Overview Description

A custom bear and providing your own process_output does not result in the correct file parameter, when the file in question does not end in a newline; the newline is added by the linter class.

This is problematic for a bear that adds a newline at the end of a file.

Steps to Reproduce

1. Create a bear that prints the provided file contents and also the actual file contents

from coalib.bearlib.abstractions.Linter import linter

@linter(executable='echo', # we use echo to print some random output to force usage of process_output
        output_format=None
        )

class TestBear:
    @staticmethod
    def create_arguments(filename, file, config_file):
        return ["asd"]

    def process_output(self, output, filename=None, file=None):
        contents = ""
        with open(filename) as f:
            for line in f.readlines():
                contents += line
        print("---------")
        print(repr(contents))
        print("---------")
        print(file)            
        print("---------")

2. Create a file that ends without newline
   printf asd > test.txt

3. Run the bear and compare

coala -b TestBear -d . -f ./test.txt -I

Actual Results

Executing section cli...
---------
'asd'
---------
('asd\n',)
---------

As you you can see there is an additional newline.

Expected Results

Executing section cli...
---------
'asd'
---------
('asd',)
---------

Reproducibility

Every time

Additional Information:

Actually having the newline in the file results in the output:

Executing section cli...
---------
'asd\n'
---------
('asd\n',)
---------

The newline seems to only be added if there is none present.