Allow runtime configuration overrides from the commandline (#1169)

Add --config-override feature

* add test and argument handler for runtime override of configurations.
* identify location to apply override in "main"
* update gitignore
* remove unneeded import
* add jrnl interface test for overriden configurations
* trivial whitespace change
* implement runtime override
* make format
* refactor override unittest
* clean up unused import
* start writing integration test
* add linewrap override scenario
* implement editor override step
* add dev dependencies on pytest -mock and -cov
* make format
* remove unused imports
* make format
* rename --override to --config-override
* move override implementation into own module
* begin TDD of dot notated overrides
* rewrite behavior scenario
* implement recursive config overrides
* clean up unittests
* iterate on behave step
* make format
* cleanup
* move override behave tests out of core
* refactor recursive code
* make format
* code cleanup
* remove unused import
* update test config
* rewrite test for better mock call expect
* make format
* binary search misbehaving windows test
* unittest multiple overrides
* uncomment dot notation unittest
* add multiple override scenario spec
* make format
* make format
* update unittests for new syntax
* update integ tests for new syntax
* update gitignore
* guard override application
* deserialize function as return type
* make format
* organize deserialization unittests
* better, more specific behave tests
* test different editor launch commands
* formatting
* handle datatypes in deserialization and update helptext
* stick to config convention in testbed
* update tests ith better verifications
* make format
* space
* review feedbac
* make format
* skip on win
* update deps
* update tests with better verifications
make format
space
review feedbac
* skip on win
* update deps
* refactor deserialization
organize test_parse_args
make format
* skip on win
* refactor deserialization
organize test_parse_args
make format
* update tests ith better verifications
* make format
* space
* make format
* document apply_overrides
* update gitignore
* document config-override enhancement
* Simplify config override syntax (#5)
* update tests and expected behavior
* clean up arg parsing tests
* update deserialization
* update deserialization
* config argparse action
* update override application logic
* update tests; delete unused imports
* override param must be list
* update docstring
* update test input to SUT
* update remaining override unittests
* make format
* forgot to update CLI syntax
* update documentation to sphinx style
* variable renames
* Lockfile merge (#7)
* Add brew and gitter badges to README
* Update changelog [ci skip]
* Make journal selection behavior more consistent when there's a colon with no date (#1164)
* Simplify config override syntax (#8)
* update tests and expected behavior
* clean up arg parsing tests
* update deserialization
* update deserialization
* config argparse action
* update override application logic
* update tests; delete unused imports
* override param must be list
* update docstring
* update test input to SUT
* update remaining override unittests
* make format
* forgot to update CLI syntax
* formatting
* Update pyproject.toml
* update lockfile to remove pytest-cov and pytest-mock deps
* update docs
* reuse existing mock; delete unneeded code
* move overrides earlier in the execution
use existing configs instead of custom
make format
clean up imports
* update for passworded access
context.parser -> parsed_args
* test that no editor is launched
* remove unnecessary mocks
* rename variable for intent
* reinstate getpass deletion
* update gitignore
* capture failure mode
* remove unneeded imports
* renamed variable
* delete redundant step
* comment on step
* clean up step behavior description
* [WIP] lock down journal access behavior
* skip -> wip
* correct command for overriding journal via dot keys
* update wip test for updating a "temp" journal and then reading baack its entries
* remove "mock" from poetry file
* make CI happy
* complex behavior sequence for default journal override
* separate out smaller pieces of logic
test that apply_overrides acts on base configuration and not the copy
* defer modification of loaded configuration to update_config
remove unused fixtures
delete complicated UT since behavior is covered in overrides.feature integ test
delete redundant UT
* Update .gitignore
* remove skip_win
* forward override unpacking to yaml library
* merge config override step with existing config_var step in core
delete config_override step
unify step description syntax
* delete unused and redundant code
* rebases are hard
* remove wip tag from test
* remove skipped tests for windows
* Address code review
yield -> return
remove needless copy
adjust spacing
re-inline args return
reset packaging info to e6c0a16342a31bc2fca1e2e865646c27bd43d0b4
revert package version for this PR
* consolidate imports
* Defer config_override unpacking to dict *after* base config is loaded
store cli overrides without unpacking just yet
move deserialize_config_args to config module
delete custom Action class for config operations
apply [k,v] -> {k, v} for each override
update test data
update import
* rename deserialize_config_args to better express intent
make format

