2 files changed, 128 insertions, 0 deletions
diff --git a/test/extractor/test_preview.py b/test/extractor/test_preview.py
new file mode 100644
index 0000000..10d2a7f
--- /dev/null
+++ b/test/extractor/test_preview.py
@@ -0,0 +1,128 @@
+"""
+
+Part of the bsie test suite.
+A copy of the license is provided with the project.
+Author: Matthias Baumgartner, 2022
+"""
+# standard imports
+import io
+import os
+import unittest
+
+# external imports
+import PIL.Image
+
+# bsie imports
+from bsie.extractor import base
+from bsie.utils import bsfs, node as _node, ns
+from bsie.reader.preview import Preview as Reader
+
+# objects to test
+from bsie.extractor.preview import Preview
+
+
+## code ##
+
+class TestPreview(unittest.TestCase):
+    def test_eq(self):
+        # identical instances are equal
+        self.assertEqual(Preview([1,2,3]), Preview([1,2,3]))
+        self.assertEqual(hash(Preview([1,2,3])), hash(Preview([1,2,3])))
+        # comparison respects max_sides
+        self.assertNotEqual(Preview([1,2,3]), Preview([1,2]))
+        self.assertNotEqual(hash(Preview([1,2,3])), hash(Preview([1,2])))
+        self.assertNotEqual(Preview([1,2]), Preview([1,2,3]))
+        self.assertNotEqual(hash(Preview([1,2])), hash(Preview([1,2,3])))
+        # comparison respects type
+        class Foo(): pass
+        self.assertNotEqual(Preview([1,2,3]), Foo())
+        self.assertNotEqual(hash(Preview([1,2,3])), hash(Foo()))
+        self.assertNotEqual(Preview([1,2,3]), 123)
+        self.assertNotEqual(hash(Preview([1,2,3])), hash(123))
+        self.assertNotEqual(Preview([1,2,3]), None)
+        self.assertNotEqual(hash(Preview([1,2,3])), hash(None))
+
+    def test_schema(self):
+        self.assertEqual(Preview([1,2,3]).schema,
+            bsfs.schema.from_string(base.SCHEMA_PREAMBLE + '''
+                bsfs:Preview rdfs:subClassOf bsfs:Node .
+                bsfs:BinaryBlob rdfs:subClassOf bsfs:Literal .
+                bsfs:JPEG rdfs:subClassOf bsfs:BinaryBlob .
+
+                bse:preview rdfs:subClassOf bsfs:Predicate ;
+                    rdfs:domain bsfs:File ;
+                    rdfs:range bsfs:Preview ;
+                    bsfs:unique "false"^^xsd:boolean .
+
+                bsp:width rdfs:subClassOf bsfs:Predicate ;
+                    rdfs:domain bsfs:Preview ;
+                    rdfs:range xsd:integer ;
+                    bsfs:unique "true"^^xsd:boolean .
+
+                bsp:height rdfs:subClassOf bsfs:Predicate ;
+                    rdfs:domain bsfs:Preview ;
+                    rdfs:range xsd:integer ;
+                    bsfs:unique "true"^^xsd:boolean .
+
+                bsp:asset rdfs:subClassOf bsfs:Predicate ;
+                    rdfs:domain bsfs:Preview ;
+                    rdfs:range bsfs:JPEG ;
+                    bsfs:unique "true"^^xsd:boolean .
+
+                '''))
+
+    def test_extract(self):
+        # setup dependents
+        rdr = Reader()
+        subject = _node.Node(ns.bsfs.File)
+        path = os.path.join(os.path.dirname(__file__), 'testimage.jpg')
+
+        # setup extractor
+        ext = Preview(max_sides=[10])
+        principals = set(ext.principals)
+        self.assertEqual(principals, {ext.schema.predicate(ns.bse.preview)})
+        # skip unknown predicates
+        gen = rdr(path)
+        self.assertSetEqual(set(), set(ext.extract(subject, gen,
+            {ext.schema.predicate(ns.bsfs.Predicate).child(ns.bse.unknown)})))
+        gen(10) # NOTE: consume some image to avoid resource error warning
+        # extract a preview
+        triples = set(ext.extract(subject, rdr(path), principals))
+        thumbs = {node for node, _, _ in triples if node.node_type == ns.bsfs.Preview}
+        self.assertEqual(len(thumbs), 1)
+        thumb = list(thumbs)[0]
+        # test properties
+        self.assertTrue(triples.issuperset({
+            (subject, ext.schema.predicate(ns.bse.preview), thumb),
+            (thumb, ext.schema.predicate(ns.bsp.width), 10),
+            (thumb, ext.schema.predicate(ns.bsp.height), 10),
+            }))
+        # test image data
+        rawdata = {val for _, pred, val in triples if pred == ext.schema.predicate(ns.bsp.asset)}
+        self.assertEqual(len(rawdata), 1)
+        data = io.BytesIO(list(rawdata)[0])
+        data.seek(0)
+        img = PIL.Image.open(data)
+        self.assertEqual(img.size, (10, 10))
+        self.assertEqual(sum(band for pix in img.getdata() for band in pix), 0)
+
+        # setup extractor
+        ext = Preview(max_sides=[10, 20])
+        principals = set(ext.principals)
+        self.assertEqual(principals, {ext.schema.predicate(ns.bse.preview)})
+        # extract a preview
+        triples = set(ext.extract(subject, rdr(path), principals))
+        thumbs = {node for node, _, _ in triples if node.node_type == ns.bsfs.Preview}
+        self.assertEqual(len(thumbs), 2)
+        self.assertSetEqual({10, 20}, {
+            value for _, pred, value in triples if pred == ext.schema.predicate(ns.bsp.width)})
+        self.assertSetEqual({10, 20}, {
+            value for _, pred, value in triples if pred == ext.schema.predicate(ns.bsp.height)})
+
+
+## main ##
+
+if __name__ == '__main__':
+    unittest.main()
+
+## EOF ##
diff --git a/test/extractor/testimage.jpg b/test/extractor/testimage.jpg
new file mode 100644
index 0000000..4c2aca5
--- /dev/null
+++ b/test/extractor/testimage.jpg