Add option to force Unix EOL on YAML export via the CLI (#316)

* Initial stab at unix eol option to export functions
* Added test and linted
* Update pre-commit config
* Added more testing for coverage
* Lint fixes
* PR comments
* Fixed pre 3.10 type union
* export_test updates per PR

src/preset_cli/cli/superset/export.py

@@ -6,7 +6,7 @@
 import re
 from collections import defaultdict
 from pathlib import Path
-from typing import Any, Callable, List, Set, Tuple
+from typing import Any, Callable, List, Set, Tuple, Union
 from zipfile import ZipFile
 
 import click
@@ -21,6 +21,11 @@
 assert JINJA2_OPEN_MARKER != JINJA2_CLOSE_MARKER
 
 
+def get_newline_char(force_unix_eol: bool = False) -> Union[str, None]:
+    """Returns the newline character used by the open function"""
+    return "\n" if force_unix_eol else None
+
+
 @click.command()
 @click.argument("directory", type=click.Path(exists=True, resolve_path=True))
 @click.option(
@@ -35,6 +40,12 @@
     default=False,
     help="Disable Jinja template escaping",
 )
+@click.option(
+    "--force-unix-eol",
+    is_flag=True,
+    default=False,
+    help="Force Unix end-of-line characters, otherwise use system default",
+)
 @click.option(
     "--asset-type",
     help="Asset type",
@@ -71,6 +82,7 @@ def export_assets(  # pylint: disable=too-many-locals, too-many-arguments
     dashboard_ids: List[str],
     overwrite: bool = False,
     disable_jinja_escaping: bool = False,
+    force_unix_eol: bool = False,
 ) -> None:
     """
     Export DBs/datasets/charts/dashboards to a directory.
@@ -100,6 +112,7 @@ def export_assets(  # pylint: disable=too-many-locals, too-many-arguments
                 overwrite,
                 disable_jinja_escaping,
                 skip_related=not ids_requested,
+                force_unix_eol=force_unix_eol,
             )
 
 
@@ -111,6 +124,7 @@ def export_resource(  # pylint: disable=too-many-arguments, too-many-locals
     overwrite: bool,
     disable_jinja_escaping: bool,
     skip_related: bool = True,
+    force_unix_eol: bool = False,
 ) -> None:
     """
     Export a given resource and unzip it in a directory.
@@ -149,7 +163,8 @@ def export_resource(  # pylint: disable=too-many-arguments, too-many-locals
 
             file_contents = yaml.dump(asset_content, sort_keys=False)
 
-        with open(target, "w", encoding="utf-8") as output:
+        newline = get_newline_char(force_unix_eol)
+        with open(target, "w", encoding="utf-8", newline=newline) as output:
             output.write(file_contents)
 
 
@@ -221,8 +236,18 @@ def jinja_escaper(value: str) -> str:
     type=click.Path(resolve_path=True),
     default="users.yaml",
 )
+@click.option(
+    "--force-unix-eol",
+    is_flag=True,
+    default=False,
+    help="Force Unix end-of-line characters, otherwise use system default",
+)
 @click.pass_context
-def export_users(ctx: click.core.Context, path: str) -> None:
+def export_users(
+    ctx: click.core.Context,
+    path: str,
+    force_unix_eol: bool = False,
+) -> None:
     """
     Export users and their roles to a YAML file.
     """
@@ -234,7 +259,8 @@ def export_users(ctx: click.core.Context, path: str) -> None:
         {k: v for k, v in user.items() if k != "id"} for user in client.export_users()
     ]
 
-    with open(path, "w", encoding="utf-8") as output:
+    newline = get_newline_char(force_unix_eol)
+    with open(path, "w", encoding="utf-8", newline=newline) as output:
         yaml.dump(users, output)
 
 
@@ -244,16 +270,27 @@ def export_users(ctx: click.core.Context, path: str) -> None:
     type=click.Path(resolve_path=True),
     default="roles.yaml",
 )
+@click.option(
+    "--force-unix-eol",
+    is_flag=True,
+    default=False,
+    help="Force Unix end-of-line characters, otherwise use system default",
+)
 @click.pass_context
-def export_roles(ctx: click.core.Context, path: str) -> None:
+def export_roles(
+    ctx: click.core.Context,
+    path: str,
+    force_unix_eol: bool = False,
+) -> None:
     """
     Export roles to a YAML file.
     """
     auth = ctx.obj["AUTH"]
     url = URL(ctx.obj["INSTANCE"])
     client = SupersetClient(url, auth)
 
-    with open(path, "w", encoding="utf-8") as output:
+    newline = get_newline_char(force_unix_eol)
+    with open(path, "w", encoding="utf-8", newline=newline) as output:
         yaml.dump(list(client.export_roles()), output)
 
 
@@ -263,16 +300,27 @@ def export_roles(ctx: click.core.Context, path: str) -> None:
     type=click.Path(resolve_path=True),
     default="rls.yaml",
 )
+@click.option(
+    "--force-unix-eol",
+    is_flag=True,
+    default=False,
+    help="Force Unix end-of-line characters, otherwise use system default",
+)
 @click.pass_context
-def export_rls(ctx: click.core.Context, path: str) -> None:
+def export_rls(
+    ctx: click.core.Context,
+    path: str,
+    force_unix_eol: bool = False,
+) -> None:
     """
     Export RLS rules to a YAML file.
     """
     auth = ctx.obj["AUTH"]
     url = URL(ctx.obj["INSTANCE"])
     client = SupersetClient(url, auth)
 
-    with open(path, "w", encoding="utf-8") as output:
+    newline = get_newline_char(force_unix_eol)
+    with open(path, "w", encoding="utf-8", newline=newline) as output:
         yaml.dump(list(client.export_rls()), output, sort_keys=False)
 
 
@@ -282,8 +330,18 @@ def export_rls(ctx: click.core.Context, path: str) -> None:
     type=click.Path(resolve_path=True),
     default="ownership.yaml",
 )
+@click.option(
+    "--force-unix-eol",
+    is_flag=True,
+    default=False,
+    help="Force Unix end-of-line characters, otherwise use system default",
+)
 @click.pass_context
-def export_ownership(ctx: click.core.Context, path: str) -> None:
+def export_ownership(
+    ctx: click.core.Context,
+    path: str,
+    force_unix_eol: bool = False,
+) -> None:
     """
     Export DBs/datasets/charts/dashboards ownership to a YAML file.
     """
@@ -302,5 +360,6 @@ def export_ownership(ctx: click.core.Context, path: str) -> None:
                 },
             )
 
-    with open(path, "w", encoding="utf-8") as output:
+    newline = get_newline_char(force_unix_eol)
+    with open(path, "w", encoding="utf-8", newline=newline) as output:
         yaml.dump(dict(ownership), output)