diff --git a/fileutil/testdata/demo.csv b/fileutil/testdata/demo.csv
new file mode 100644
index 0000000..8523fab
--- /dev/null
+++ b/fileutil/testdata/demo.csv
@@ -0,0 +1,3 @@
+Bob, 12, male
+Duke, 14, male
+Lucy, 16, female
diff --git a/fileutil/testdata/test1.csv b/fileutil/testdata/test1.csv
new file mode 100644
index 0000000..c8961e7
--- /dev/null
+++ b/fileutil/testdata/test1.csv
@@ -0,0 +1,2 @@
+Lili,22,female
+Jim,21,male
diff --git a/fileutil/testdata/test2.csv b/fileutil/testdata/test2.csv
new file mode 100644
index 0000000..c8961e7
--- /dev/null
+++ b/fileutil/testdata/test2.csv
@@ -0,0 +1,2 @@
+Lili,22,female
+Jim,21,male