Use autoconf log compiler for test suite

Using the log compiler feature of autoconf will run the test runner for
each test-case instead of treating all test-cases as a single test.

Makefile.am

@@ -7,9 +7,15 @@ bin_PROGRAMS=src/pick
 dist_src_pick_SOURCES=src/pick.c src/compat.h src/compat.c
 dist_man_MANS=man/man1/pick.1
 
-TESTS=tests/test.sh
+TESTS=tests/01.t tests/02.t tests/03.t tests/04.t tests/05.t tests/06.t \
+      tests/07.t tests/08.t tests/09.t tests/10.t tests/11.t tests/12.t \
+      tests/13.t tests/14.t tests/15.t tests/16.t tests/17.t tests/18.t \
+      tests/19.t tests/20.t tests/21.t tests/22.t tests/23.t tests/24.t \
+      tests/25.t tests/26.t
+TEST_EXTENSIONS=.t
+T_LOG_COMPILER=sh tests/test.sh
 check_PROGRAMS=tests/test
-tests_test_SOURCES=tests/test.sh tests/test.c
+tests_test_SOURCES=tests/test.c
 # Required by posix_openpt on Linux.
 tests_test_CFLAGS=-D_XOPEN_SOURCE=600
 

tests/test.sh

@@ -1,5 +1,3 @@
-#!/bin/sh
-
 field() {
   awk '
   /^output:/ { sub(/\\n/, "\n"); }
@@ -22,7 +20,14 @@ pick() {
   $DIR/test -i "$input" -- $args <"$in"
 }
 
+usage() {
+  echo "usage: sh tests/test.sh file ..." 1>&2
+  exit 1
+}
+
 main() {
+  [ $# -eq 0 ] && usage
+
   DIR=$(dirname "$0")
   PATH="${DIR}/../src:${PATH}"
 
@@ -32,7 +37,6 @@ main() {
   err=$(mktemp -t pick.XXXXXX)
   trap 'rm "$in" "$exp" "$act" "$err"' EXIT
 
-  [ $# -eq 0 ] && set $(find "$DIR" -name '*.t')
   for a
   do
     e=$(field exit <"$a" || echo 0)