Initial tests

test/bats.bats

@@ -0,0 +1,21 @@
+#!/usr/bin/env bats
+
+FIXTURE_ROOT="$BATS_TEST_DIRNAME/fixtures"
+
+@test "running 'bats' with no arguments prints usage instructions" {
+  run bats
+  [[ $status -eq 1 ]]
+  [[ $output =~ ^usage: ]]
+}
+
+@test "running 'bats' with an invalid filename prints an error" {
+  run bats nonexistent
+  [[ $status -eq 1 ]]
+  [[ $output =~ does\ not\ exist ]]
+}
+
+@test "running 'bats' with an empty test file runs zero tests" {
+  run bats "$FIXTURE_ROOT/empty.bats"
+  [[ $status -eq 0 ]]
+  [[ $output = "1..0" ]]
+}