Add basic tests for echo(1)

Verify that echo(1) does not...
- ... print the trailing newline character with option '-n'.
- ... print the trailing newline character when '\c' is appended to
      the end of the string.

Submitted by:	shivansh
Reviewed by:	asomers, ngie
MFC after:	1 month
Sponsored by:	Google, Inc (GSoC 2017)
Differential Revision:	D11036

bin/echo/Makefile

@@ -1,7 +1,13 @@
 #	@(#)Makefile	8.1 (Berkeley) 5/31/93
 # $FreeBSD$
 
+.include <src.opts.mk>
+
 PACKAGE=runtime
 PROG=	echo
 
+.if ${MK_TESTS} != "no"
+SUBDIR+= 	tests
+.endif
+
 .include <bsd.prog.mk>

bin/echo/tests/Makefile

@@ -0,0 +1,5 @@
+# $FreeBSD$
+
+ATF_TESTS_SH+=  echo_test
+
+.include <bsd.test.mk>

bin/echo/tests/echo_test.sh

@@ -0,0 +1,55 @@
+#
+# Copyright 2017 Shivansh Rai
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+# $FreeBSD$
+#
+
+atf_test_case n_output
+n_output_head() {
+        atf_set "descr" "Verify that echo(1) does not print the trailing " \
+                "newline character with option '-n'"
+}
+
+n_output_body() {
+        atf_check -s ignore -o inline:"Hello world" \
+                /bin/echo -n "Hello world"
+}
+
+atf_test_case append_c_output
+append_c_output_head() {
+        atf_set "descr" "Verify that echo(1) does not print the trailing newline " \
+                "character when '\c' is appended to the end of the string"
+}
+
+append_c_output_body() {
+        atf_check -s ignore -o inline:"Hello world" \
+                /bin/echo "Hello world\c"
+}
+
+atf_init_test_cases()
+{
+        atf_add_test_case n_output
+        atf_add_test_case append_c_output
+}

etc/mtree/BSD.tests.dist

@@ -12,6 +12,8 @@
         ..
         dd
         ..
+        echo
+        ..
         expr
         ..
         ls