Add a test for PNG files

src/parsers/png.py

@@ -7,12 +7,21 @@ from . import abstract
 
 class PNGParser(abstract.AbstractParser):
     mimetypes = {'image/png', }
-    meta_list = set()
+    meta_whitelist = {'SourceFile', 'ExifToolVersion', 'FileName',
+            'Directory', 'FileSize', 'FileModifyDate', 'FileAccessDate',
+            "FileInodeChangeDate", 'FilePermissions', 'FileType',
+            'FileTypeExtension', 'MIMEType', 'ImageWidth', 'BitDepth', 'ColorType',
+            'Compression', 'Filter', 'Interlace', 'BackgroundColor', 'ImageSize',
+            'Megapixels', 'ImageHeight'}
 
     def get_meta(self):
         out = subprocess.check_output(['exiftool', '-json', self.filename])
-        return json.loads(out)[0]
+        meta = json.loads(out)[0]
+        for key in self.meta_whitelist:
+            meta.pop(key, None)
+        return meta
 
     def remove_all(self):
         surface = cairo.ImageSurface.create_from_png(self.filename)
         surface.write_to_png(self.output_filename)
+        return True

tests/test_libmat2.py

@@ -5,7 +5,7 @@ import shutil
 import os
 
 from src import parsers
-from src.parsers import pdf
+from src.parsers import pdf, png
 
 class TestGetMeta(unittest.TestCase):
     def test_pdf(self):
@@ -14,14 +14,15 @@ class TestGetMeta(unittest.TestCase):
         self.assertEqual(meta['producer'], 'pdfTeX-1.40.14')
         self.assertEqual(meta['creator'], "'Certified by IEEE PDFeXpress at 03/19/2016 2:56:07 AM'")
 
+    def test_png(self):
+        p = png.PNGParser('./tests/data/dirty.png')
+        meta = p.get_meta()
+        self.assertEqual(meta['Comment'], 'This is a comment, be careful!')
+        self.assertEqual(meta['ModifyDate'], "2018:03:20 21:59:25")
+
 class TestCleaning(unittest.TestCase):
-    def setUp(self):
-        shutil.copy('./tests/data/dirty.pdf', './tests/data/clean.pdf')
-
-    def tearDown(self):
-        os.remove('./tests/data/clean.pdf')
-
     def test_pdf(self):
+        shutil.copy('./tests/data/dirty.pdf', './tests/data/clean.pdf')
         p = pdf.PDFParser('./tests/data/clean.pdf')
 
         meta = p.get_meta()
@@ -33,3 +34,20 @@ class TestCleaning(unittest.TestCase):
         p = pdf.PDFParser('./tests/data/clean.pdf.cleaned')
         expected_meta = {'creation-date': -1, 'format': 'PDF-1.5', 'mod-date': -1}
         self.assertEqual(p.get_meta(), expected_meta)
+
+        os.remove('./tests/data/clean.pdf')
+
+    def test_png(self):
+        shutil.copy('./tests/data/dirty.png', './tests/data/clean.png')
+        p = png.PNGParser('./tests/data/clean.png')
+
+        meta = p.get_meta()
+        self.assertEqual(meta['Comment'], 'This is a comment, be careful!')
+
+        ret = p.remove_all()
+        self.assertTrue(ret)
+
+        p = png.PNGParser('./tests/data/clean.png.cleaned')
+        self.assertEqual(p.get_meta(), {})
+
+        os.remove('./tests/data/clean.png')