Add line-endings argument to enforce specific newline format (fix Windows compatibility issues)

.pre-commit-config.yaml

@@ -53,7 +53,7 @@ repos:
             args: [-d, -i 4, -ci]
 
     - repo: https://github.com/PyCQA/bandit
-      rev: 1.7.5
+      rev: 1.8.6
       hooks:
           - id: bandit
 

ci/test

@@ -51,4 +51,30 @@ run pre_commit_hooks/yamlfmt.py --width 79 "${TMP_FILE}"
 run grep -v -q '.\{82\}' "${TMP_FILE}"
 run rm -f "${TMP_FILE}"
 
+# Test line endings
+# File command will say nothing about line terminators for LF, but will for CRLF and CR endings
+TMP_FILE="$(mktemp pre-commit-hook-yamlfmt-test.XXXXXXXXXXXXXXXXXXXX)"
+run cp -f ci/test-eolchars.txt "${TMP_FILE}"
+run pre_commit_hooks/yamlfmt.py --mapping 4 --sequence 6 --offset 4 --preserve-quotes "${TMP_FILE}"
+run grep -q -v "CRLF line terminators" <(file -b "${TMP_FILE}")
+run grep -q -v "CR line terminators" <(file -b "${TMP_FILE}")
+# No line-endings argument passed - should be LF only when run on *nix plaftorms
+run cp -f ci/test-eolchars.txt "${TMP_FILE}"
+run pre_commit_hooks/yamlfmt.py --mapping 4 --sequence 6 --offset 4 --preserve-quotes --line-endings lf "${TMP_FILE}"
+run grep -q -v 'CRLF line terminators' <(file -b "${TMP_FILE}")
+run grep -q -v 'CR line terminators' <(file -b "${TMP_FILE}")
+# LF line-endings argument passed - Should be not CR and not CRLF
+run cp -f ci/test-eolchars.txt "${TMP_FILE}"
+run pre_commit_hooks/yamlfmt.py --mapping 4 --sequence 6 --offset 4 --preserve-quotes --line-endings crlf "${TMP_FILE}"
+run grep -q 'CRLF line terminators' <(file -b "${TMP_FILE}")
+run grep -q -v 'CR line terminators' <(file -b "${TMP_FILE}")
+# CRLF argument passed - Should be CRLF line terminators
+run cp -f ci/test-eolchars.txt "${TMP_FILE}"
+run pre_commit_hooks/yamlfmt.py --mapping 4 --sequence 6 --offset 4 --preserve-quotes --line-endings cr "${TMP_FILE}"
+run grep -q -v 'CRLF line terminators' <(file -b "${TMP_FILE}")
+run grep -q 'CR line terminators' <(file -b "${TMP_FILE}")
+# CR argument passed - Should be CR line terminators
+# If the tests fail, the temp file is still there to inspect.
+run rm -f "${TMP_FILE}"
+
 run pre-commit run --all-files --hook-stage manual

ci/test-eolchars.txt

@@ -0,0 +1,5 @@
+---
+bar:
+    baz:
+        - blah
+        - phfft

pre_commit_hooks/yamlfmt.py

@@ -103,6 +103,13 @@ def __init__(self):
             action="store_true",
             help="whether to keep null values"
             )
+        parser.add_argument(
+            "--line-endings",
+            choices=['lf', 'crlf', 'cr'],
+            default="lf",
+            help="write output files with specific EOL (default EOL depends"
+                 " on OS)"
+            )
         parser.add_argument(
             "file_names",
             metavar="FILE_NAME",
@@ -139,6 +146,14 @@ def represent_none(self, _data):
                 return self.represent_scalar('tag:yaml.org,2002:null', 'null')
             yaml.representer.add_representer(type(None), represent_none)
 
+        line_endings_map = {
+            "lf": "\n",
+            "crlf": "\r\n",
+            "cr": "\r"
+        }
+        self.line_endings = line_endings_map.get(
+            kwargs.get("line_endings", None), None)
+
         self.yaml = yaml
         self.path = kwargs.get("path", None)
         self.content = list({})
@@ -167,7 +182,8 @@ def write_file(self, path=None):
         if not path:
             path = self.path
         try:
-            with open(path, "w", encoding='utf-8') as stream:
+            with open(path, "w", encoding='utf-8',
+                      newline=self.line_endings) as stream:
                 self.yaml.dump_all(self.content, stream)
         except IOError:
             self.fail(f"Unable to write {path}")
@@ -191,7 +207,8 @@ def main():
         preserve_quotes=args.preserve_quotes,
         preserve_null=args.preserve_null,
         explicit_start=args.explicit_start,
-        explicit_end=args.explicit_end
+        explicit_end=args.explicit_end,
+        line_endings=args.line_endings
         )
     for file_name in args.file_names:
         formatter.format(file_name)

setup.py

@@ -6,7 +6,7 @@
     name='yamlfmt',
     description='A pre-commit hook to format YAML files',
     url='https://github.com/jumanjihouse/pre-commit-hook-yamlfmt',
-    version='0.3.0',
+    version='0.4.0',
 
     install_requires=[
         'ruamel.yaml >=0.16.10, <=0.17.21',