2 files changed, 30 insertions, 1 deletions
diff --git a/Makefile b/Makefile
index 73f8388..ebe2e2d 100644
--- a/Makefile
+++ b/Makefile
@@ -3,16 +3,25 @@ CFLAGS=-Wall -Wextra -Wpedantic -O3 -D_POSIX_C_SOURCE=200809L
 PREFIX=/usr/local
 BINDIR=$(PREFIX)/bin
 
+
 all: nt
 
+
 clean:
 	rm -f nt
 
+
+test: all
+	@./test.sh
+
+
 install: all
 	install -Dm755 nt -t $(DESTDIR)$(BINDIR)/
 
+
 uninstall:
 	rm -f $(DESTDIR)$(BINDIR)/nt
 
+
 .POSIX:
-.PHONY: clean install uninstall
+.PHONY: all clean test install uninstall
diff --git a/test.sh b/test.sh
new file mode 100755
index 0000000..14874b4
--- /dev/null
+++ b/test.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+nt_() {
+	./nt "$@"
+} >/dev/null
+
+
+fail() {
+	echo "$@"
+	exit 1
+} >&2
+
+
+nt_ && fail "shall return non-zero exit code on no args"
+nt_ 0 && fail "shall return non-zero exit code on just one arg"
+nt_ 0 - && fail "shall return non-zero exit code on zero reps"
+nt_ -1 - && fail "shall return non-zero exit code on negative reps"
+nt_ abc - && fail "shall return non-zero exit code on invalid number"
+nt_ 20 - || fail "shall return zero exit code with one component to repeat"
+nt_ 10 - = + || fail "shall return zero exit code with more components"
+echo ok