tests: Add a test driver that prints fail logs to console

tests/Makefile.am

@@ -3,6 +3,14 @@ SUBDIRS = data
 AM_CFLAGS = $(CHAFA_CFLAGS) $(GLIB_CFLAGS)
 LDADD = $(GLIB_LIBS) $(top_builddir)/chafa/libchafa.la
 
+## --- Test driver ---
+
+# Our custom test driver is based on Automake's, with the addition that
+# it will print logs of failed tests to the console. This simplifies log
+# perusal in build systems. Requires Automake 1.12+.
+
+LOG_DRIVER = $(top_srcdir)/tests/test-driver.sh
+
 ## --- Backend tests ---
 
 noinst_PROGRAMS = \
@@ -45,4 +53,5 @@ AM_CPPFLAGS = \
 EXTRA_DIST = \
 	$(TOOL_CHECKS) \
 	chafa-tool-gallery.sh \
-	chafa-tool-test-common.sh
+	chafa-tool-test-common.sh \
+	test-driver.sh

tests/test-driver.sh

@@ -0,0 +1,163 @@
+#! /bin/sh
+# test-driver - basic testsuite driver script.
+
+scriptversion=2018-03-07.03; # UTC
+
+# Copyright (C) 2011-2021 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+# As a special exception to the GNU General Public License, if you
+# distribute this file as part of a program that contains a
+# configuration script generated by Autoconf, you may include it under
+# the same distribution terms that you use for the rest of that program.
+
+# This file is maintained in Automake, please report
+# bugs to <bug-automake@gnu.org> or send patches to
+# <automake-patches@gnu.org>.
+
+# Make unconditional expansion of undefined variables an error.  This
+# helps a lot in preventing typo-related bugs.
+set -u
+
+usage_error ()
+{
+  echo "$0: $*" >&2
+  print_usage >&2
+  exit 2
+}
+
+print_usage ()
+{
+  cat <<END
+Usage:
+  test-driver --test-name NAME --log-file PATH --trs-file PATH
+              [--expect-failure {yes|no}] [--color-tests {yes|no}]
+              [--enable-hard-errors {yes|no}] [--]
+              TEST-SCRIPT [TEST-SCRIPT-ARGUMENTS]
+
+The '--test-name', '--log-file' and '--trs-file' options are mandatory.
+See the GNU Automake documentation for information.
+END
+}
+
+test_name= # Used for reporting.
+log_file=  # Where to save the output of the test script.
+trs_file=  # Where to save the metadata of the test run.
+expect_failure=no
+color_tests=no
+enable_hard_errors=yes
+while test $# -gt 1; do
+ arg=${1%=*}
+ val=${1#*=}
+ if [ $arg = $val ]; then
+   val=$2
+   shift
+ fi
+ case $arg in
+  --help) print_usage; exit $?;;
+  --version) echo "test-driver $scriptversion"; exit $?;;
+  --test-name) test_name=$val;;
+  --log-file) log_file=$val;;
+  --trs-file) trs_file=$val;;
+  --color-tests) color_tests=$val;;
+  --expect-failure) expect_failure=$val;;
+  --enable-hard-errors) enable_hard_errors=$val;;
+  --) break;;
+  -*) usage_error "invalid option: '$1'";;
+  esac
+  [ $arg != $val ] && shift
+done
+
+missing_opts=
+test x"$test_name" = x && missing_opts="$missing_opts --test-name"
+test x"$log_file"  = x && missing_opts="$missing_opts --log-file"
+test x"$trs_file"  = x && missing_opts="$missing_opts --trs-file"
+if test x"$missing_opts" != x; then
+  usage_error "the following mandatory options are missing:$missing_opts"
+fi
+
+if test $# -eq 0; then
+  usage_error "missing argument"
+fi
+
+if test $color_tests = yes; then
+  # Keep this in sync with 'lib/am/check.am:$(am__tty_colors)'.
+  red='' # Red.
+  grn='' # Green.
+  lgn='' # Light green.
+  blu='' # Blue.
+  mgn='' # Magenta.
+  std=''     # No color.
+else
+  red= grn= lgn= blu= mgn= std=
+fi
+
+do_exit='rm -f $log_file $trs_file; (exit $st); exit $st'
+trap "st=129; $do_exit" 1
+trap "st=130; $do_exit" 2
+trap "st=141; $do_exit" 13
+trap "st=143; $do_exit" 15
+
+# Test script is run here. We create the file first, then append to it,
+# to ameliorate tests themselves also writing to the log file. Our tests
+# don't, but others can (automake bug#35762).
+: >"$log_file"
+"$@" >>"$log_file" 2>&1
+estatus=$?
+
+if test $enable_hard_errors = no && test $estatus -eq 99; then
+  tweaked_estatus=1
+else
+  tweaked_estatus=$estatus
+fi
+
+case $tweaked_estatus:$expect_failure in
+  0:yes) col=$red res=XPASS recheck=yes gcopy=yes;;
+  0:*)   col=$grn res=PASS  recheck=no  gcopy=no;;
+  77:*)  col=$blu res=SKIP  recheck=no  gcopy=yes;;
+  99:*)  col=$mgn res=ERROR recheck=yes gcopy=yes;;
+  *:yes) col=$lgn res=XFAIL recheck=no  gcopy=yes;;
+  *:*)   col=$red res=FAIL  recheck=yes gcopy=yes;;
+esac
+
+# Report the test outcome and exit status in the logs, so that one can
+# know whether the test passed or failed simply by looking at the '.log'
+# file, without the need of also peaking into the corresponding '.trs'
+# file (automake bug#11814).
+echo "$res $test_name (exit status: $estatus)" >>"$log_file"
+
+# Report outcome to console.
+echo "${col}${res}${std}: $test_name"
+
+# Chafa-specific: On error, print log file to console.
+if test $estatus != 0; then
+  cat "$log_file"
+fi
+
+# Register the test result, and other relevant metadata.
+echo ":test-result: $res" > $trs_file
+echo ":global-test-result: $res" >> $trs_file
+echo ":recheck: $recheck" >> $trs_file
+echo ":copy-in-global-log: $gcopy" >> $trs_file
+
+# Local Variables:
+# mode: shell-script
+# sh-indentation: 2
+# eval: (add-hook 'before-save-hook 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-time-zone: "UTC0"
+# time-stamp-end: "; # UTC"
+# End: