1 files changed, 77 insertions, 0 deletions
diff --git a/test/reader/preview/test_preview.py b/test/reader/preview/test_preview.py
new file mode 100644
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+++ b/test/reader/preview/test_preview.py
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+"""
+
+Part of the bsie test suite.
+A copy of the license is provided with the project.
+Author: Matthias Baumgartner, 2022
+"""
+# standard imports
+from functools import partial
+import importlib
+import os
+import unittest
+
+# external imports
+import PIL.Image
+
+# bsie imports
+from bsie.utils import errors
+
+# objects to test
+from bsie.reader.preview import Preview
+
+
+## code ##
+
+class TestPreview(unittest.TestCase):
+    def setUp(self):
+        if __package__ is None or __package__ == '': # direct call or local discovery
+            importlib.import_module('load_nef', __package__).get()
+        else: # parent discovery
+            importlib.import_module('.load_nef', __package__).get()
+
+    def test_construct(self):
+        preview = Preview()
+        self.assertIsInstance(preview, Preview)
+        self.assertEqual(len(preview._children), 3)
+
+    def test_call(self):
+        preview = Preview()
+        # call raises error if file cannot be read
+        self.assertRaises(errors.ReaderError, preview,
+            os.path.join(os.path.dirname(__file__), 'missing.jpg'))
+        self.assertRaises(errors.ReaderError, preview(
+            os.path.join(os.path.dirname(__file__), 'invalid.jpg')), 10)
+        self.assertRaises(errors.UnsupportedFileFormatError, preview,
+            os.path.join(os.path.dirname(__file__), 'invalid.foo'))
+
+        # call returns raw preview
+        gen = preview(os.path.join(os.path.dirname(__file__), 'testimage.nef'))
+        img = gen(10)
+        self.assertIsInstance(img, PIL.Image.Image)
+        self.assertEqual(img.size, (10, 8))
+        self.assertEqual(sum(band for pix in img.getdata() for band in pix), 25287)
+        img.close()
+
+        # call returns jpeg image
+        gen = preview(os.path.join(os.path.dirname(__file__), 'testimage.jpg'))
+        img = gen(10)
+        self.assertIsInstance(img, PIL.Image.Image)
+        self.assertEqual(img.size, (10, 10))
+        self.assertEqual(sum(band for pix in img.getdata() for band in pix), 0)
+        img.close()
+
+        # preview generator can also extract data from non-image files
+        gen = preview(os.path.join(os.path.dirname(__file__), 'testfile.pdf'))
+        img = gen(10)
+        self.assertIsInstance(img, PIL.Image.Image)
+        self.assertEqual(img.size, (8, 10))
+        self.assertEqual(sum(img.getdata()), 20258)
+        img.close()
+
+
+## main ##
+
+if __name__ == '__main__':
+    unittest.main()
+
+## EOF ##