add testcase for padded dataset with decode op

tests/ut/python/dataset/test_paddeddataset.py

@@ -1,8 +1,12 @@
+from io import BytesIO
 import os
 import numpy as np
 import pytest
 import mindspore.dataset as ds
 from mindspore.mindrecord import FileWriter
+import mindspore.dataset.transforms.vision.c_transforms as V_C
+from PIL import Image
+
 FILES_NUM = 4
 CV_FILE_NAME = "../data/mindrecord/imagenet.mindrecord"
 CV_DIR_NAME = "../data/mindrecord/testImageNetData"
@@ -197,7 +201,7 @@ def test_raise_error():
         ds3.use_sampler(testsampler)
         assert excinfo.type == 'ValueError'
 
-def test_imagefolden_padded():
+def test_imagefolder_padded():
     DATA_DIR = "../data/dataset/testPK/data"
     data = ds.ImageFolderDatasetV2(DATA_DIR)
 
@@ -220,6 +224,32 @@ def test_imagefolden_padded():
     assert verify_list[8] == 1
     assert verify_list[9] == 6
 
+def test_imagefolder_padded_with_decode():
+    DATA_DIR = "../data/dataset/testPK/data"
+    data = ds.ImageFolderDatasetV2(DATA_DIR)
+
+    white_io = BytesIO()
+    Image.new('RGB', (224, 224), (255, 255, 255)).save(white_io, 'JPEG')
+    padded_sample = {}
+    padded_sample['image'] = np.array(bytearray(white_io), dtype='uint8')
+    padded_sample['label'] = np.array(-1, np.int32)
+
+    white_samples = [padded_sample, padded_sample, padded_sample, padded_sample]
+    data2 = ds.PaddedDataset(white_samples)
+    data3 = data + data2
+
+    num_shards = 5
+    count = 0
+    for shard_id in range(num_shards):
+        testsampler = ds.DistributedSampler(num_shards=num_shards, shard_id=shard_id, shuffle=False, num_samples=None)
+        data3.use_sampler(testsampler)
+        data3.map(input_columns="image", operations=V_C.Decode())
+        for ele in data3.create_dict_iterator():
+            print("label: {}".format(ele['label']))
+            count += 1
+    assert count == 48
+
+
 def test_more_shard_padded():
     result_list = []
     for i in range(8):