Fix OS compatibility issues for editors with spaces, slashes, and quotes (#1153)

* Fix inverted POSIX check, refactor os_compat, and add tests for it
* Fix missing parentheses and remove skip_win on test that is passing in Windows now
* Fix expected quotes in quoted args
* Make  output clearer on failing test
* Bringing skip_win back to test whose failure is a bit more complicated than expected

features/steps/core.py

@@ -6,7 +6,6 @@ from collections import defaultdict
 import os
 from pathlib import Path
 import re
-import shlex
 import time
 from unittest.mock import patch
 
@@ -23,7 +22,7 @@ from jrnl import __version__
 from jrnl import plugins
 from jrnl.cli import cli
 from jrnl.config import load_config
-from jrnl.os_compat import on_windows
+from jrnl.os_compat import split_args
 
 try:
     import parsedatetime.parsedatetime_consts as pdt
@@ -88,10 +87,6 @@ class FailedKeyring(keyring.backend.KeyringBackend):
 keyring.set_keyring(TestKeyring())
 
 
-def ushlex(command):
-    return shlex.split(command, posix=not on_windows)
-
-
 def read_journal(context, journal_name="default"):
     configuration = load_config(context.config_path)
     with open(configuration["journals"][journal_name]) as journal_file:
@@ -319,7 +314,7 @@ def run_with_input(context, command, inputs=""):
     else:
         text = iter([inputs])
 
-    args = ushlex(command)[1:]
+    args = split_args(command)[1:]
 
     def _mock_editor(command):
         context.editor_command = command
@@ -403,7 +398,7 @@ def run(context, command, text=""):
         cache_dir = os.path.join("features", "cache", context.cache_dir)
         command = command.format(cache_dir=cache_dir)
 
-    args = ushlex(command)
+    args = split_args(command)
 
     def _mock_editor(command):
         context.editor_command = command