Added: End of line detection and configuration.

.gitignore

@@ -44,6 +44,7 @@ nosetests.xml
 coverage.xml
 *,cover
 .hypothesis/
+.pytest_cache
 
 # Translations
 *.mo

cookiecutter/generate.py

@@ -170,9 +170,15 @@ def generate_file(project_dir, infile, context, env, skip_if_file_exists=False):
             raise
         rendered_file = tmpl.render(**context)
 
+        # Detect original file newline to output the rendered file
+        # note: newline='' ensures newlines are not converted
+        with io.open(infile, 'r', encoding='utf-8', newline='') as rd:
+            rd.readline()  # Read the first line to load 'newlines' value
+            newline = getattr(rd, 'newlines')
+
         logger.debug('Writing contents to file %s', outfile)
 
-        with io.open(outfile, 'w', encoding='utf-8') as fh:
+        with io.open(outfile, 'w', encoding='utf-8', newline=newline) as fh:
             fh.write(rendered_file)
 
     # Apply file permissions to output file

tests/files/{{generate_file}}_crlf_newlines.txt

@@ -0,0 +1,5 @@
+newline is CRLF
+newline is CRLF
+newline is CRLF
+
+

tests/files/{{generate_file}}_lf_newlines.txt

@@ -0,0 +1,3 @@
+newline is LF
+newline is LF
+

tests/test-generate-files-line-end/cookiecutter.json

@@ -0,0 +1,9 @@
+{
+    "full_name": "Philippe Ombredanne",
+    "year": "2015",
+    "color": "blue",
+    "letter": "D",
+    "folder_name": "im_a.dir",
+    "filename": "im_a.file",
+    "test_name": "output_folder"
+}

tests/test-generate-files-line-end/{{cookiecutter.test_name}}/folder/in_folder.txt

@@ -0,0 +1 @@
+The color is {{ cookiecutter.color }} and the letter is {{ cookiecutter.letter }}.

tests/test-generate-files-line-end/{{cookiecutter.test_name}}/something.txt

@@ -0,0 +1,3 @@
+Hi!
+My name is {{ cookiecutter.full_name }}.
+It is {{ cookiecutter.year }}.

tests/test-generate-files-line-end/{{cookiecutter.test_name}}/{{cookiecutter.folder_name}}/{{cookiecutter.filename}}.py

@@ -0,0 +1 @@
+print("This is the contents of {{ cookiecutter.filename }}.py.")

tests/test-generate-files/input{{cookiecutter.food}}/simple-with-newline-crlf.txt

@@ -0,0 +1 @@
+I eat {{ cookiecutter.food }}

tests/test_generate_file.py

@@ -20,6 +20,10 @@ def tear_down():
     yield
     if os.path.exists('tests/files/cheese.txt'):
         os.remove('tests/files/cheese.txt')
+    if os.path.exists('tests/files/cheese_lf_newlines.txt'):
+        os.remove('tests/files/cheese_lf_newlines.txt')
+    if os.path.exists('tests/files/cheese_crlf_newlines.txt'):
+        os.remove('tests/files/cheese_crlf_newlines.txt')
 
 
 @pytest.fixture
@@ -117,3 +121,34 @@ def test_generate_file_verbose_template_syntax_error(env, expected_msg):
             env=env,
         )
     assert str(exception.value) == expected_msg
+
+
+def test_generate_file_does_not_translate_lf_newlines_to_crlf(env):
+    """Verify that file generation use same line ending, as in source file."""
+    infile = 'tests/files/{{generate_file}}_lf_newlines.txt'
+    generate.generate_file(
+        project_dir=".", infile=infile, context={'generate_file': 'cheese'}, env=env
+    )
+    # this generated file should not have a CRLF line ending
+    gf = 'tests/files/cheese_lf_newlines.txt'
+    for line in open(gf):
+        msg = 'Missing LF line ending for generated file: {gf}'
+        assert line.endswith('\n'), msg.format(**locals())
+        msg = 'Incorrect CRLF line ending for generated file: {gf}'
+        assert not line.endswith('\r\n'), msg.format(**locals())
+
+
+def test_generate_file_does_translate_crlf_newlines_to_lf(env):
+    """Verify that file generation use same line ending, as in source file."""
+    infile = 'tests/files/{{generate_file}}_crlf_newlines.txt'
+    generate.generate_file(
+        project_dir=".", infile=infile, context={'generate_file': 'cheese'}, env=env
+    )
+
+    # this generated file should not have a CRLF line ending
+    gf = 'tests/files/cheese_crlf_newlines.txt'
+    for line in open(gf):
+        msg = 'Missing LF line ending for generated file: {gf}'
+        assert line.endswith('\n'), msg.format(**locals())
+        msg = 'Incorrect CRLF line ending for generated file: {gf}'
+        assert not line.endswith('\r\n'), msg.format(**locals())

tests/test_generate_files.py

@@ -39,6 +39,8 @@ def remove_additional_folders():
         utils.rmtree('tests/custom_output_dir')
     if os.path.exists('inputpermissions'):
         utils.rmtree('inputpermissions')
+    if os.path.exists('tests/line-end-output'):
+        utils.rmtree('tests/line-end-output')
 
 
 @pytest.mark.usefixtures('clean_system', 'remove_additional_folders')
@@ -84,6 +86,25 @@ def test_generate_files_with_trailing_newline():
     with io.open(newline_file, 'r', encoding='utf-8') as f:
         simple_text = f.read()
     assert simple_text == 'I eat pizzä\n'
+    assert f.newlines == '\n'
+
+
+@pytest.mark.usefixtures('clean_system', 'remove_additional_folders')
+def test_generate_files_with_windows_newline():
+    generate.generate_files(
+        context={
+            'cookiecutter': {'food': 'pizzä'}
+        },
+        repo_dir='tests/test-generate-files'
+    )
+
+    newline_file = 'inputpizzä/simple-with-newline-crlf.txt'
+    assert os.path.isfile(newline_file)
+
+    with io.open(newline_file, 'r') as f:
+        f.read()
+
+    assert f.newlines == '\r\n'
 
 
 @pytest.mark.usefixtures('clean_system', 'remove_additional_folders')
@@ -171,6 +192,34 @@ def test_generate_files_permissions():
     assert tests_script_file_mode == input_script_file_mode
 
 
+@pytest.mark.usefixtures('clean_system', 'remove_additional_folders')
+def test_generate_files_does_not_change_line_endings():
+    """Verify that template generation use same line ending, as in source file."""
+    context = generate.generate_context(
+        context_file='tests/test-generate-files-line-end/cookiecutter.json'
+    )
+
+    generate.generate_files(
+        context=context,
+        repo_dir='tests/test-generate-files-line-end',
+        output_dir='tests/line-end-output',
+    )
+
+    generated_files = [
+        'tests/line-end-output/output_folder/something.txt',
+        'tests/line-end-output/output_folder/folder/in_folder.txt',
+        'tests/line-end-output/output_folder/im_a.dir/im_a.file.py',
+    ]
+
+    # these generated files should not have a CRLF line ending
+    for gf in generated_files:
+        for line in open(gf):
+            msg = 'Missing LF line ending for generated file: {gf}'
+            assert line.endswith('\n'), msg.format(**locals())
+            msg = 'Incorrect CRLF line ending for generated file: {gf}'
+            assert not line.endswith('\r\n'), msg.format(**locals())
+
+
 @pytest.mark.usefixtures('clean_system', 'remove_additional_folders')
 def test_generate_files_with_overwrite_if_exists_with_skip_if_file_exists():
     """Verify `skip_if_file_exist` has priority over `overwrite_if_exists`."""