Refactored, added comprehensive testing.

input/stdin_test.go

@@ -0,0 +1,27 @@
+package input
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// Integration test helper - run manually with:
+// echo "test" | STDIN_TEST=1 go test ./input/ -run TestDetectStdinIntegration
+func TestDetectStdinIntegration(t *testing.T) {
+	if os.Getenv("STDIN_TEST") != "1" {
+		t.Skip("Set STDIN_TEST=1 and pipe data to run this test")
+	}
+
+	content, hasStdin := DetectStdin()
+
+	t.Logf("hasStdin: %v", hasStdin)
+	t.Logf("content length: %d", len(content))
+	t.Logf("content: %q", content)
+
+	// When piped: should detect stdin
+	if hasStdin {
+		assert.NotEmpty(t, content, "Expected content when stdin detected")
+	}
+}