serve-robotics
diff --git a/‎tools/par_test.py
Copy file name to clipboardExpand all lines: tools/par_test.py
+65-17 b/‎tools/par_test.py
Copy file name to clipboardExpand all lines: tools/par_test.py
+65-17
@@ -12,34 +12,82 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import difflib
 import hashlib
 import os
 import unittest
+import zipfile
 
 
 def TestData(name):
   return os.path.join(os.environ['TEST_SRCDIR'], 'io_bazel_rules_python', name)
 
 
+def _format_toc(filename):
+    """Return a table of contents for the zip file as a string.
+
+    Args:
+        filename (str): Path to zip file
+
+    Returns: directory listed in format matching zipfile.printdir()
+    """
+    zf = zipfile.ZipFile(filename)
+    lines = []
+    lines.append("%-46s %19s %12s" % ("File Name", "Modified    ", "Size"))
+    for zinfo in zf.filelist:
+        date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
+        lines.append("%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size))
+    return lines
+
+
 class WheelTest(unittest.TestCase):
 
-  def test_piptool_matches(self):
-    with open(TestData('rules_python/piptool.par'), 'r') as f:
-      built = f.read()
-    with open(TestData('tools/piptool.par'), 'r') as f:
-      checked_in = f.read()
-    self.assertEquals(
-      hashlib.sha256(built).hexdigest(), hashlib.sha256(checked_in).hexdigest(),
-      'The checked in tools/piptool.par does not match the latest build.')
-
-  def test_whltool_matches(self):
-    with open(TestData('rules_python/whltool.par'), 'r') as f:
-      built = f.read()
-    with open(TestData('tools/whltool.par'), 'r') as f:
-      checked_in = f.read()
-    self.assertEquals(
-      hashlib.sha256(built).hexdigest(), hashlib.sha256(checked_in).hexdigest(),
-      'The checked in tools/whltool.par does not match the latest build.')
+    def _diff_zip(self, filename1, filename2):
+        """Compare two zip files for equality, pretty-printing differences."""
+        with open(filename1, 'rb') as file1:
+            contents1 = file1.read()
+        with open (filename2, 'rb') as file2:
+            contents2 = file2.read()
+        if contents1 != contents2:
+            toc1 = _format_toc(filename1)
+            toc2 = _format_toc(filename2)
+            sha1 = hashlib.sha256(filename1).hexdigest()
+            sha2 = hashlib.sha256(filename2).hexdigest()
+            diff = difflib.unified_diff(toc1, toc2)
+            diff_str = '\n'.join(diff) or (
+                'No differences in zip contents, only in zip headers [not shown]')
+            message = r'''Files do not match.
+
+************************************************************************
+File 1: %s
+Length in bytes: %s
+SHA256: %s
+************************************************************************
+File 2: %s
+Length in Bytes: %s
+SHA256: %s
+************************************************************************
+Zip Content Diff:
+%s
+************************************************************************
+''' % (
+    filename1,
+    len(contents1),
+    sha1,
+    filename2,
+    len(contents2),
+    sha2,
+    diff_str,
+)
+            self.assertEquals(contents1, contents2, message)
+
+    def test_piptool_matches(self):
+        self._diff_zip(TestData('rules_python/piptool.par'),
+                       TestData('tools/piptool.par'))
+
+    def test_whltool_matches(self):
+        self._diff_zip(TestData('rules_python/whltool.par'),
+                       TestData('tools/whltool.par'))
 
 if __name__ == '__main__':
   unittest.main()