Coverage for tests/test_fits_format_version.py: 26%

1# This file is part of lsst-images. 

2# 

3# Developed for the LSST Data Management System. 

4# This product includes software developed by the LSST Project 

5# (https://www.lsst.org). 

6# See the COPYRIGHT file at the top-level directory of this distribution 

7# for details of code ownership. 

8# 

9# Use of this source code is governed by a 3-clause BSD-style 

10# license that can be found in the LICENSE file. 

11 

12from __future__ import annotations 

13 

14import os 

15import tempfile 

16import unittest 

17 

18import astropy.io.fits 

19 

20from lsst.images import Image 

21from lsst.images.fits import FitsInputArchive 

22from lsst.images.serialization import ArchiveReadError 

23 

24 

25def _write_simple_image_fits(path: str) -> None: 

26 """Write a tiny Image to ``path`` via the high-level API.""" 

27 image = Image(0.0, shape=(4, 4), dtype="float32") 

28 image.write_fits(path) 

29 

30 

31class FitsFormatVersionTestCase(unittest.TestCase): 

32 """Tests for the FITS FMTVER and DATAMODL primary-header keywords.""" 

33 

34 def test_write_emits_fmtver_and_datamodl(self): 

35 """A freshly-written FITS carries FMTVER=1 and the root DATAMODL.""" 

36 with tempfile.TemporaryDirectory() as tmp: 

37 path = os.path.join(tmp, "x.fits") 

38 _write_simple_image_fits(path) 

39 with astropy.io.fits.open(path) as hdul: 

40 self.assertEqual(hdul[0].header["FMTVER"], 1) 

41 self.assertEqual( 

42 hdul[0].header["DATAMODL"], 

43 "https://images.lsst.io/schemas/image-1.0.0", 

44 ) 

45 

46 def test_read_succeeds_when_fmtver_matches(self): 

47 """Round-trip read of a freshly-written file succeeds without error.""" 

48 with tempfile.TemporaryDirectory() as tmp: 

49 path = os.path.join(tmp, "x.fits") 

50 _write_simple_image_fits(path) 

51 with FitsInputArchive.open(path): 

52 pass 

53 

54 def test_read_fails_when_fmtver_too_high(self): 

55 """A file whose FMTVER is newer than this release raises.""" 

56 with tempfile.TemporaryDirectory() as tmp: 

57 path = os.path.join(tmp, "x.fits") 

58 _write_simple_image_fits(path) 

59 with astropy.io.fits.open(path, mode="update") as hdul: 

60 hdul[0].header["FMTVER"] = 2 

61 hdul.flush() 

62 with self.assertRaises(ArchiveReadError): 

63 with FitsInputArchive.open(path): 

64 pass 

65 

66 def test_read_succeeds_when_fmtver_absent(self): 

67 """A legacy file lacking FMTVER reads successfully (defaults to 1).""" 

68 with tempfile.TemporaryDirectory() as tmp: 

69 path = os.path.join(tmp, "x.fits") 

70 _write_simple_image_fits(path) 

71 with astropy.io.fits.open(path, mode="update") as hdul: 

72 if "FMTVER" in hdul[0].header: 

73 del hdul[0].header["FMTVER"] 

74 if "DATAMODL" in hdul[0].header: 

75 del hdul[0].header["DATAMODL"] 

76 hdul.flush() 

77 with FitsInputArchive.open(path): 

78 pass 

79 

80 

81if __name__ == "__main__": 

82 unittest.main()