FileContains does not support binary files

[jelmer]

Migrated from Launchpad: https://bugs.launchpad.net/bugs/1250483

Original Reporter: Gavin Panella
Date Created: 2013-11-12 14:04:00.284077+00:00
Status on Launchpad: Triaged
Importance: Wishlist

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The code in FileContains.match():

       f = open(path)
       try:
           actual_contents = f.read()
           return self.matcher.match(actual_contents)
       finally:
           f.close()

opens a file in text mode on Python 3. From open()'s docstring:

 The default mode is 'rt' (open for reading text)
 ...
 Python distinguishes between files opened in binary and text modes,
 even when the underlying operating system doesn't. Files opened in
 binary mode (appending 'b' to the mode argument) return contents as
 bytes objects without any decoding. In text mode (the default, or when
 't' is appended to the mode argument), the contents of the file are
 returned as strings, the bytes having been first decoded using a
 platform-dependent encoding or using the specified encoding if given.

I think it would be kess surprising to open the file in binary mode.

An optional user-defined encoding might be useful too, if text is what
you need.