1 files changed, 54 insertions, 3 deletions
diff --git a/tests/tap/perl/Test/RRA.pm b/tests/tap/perl/Test/RRA.pm
index 8608e31..807508c 100644
--- a/tests/tap/perl/Test/RRA.pm
+++ b/tests/tap/perl/Test/RRA.pm
@@ -5,6 +5,8 @@
 # by both C packages with Automake and by stand-alone Perl modules.  See
 # Test::RRA::Automake for additional functions specifically for C Automake
 # distributions.
+#
+# SPDX-License-Identifier: MIT
 
 package Test::RRA;
 
@@ -13,6 +15,7 @@ use strict;
 use warnings;
 
 use Exporter;
+use File::Temp;
 use Test::More;
 
 # For Perl 5.006 compatibility.
@@ -26,12 +29,56 @@ our (@EXPORT_OK, @ISA, $VERSION);
 # consistency is good).
 BEGIN {
     @ISA       = qw(Exporter);
-    @EXPORT_OK = qw(skip_unless_author skip_unless_automated use_prereq);
+    @EXPORT_OK = qw(
+      is_file_contents skip_unless_author skip_unless_automated use_prereq
+    );
 
     # This version should match the corresponding rra-c-util release, but with
     # two digits for the minor version, including a leading zero if necessary,
     # so that it will sort properly.
-    $VERSION = '5.10';
+    $VERSION = '7.02';
+}
+
+# Compare a string to the contents of a file, similar to the standard is()
+# function, but to show the line-based unified diff between them if they
+# differ.
+#
+# $got      - The output that we received
+# $expected - The path to the file containing the expected output
+# $message  - The message to use when reporting the test results
+#
+# Returns: undef
+#  Throws: Exception on failure to read or write files or run diff
+sub is_file_contents {
+    my ($got, $expected, $message) = @_;
+
+    # If they're equal, this is simple.
+    open(my $fh, '<', $expected) or BAIL_OUT("Cannot open $expected: $!\n");
+    my $data = do { local $/ = undef; <$fh> };
+    close($fh) or BAIL_OUT("Cannot close $expected: $!\n");
+    if ($got eq $data) {
+        is($got, $data, $message);
+        return;
+    }
+
+    # Otherwise, we show a diff, but only if we have IPC::System::Simple.
+    eval { require IPC::System::Simple };
+    if ($@) {
+        ok(0, $message);
+        return;
+    }
+
+    # They're not equal.  Write out what we got so that we can run diff.
+    my $tmp     = File::Temp->new();
+    my $tmpname = $tmp->filename;
+    print {$tmp} $got or BAIL_OUT("Cannot write to $tmpname: $!\n");
+    my @command = ('diff', '-u', $expected, $tmpname);
+    my $diff = IPC::System::Simple::capturex([0 .. 1], @command);
+    diag($diff);
+
+    # Remove the temporary file and report failure.
+    ok(0, $message);
+    return;
 }
 
 # Skip this test unless author tests are requested.  Takes a short description
@@ -225,10 +272,14 @@ SOFTWARE.
 Test::More(3), Test::RRA::Automake(3), Test::RRA::Config(3)
 
 This module is maintained in the rra-c-util package.  The current version is
-available from L<http://www.eyrie.org/~eagle/software/rra-c-util/>.
+available from L<https://www.eyrie.org/~eagle/software/rra-c-util/>.
 
 The functions to control when tests are run use environment variables defined
 by the L<Lancaster
 Consensus|https://github.com/Perl-Toolchain-Gang/toolchain-site/blob/master/lancaster-consensus.md>.
 
 =cut
+
+# Local Variables:
+# copyright-at-end-flag: t
+# End: