Added feedback

Author: sumezulike

src/black/ranges.py

@@ -58,7 +58,9 @@ def sanitized_lines(
     if not src_contents:
         return []
     good_lines = []
-    src_line_count = len(src_contents.splitlines())
+    src_line_count = src_contents.count("\n")
+    if not src_contents.endswith("\n"):
+        src_line_count += 1
     for start, end in lines:
         if start > src_line_count:
             continue

tests/data/cases/line_ranges_outside_source.py

@@ -5,37 +5,3 @@ def foo1(parameter_1, parameter_2, parameter_3, parameter_4, parameter_5, parame
 def foo2(parameter_1, parameter_2, parameter_3, parameter_4, parameter_5, parameter_6, parameter_7): pass
 def foo3(parameter_1, parameter_2, parameter_3, parameter_4, parameter_5, parameter_6, parameter_7): pass
 def foo4(parameter_1, parameter_2, parameter_3, parameter_4, parameter_5, parameter_6, parameter_7): pass
-
-# Adding some unformated code covering a wide range of syntaxes.
-
-if True:
-      # Incorrectly indented prefix comments.
-  pass
-
-import   typing
-from  typing   import   (
-      Any  ,
-   )
-class   MyClass(  object):     # Trailing comment with extra leading space.
-        #NOTE: The following indentation is incorrect:
-      @decor( 1  *  3 )
-      def  my_func(  arg):
-                pass
-
-try:                                       # Trailing comment with extra leading space.
-    for   i   in   range(10):              # Trailing comment with extra leading space.
-        while    condition:
-            if   something:
-                then_something(  )
-            elif    something_else:
-                then_something_else(  )
-except  ValueError  as  e:
-    unformatted(  )
-finally:
-    unformatted(  )
-
-async  def  test_async_unformatted(  ):    # Trailing comment with extra leading space.
-    async  for  i  in some_iter(  unformatted  ):    # Trailing comment with extra leading space.
-        await  asyncio.sleep( 1 )
-        async  with  some_context(  unformatted  ):
-            print(  "unformatted"  )

tests/test_ranges.py

@@ -240,3 +240,10 @@ def test_sanitize(
 4.   pass
 """
     assert sanitized == sanitized_lines(lines, source)
+
+    source_no_trailing_nl = """\
+    1. import re
+    2. def func(arg1,
+    3.   arg2, arg3):
+    4.   pass"""
+    assert sanitized == sanitized_lines(lines, source_no_trailing_nl)