually exclusive groups works as expected", {
 # argument groups is a feature request by Dario Beraldi
 context("Add argument group")
 test_that("add argument group works as expected", {
+    skip_if_not(detects_python())
     parser <- ArgumentParser(prog = "PROG", add_help = FALSE)
     group1 <- parser$add_argument_group("group1", "group1 description")
     group1$add_argument("foo", help = "foo help")
@@ -252,6 +263,7 @@ test_that("add argument group works as expected", {
 # subparser support is a feature request by Zebulun Arendsee
 context("Supparser support")
 test_that("sub parsers work as expected", {
+    skip_if_not(detects_python())
     # create the top-level parser
     parser <- ArgumentParser(prog = "PROG")
     parser$add_argument("--foo", action = "store_true", help = "foo help")
@@ -276,3 +288,20 @@ test_that("sub parsers work as expected", {
     expect_output(parser_a$print_help(), "usage: PROG a")
     expect_output(parser_b$print_help(), "usage: PROG b")
 })
+
+context("Paths that quit()")
+test_that("Paths that quit()", {
+    skip_if_not(detects_python())
+    skip_on_os("windows")
+    cmd <- file.path(R.home(), "bin/Rscript")
+    skip_if(Sys.which(cmd) == "")
+
+    expect_equal(system2(cmd, c("scripts/test_version.R", "--version"), stdout = TRUE),
+                 "1.0.1")
+
+    help <- system2(cmd, c("scripts/test_help.R", "--help"),
+                    stdout = TRUE, stderr = TRUE)
+    expect_equal(help,
+                 c("usage: scripts/test_help.R [-h]", "", "optional arguments:",
+                   "  -h, --help  show this help message and exit"))
+})