Fix NoneTypeError when requirements file is empty
diff --git a/pre_commit_hooks/requirements_txt_fixer.py b/pre_commit_hooks/requirements_txt_fixer.py
index efa1906..41e1ffc 100644
--- a/pre_commit_hooks/requirements_txt_fixer.py
+++ b/pre_commit_hooks/requirements_txt_fixer.py
@@ -30,21 +30,25 @@
def fix_requirements(f):
requirements = []
- before = []
+ before = list(f)
after = []
- for line in f:
- before.append(line)
+ before_string = b''.join(before)
- # If the most recent requirement object has a value, then it's time to
- # start building the next requirement object.
+ # If the file is empty (i.e. only whitespace/newlines) exit early
+ if before_string.strip() == b'':
+ return 0
+
+ for line in before:
+ # If the most recent requirement object has a value, then it's
+ # time to start building the next requirement object.
if not len(requirements) or requirements[-1].value is not None:
requirements.append(Requirement())
requirement = requirements[-1]
- # If we see a newline before any requirements, then this is a top of
- # file comment.
+ # If we see a newline before any requirements, then this is a
+ # top of file comment.
if len(requirements) == 1 and line.strip() == b'':
if len(requirement.comments) and requirement.comments[0].startswith(b'#'):
requirement.value = b'\n'
@@ -60,7 +64,6 @@
after.append(comment)
after.append(requirement.value)
- before_string = b''.join(before)
after_string = b''.join(after)
if before_string == after_string:
