Copy whitespace from original file to preserve spaces vs tabs

Author: ntninja

src/unasync/__init__.py

@@ -149,7 +149,7 @@ def _tokenize(f):
         space = ""
         if tok.start > last_end:
             assert tok.start[0] == last_end[0]
-            space = " " * (tok.start[1] - last_end[1])
+            space = tok.line[last_end[1] : tok.start[1]]
         yield (space, tok.type, tok.string)
 
         last_end = tok.end

tests/data/async/tabs.py

@@ -0,0 +1,8 @@
+# fmt: off
+async def dummy():
+	await dummy2()  # This line is indented with a tab that should be preserved
+# fmt: on
+
+
+async def dummy2():
+    await dummy()  # This one uses 4 spaces and these should also be preserved

tests/data/sync/tabs.py

@@ -0,0 +1,8 @@
+# fmt: off
+def dummy():
+	dummy2()  # This line is indented with a tab that should be preserved
+# fmt: on
+
+
+def dummy2():
+    dummy()  # This one uses 4 spaces and these should also be preserved