Added shell test for linting different file types

Signed-off-by: Ole Herman Schumacher Elgesem <ole@northern.tech>

Author: olehermanse

tests/shell/005-lint.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+
+set -e
+set -x
+
+# Setup: create a temp directory for test files
+tmpdir=$(mktemp -d)
+output_file=$(mktemp)
+trap "rm -rf $tmpdir $output_file" EXIT
+
+# Empty JSON file
+printf "" > "$tmpdir/empty.json"
+
+# Empty CSV file
+printf "" > "$tmpdir/empty.csv"
+
+# Empty policy file
+printf "" > "$tmpdir/empty.cf"
+
+# CSV with LF-only line endings
+printf 'a,b,c\n1,2,3\n' > "$tmpdir/bad.csv"
+
+# JSON with just some characters
+printf 'abc\n' > "$tmpdir/bad.json"
+
+# Policy file with just some characters
+printf 'abc\n' > "$tmpdir/bad.cf"
+
+# Run lint on the folder - expect non-zero exit
+if cfengine lint "$tmpdir" > "$output_file" 2>&1; then
+	cat "$output_file"
+	echo "FAIL: expected lint to fail, but it succeeded"
+	exit 1
+fi
+cat "$output_file"
+
+# Verify each file is reported as failing
+grep -q "FAIL:.*empty.json" "$output_file"
+grep -q "FAIL:.*empty.csv" "$output_file"
+grep -q "FAIL:.*empty.cf" "$output_file"
+grep -q "FAIL:.*bad.csv" "$output_file"
+grep -q "FAIL:.*bad.json" "$output_file"
+grep -q "FAIL:.*bad.cf" "$output_file"
+
+# Verify total error count is 6
+grep -q "Failure, 6 errors in total" "$output_file"