Return continuation even if no chat data

pytchat/tool/download/asyncdl.py

@@ -1,4 +1,3 @@
-
 import aiohttp
 import asyncio
 import json
@@ -105,7 +104,7 @@ def download_patch(callback, blocks, video_id):
             if callback:
                 callback(actions, last - first)
             return Patch(actions, continuation, first, last)
-        return Patch()
+        return Patch(continuation = continuation)
     """
     allocate workers and assign blocks.
     """   

pytchat/tool/download/patch.py

@@ -22,7 +22,6 @@ def fill(block:Block, patch:Patch):
         if line_offset < block_end:
             break
         patch.chats.pop()
-        
     set_patch(block, patch._replace(
         continuation = None,
         last = line_offset
@@ -34,8 +33,9 @@ def fill(block:Block, patch:Patch):
 
 def split(parent_block:Block, child_block:Block, patch:Patch):
     parent_block.during_split = False
-    """patch overlaps with parent_block"""
     if patch.first <= parent_block.last:
+        ''' When patch overlaps with parent_block,
+        discard this block. '''
         child_block.continuation = None
         ''' Leave child_block.during_split == True 
          to exclude from during_split sequence. '''

tests/test_dl_duplcheck.py

@@ -66,7 +66,7 @@ def test_duplicate_head():
                     [4] , [5]  -> append  [4]
                     append [5]
 
-        result    : [0] , [3] , [5] 
+        result    : [2] , [4] , [5] 
     """
 
     #chat data offsets are ignored.

tests/test_patch.py

@@ -23,6 +23,8 @@ def test_split_0():
     """
     Normal case
 
+    ~~~~~~ before ~~~~~~
+
      @parent_block  (# = already downloaded)
     
      first    last                                     end
@@ -31,8 +33,8 @@ def test_split_0():
 
      @child_block
     
-     first = last = 0                                  end=parent_end
-     ---------------------------------------------------|
+     first = last = 0                                  end (=parent_end)
+       |                                                |
     
 
      @fetched patch
@@ -43,6 +45,9 @@ def test_split_0():
                             |
                             V 
 
+    ~~~~~~ after ~~~~~~
+    
+
      @parent_block
     
      first    last         end (after split)   
@@ -87,8 +92,8 @@ def test_split_1():
        |####################|#####|---------------------|
                             ^
      @child_block
-     first = last = 0                                  end=parent_end
-     ---------------------------------------------------|
+     first = last = 0                                  end (=parent_end)
+       |                                                |
      
      @fetched patch
                             |-- patch --|
@@ -135,8 +140,8 @@ def test_split_2():
        |########------------------------------|
     
      @child_block
-     first = last = 0                        end=parent_end
-     -----------------------------------------|
+     first = last = 0                        end (=parent_end)
+       |                                      |
     
     continuation:succeed from patch
     
@@ -196,8 +201,8 @@ def test_split_none():
        |####################|###################|-------|
                             ^
      @child_block
-     first = last = 0                                  end=parent_end
-     ---------------------------------------------------|
+     first = last = 0                                  end (=parent_end)
+       |                                                |
      
      @fetched patch
                             |-- patch --|
@@ -212,7 +217,7 @@ def test_split_none():
      @parent_block
      first                       last           end (before split)
        |########################################|-------|
-                                                              .
+
      @child_block
                                            
                             ............    -> discard all data.