added expect_*_to_reference

pkg/DESCRIPTION

@@ -19,9 +19,9 @@ Description: Provides a lightweight (zero-dependency) and easy to use
     configurable output printing. Compare computed output with output stored 
     with the package. Run tests in parallel. Extensible by other packages.
     Report side effects.
-Version: 1.1.0.2
+Version: 1.1.0.3
 URL: https://github.com/markvanderloo/tinytest
 BugReports: https://github.com/markvanderloo/tinytest/issues
 Imports: parallel, utils
-RoxygenNote: 6.1.1
+RoxygenNote: 7.0.2
 Encoding: UTF-8

pkg/NAMESPACE

@@ -14,7 +14,9 @@ export(at_home)
 export(build_install_test)
 export(exit_file)
 export(expect_equal)
+export(expect_equal_to_reference)
 export(expect_equivalent)
+export(expect_equivalent_to_reference)
 export(expect_error)
 export(expect_false)
 export(expect_identical)

pkg/NEWS

@@ -1,4 +1,7 @@
 version 1.2.0
+- New functions 'expect_equal_to_reference' and 'expect_equivalent_to_reference'
+  comparing/storing an object with/to an RDS file (Thanks to Jon Clayden for 
+  suggesting).
 - Argument 'tol' now renamed 'tolerance'. Also removed internal reliance on
   partial argument matching (Thanks to Michel Lang).
 - Fix: test_package() would return NULL when called interactively and the package

pkg/R/expectations.R

@@ -498,6 +498,77 @@ expect_message <- function(current, pattern=".*", info=NA_character_){
 
 }
 
+#' Compare object with object stored in a file
+#'
+#' Compares the current value with a value stored to file with
+#' \code{\link{saveRDS}}.  If the  file does not exist, the current value is
+#' stored into file, and the test returns \code{expect_null(NULL)}.
+#'
+#' @param current \code{[R object or expression]} Outcome or expression under 
+#'        scrutiny.
+#' @param file \code{[character]} File where the \code{target} is stored. If 
+#'        \code{file} does not exist, \code{current} will be stored there.
+#' @param ... passed to \code{\link{expect_equal}}, respectively \code{\link{expect_equivalent}}.
+#'
+#' @note
+#' Be aware that on CRAN it is not allowed to write data to user space. So make
+#' sure that the file is either stored with your tests, or generated with
+#' \code{\link{tempfile}}, or the test is skipped on CRAN, using
+#' \code{\link{at_home}}.
+#' 
+#' Also note that \code{\link{build_install_test}} clones the package and
+#' builds and tests it in a separate R session in the background. This means
+#' that if you create a file located at \code{tempfile()} during the run, this
+#' file is destroyed when the separate R session is closed.
+#'
+#'
+#' @family test-functions
+#'
+#'
+#' @examples
+#' filename <- tempfile()
+#' # this gives TRUE: the file does not exist, but is created now.
+#' expect_equal_to_reference(1, file=filename)
+#' # this gives TRUE: the file now exists, and its contents is equal
+#' # to the current value
+#' expect_equal_to_reference(1, file=filename)
+#' # this gives FALSE: the file exists, but is contents is not equal
+#' # to the current value
+#' expect_equal_to_reference(2, file=filename)
+#'
+#' @export
+expect_equal_to_reference <- function(current, file, ...){
+  eetr(current=current, file=file, type="equal", ...)
+}
+
+#' @rdname expect_equal_to_reference
+#' @export
+expect_equivalent_to_reference <- function(current, file, ...){
+  eetr(current=current, file=file, type="equivalent", ...)
+}
+
+eetr <- function (current, file, type=c("equal","equivalent"), ...){
+
+    if (file.exists(file)){
+        out <- if (type=="equal")
+                  tinytest:::expect_equal(current, readRDS(file), ...)
+                else
+                  tinytest:::expect_equivalent(current, readRDS(file), ...)
+        if (!out){
+           diff <- attr(out, "diff")
+           diff <- paste(
+                    sprintf("current does not match target read from %s\n", file)
+                    , diff)
+           attr(out,"diff") <- diff
+        }
+        out
+    } else {
+        tinytest:::expect_null(saveRDS(current, file)
+                , info=sprintf("Stored value in %s", file))
+    }
+}
+
+
 
 #' Report side effects for expressions in test files
 #'

pkg/R/tinytest.R

@@ -227,6 +227,7 @@ add_locally_masked_functions <- function(envir, output){
   envir$expect_error        <- capture(expect_error, output)
   envir$expect_identical    <- capture(expect_identical, output)
   envir$expect_silent       <- capture(expect_silent, output)
+  envir$expect_equal_to_reference <- capture(expect_equal_to_reference, output)
   envir$exit_file           <- capture_exit(exit_file, output)
   envir$ignore              <- ignore
   envir$at_home             <- tinytest::at_home

pkg/inst/tinytest/test_tiny.R

@@ -33,6 +33,16 @@ expect_false(ignore(expect_equivalent)(2,c(x=3)))
 expect_true(ignore(expect_null)(NULL))
 expect_false(ignore(expect_null)(1))
 
+fl <- tempfile()
+expect_true(ignore(expect_equal_to_reference)(1, file=fl))
+expect_true(ignore(expect_equal_to_reference)(1, file=fl))
+expect_false(ignore(expect_equal_to_reference)(2, file=fl))
+
+xx <- c(fu=1)
+expect_true(ignore(expect_equivalent_to_reference)(xx, file=fl))
+expect_false(ignore(expect_equal_to_reference)(xx, file=fl))
+
+
 
 
 # reading from file