add append_meta

tests/test_fits_header_ops.py

@@ -19,6 +19,7 @@ from csst_common.io import (
     delete_section,
     get_proc_info,
     generate_meta,
+    append_meta,
 )
 
 
@@ -136,3 +137,10 @@ class TestFitsHeaderOps(unittest.TestCase):
     def test_generate_meta_with_invalid_args(self):
         with self.assertRaises(AssertionError):
             generate_meta(obs_id=1)
+
+    def test_append_meta(self):
+        hdulist = fits.HDUList()
+        hdulist.append(fits.PrimaryHDU())
+        hdulist = append_meta(hdulist, obs_id="123456")
+        self.assertIn("OBS_ID", hdulist[0].header)
+        self.assertEqual(hdulist[0].header["OBS_ID"], "123456")