modded combox.file.hash_file function -- added new arg `file_content'

   - `file_content' is set to None by default
   - If `file_content' is not None, hash of this is returned.

Updated the test for hash_file function.

	modified:   combox/file.py
	modified:   tests/file_test.py

2 files changed, 9 insertions, 4 deletions

diff --git a/combox/file.py b/combox/file.py
index 959954a..d7602e9 100644
--- a/combox/file.py
+++ b/combox/file.py
@@ -301,14 +301,17 @@ def read_file(filename):
     return file_.read()
 
 
-def hash_file(filename):
+def hash_file(filename, file_content=None):
     """Does a SHA512 hash on the contents of file.
 
     Returns the hexdigest of the file content's hash.
 
     filename: Absolute pathname of the file.
+    file_content: If not None, hash of file_content is returned.
     """
-    file_content = read_file(filename)
+
+    if not file_content:
+        file_content = read_file(filename)
 
     return sha512(file_content).hexdigest()
 
diff --git a/tests/file_test.py b/tests/file_test.py
index 807ed23..7c041b7 100644
--- a/tests/file_test.py
+++ b/tests/file_test.py
@@ -88,10 +88,12 @@ class TestFile(object):
         """
         Tests the hashing function - hash_file
         """
-        fhash = hash_file(self.TEST_FILE)
         fcontent = read_file(self.TEST_FILE)
+        fhash_0 = hash_file(self.TEST_FILE)
+        fhash_1 = hash_file(self.TEST_FILE, fcontent)
 
-        assert fhash == sha512(fcontent).hexdigest()
+        assert fhash_0 == sha512(fcontent).hexdigest()
+        assert fhash_1 == sha512(fcontent).hexdigest()
 
 
     def test_relativepath(self):