tests: Factor out a libtest-core.sh

This could be shared more easily with e.g. rpm-ostree, but what I'm currently
working on is installed, privileged (potentially destructive, i.e. VM) tests
that will source this separately from the current `libtest.sh`. That does work
installed, but in practice is oriented around unit (uninstalled, unprivileged)
tests.

Closes: #807
Approved by: jlebon

tests/libtest-core.sh

@@ -0,0 +1,111 @@
+# Core source library for shell script tests
+#
+# Copyright (C) 2017 Colin Walters <walters@verbum.org>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+fatal() {
+    echo $@ 1>&2; exit 1
+}
+# fatal() is shorter to type, but retain this alias
+assert_not_reached () {
+    fatal "$@"
+}
+
+# Some tests look for specific English strings. Use a UTF-8 version
+# of the C (POSIX) locale if we have one, or fall back to POSIX
+# (https://sourceware.org/glibc/wiki/Proposals/C.UTF-8)
+if locale -a | grep C.UTF-8 >/dev/null; then
+    export LC_ALL=C.UTF-8
+else
+    export LC_ALL=C
+fi
+
+# This should really be the default IMO
+export G_DEBUG=fatal-warnings
+assert_streq () {
+    test "$1" = "$2" || fatal "$1 != $2"
+}
+
+assert_str_match () {
+    if ! echo "$1" | grep -E -q "$2"; then
+	      fatal "$1 does not match regexp $2"
+    fi
+}
+
+assert_not_streq () {
+    (! test "$1" = "$2") || fatal "$1 == $2"
+}
+
+assert_has_file () {
+    test -f "$1" || fatal "Couldn't find '$1'"
+}
+
+assert_has_dir () {
+    test -d "$1" || fatal "Couldn't find '$1'"
+}
+
+assert_not_has_file () {
+    if test -f "$1"; then
+        sed -e 's/^/# /' < "$1" >&2
+        fatal "File '$1' exists"
+    fi
+}
+
+assert_not_file_has_content () {
+    if grep -q -e "$2" "$1"; then
+        sed -e 's/^/# /' < "$1" >&2
+        fatal "File '$1' incorrectly matches regexp '$2'"
+    fi
+}
+
+assert_not_has_dir () {
+    if test -d "$1"; then
+	      fatal "Directory '$1' exists"
+    fi
+}
+
+assert_file_has_content () {
+    if ! grep -q -e "$2" "$1"; then
+        sed -e 's/^/# /' < "$1" >&2
+        fatal "File '$1' doesn't match regexp '$2'"
+    fi
+}
+
+assert_symlink_has_content () {
+    if ! test -L "$1"; then
+        echo 1>&2 "File '$1' is not a symbolic link"
+        exit 1
+    fi
+    if ! readlink "$1" | grep -q -e "$2"; then
+        sed -e 's/^/# /' < "$1" >&2
+        echo 1>&2 "Symbolic link '$1' doesn't match regexp '$2'"
+        exit 1
+    fi
+}
+
+assert_file_empty() {
+    if test -s "$1"; then
+        sed -e 's/^/# /' < "$1" >&2
+        fatal "File '$1' is not empty"
+    fi
+}
+
+# Use to skip all of these tests
+skip() {
+    echo "1..0 # SKIP" "$@"
+    exit 0
+}