Enable some test_struct tests (#953)

Author: slozier

Src/IronPythonTest/Cases/CPythonCasesManifest.ini

@@ -942,7 +942,7 @@ Ignore=true
 Ignore=true
 Reason=unittest.case.SkipTest: correctly-rounded string->float conversions not available on this system
 
-[CPython.test_struct]
+[CPython.test_struct] # IronPython.test_struct_stdlib
 Ignore=true
 
 [CPython.test_structmembers]

Src/StdLib/Lib/test/test_struct.py

@@ -591,7 +591,6 @@ def test__sizeof__(self):
         self.check_sizeof('0c', 0)
 
 
-@unittest.skipIf(sys.implementation.name == "ironpython", "not implemented")
 class UnpackIteratorTest(unittest.TestCase):
     """
     Tests for iterative unpacking (struct.Struct.iter_unpack).

Tests/test_struct_stdlib.py

@@ -0,0 +1,48 @@
+# Licensed to the .NET Foundation under one or more agreements.
+# The .NET Foundation licenses this file to you under the Apache 2.0 License.
+# See the LICENSE file in the project root for more information.
+
+##
+## Run selected tests from test_struct from StdLib
+##
+
+import unittest
+import sys
+
+from iptest import run_test
+
+import test.test_struct
+
+def load_tests(loader, standard_tests, pattern):
+    if sys.implementation.name == 'ironpython':
+        suite = unittest.TestSuite()
+        #suite.addTest(test.test_struct.StructTest('test_1530559'))
+        #suite.addTest(test.test_struct.StructTest('test_705836'))
+        suite.addTest(test.test_struct.StructTest('test_Struct_reinitialization'))
+        suite.addTest(test.test_struct.StructTest('test__sizeof__'))
+        #suite.addTest(test.test_struct.StructTest('test_bool'))
+        #suite.addTest(test.test_struct.StructTest('test_calcsize'))
+        suite.addTest(test.test_struct.StructTest('test_consistence'))
+        #suite.addTest(test.test_struct.StructTest('test_count_overflow'))
+        #suite.addTest(test.test_struct.StructTest('test_integers'))
+        suite.addTest(test.test_struct.StructTest('test_isbigendian'))
+        suite.addTest(test.test_struct.StructTest('test_nN_code'))
+        suite.addTest(test.test_struct.StructTest('test_new_features'))
+        suite.addTest(test.test_struct.StructTest('test_p_code'))
+        suite.addTest(test.test_struct.StructTest('test_pack_into'))
+        suite.addTest(test.test_struct.StructTest('test_pack_into_fn'))
+        #suite.addTest(test.test_struct.StructTest('test_trailing_counter'))
+        suite.addTest(test.test_struct.StructTest('test_transitiveness'))
+        suite.addTest(test.test_struct.StructTest('test_unpack_from'))
+        suite.addTest(test.test_struct.StructTest('test_unpack_with_buffer'))
+        suite.addTest(test.test_struct.UnpackIteratorTest('test_arbitrary_buffer'))
+        #suite.addTest(test.test_struct.UnpackIteratorTest('test_construct'))
+        suite.addTest(test.test_struct.UnpackIteratorTest('test_iterate'))
+        suite.addTest(test.test_struct.UnpackIteratorTest('test_length_hint'))
+        suite.addTest(test.test_struct.UnpackIteratorTest('test_module_func'))
+        return suite
+
+    else:
+        return loader.loadTestsFromModule(test.test_struct, pattern)
+
+run_test(__name__)