12 files changed, 526 insertions, 4 deletions

diff --git a/.gitignore b/.gitignore
index afb0d874..374deb4b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -54,3 +54,10 @@ exp/
 _extras/
 *.sublime-*
 site/
+
+.vscode/settings.json
+coverage.xml
+.vscode/launch.json
+.coverage
+.vscode/tasks.json
+todo.txt
diff --git a/docs/advanced.md b/docs/advanced.md
index 10da134b..b1b7bef0 100644
--- a/docs/advanced.md
+++ b/docs/advanced.md
@@ -62,6 +62,29 @@ and can be edited with a plain text editor.
   Or use the built-in prompt or an external editor to compose your
   entries.
 
+### Modifying Configurations from the Command line 
+
+You can override a configuration field for the current instance of `jrnl` using `--config-override CONFIG_KEY CONFIG_VALUE` where `CONFIG_KEY` is a valid configuration field, specified in dot-notation and `CONFIG_VALUE` is the (valid) desired override value.
+
+You can specify multiple overrides as multiple calls to `--config-override`.
+!!! note
+    These overrides allow you to modify ***any*** field of your jrnl configuration. We trust that you know what you are doing. 
+
+#### Examples: 
+
+``` sh
+#Create an entry using the `stdin` prompt, for rapid logging
+jrnl --config-override editor ""
+
+#Populate a project's log
+jrnl --config-override journals.todo "$(git rev-parse --show-toplevel)/todo.txt" todo find my towel 
+
+#Pass multiple overrides 
+jrnl --config-override display_format fancy --config-override linewrap 20 \
+--config-override colors.title green
+
+```
+
 ## Multiple journal files
 
 You can configure `jrnl`to use with multiple journals (eg.
diff --git a/docs/recipes.md b/docs/recipes.md
index 14e08e14..ef45666a 100644
--- a/docs/recipes.md
+++ b/docs/recipes.md
@@ -154,6 +154,33 @@ only field 1.
 jrnl -on "$(jrnl --short | shuf -n 1 | cut -d' ' -f1,2)"
 ```
 
+
+### Launch a terminal for rapid logging 
+You can use this to launch a terminal that is the `jrnl` stdin prompt so you can start typing away immediately. 
+
+```bash
+jrnl now --config-override editor:""
+```
+
+Bind this to a keyboard shortcut. 
+
+Map `Super+Alt+J` to launch the terminal with jrnl prompt
+
+- **xbindkeys**
+In your `.xbindkeysrc`
+
+```ini
+Mod4+Mod1+j
+ alacritty -t floating-jrnl -e jrnl now --config-override editor:"",
+```
+
+- **I3 WM** Launch a floating terminal with the `jrnl` prompt
+
+```ini
+bindsym Mod4+Mod1+j exec --no-startup-id alacritty -t floating-jrnl -e jrnl --config-override editor:""
+for_window[title="floating *"] floating enable
+```
+
 ## External editors
 
 Configure your preferred external editor by updating the `editor` option 
diff --git a/features/overrides.feature b/features/overrides.feature
new file mode 100644
index 00000000..e0cdd9f0
--- /dev/null
+++ b/features/overrides.feature
@@ -0,0 +1,98 @@
+Feature: Implementing Runtime Overrides for Select Configuration Keys
+
+        Scenario: Override configured editor with built-in input === editor:''
+        Given we use the config "basic_encrypted.yaml"
+        And we use the password "test" if prompted
+        When we run "jrnl --config-override editor ''"
+        Then the stdin prompt should have been called
+        
+        Scenario: Postconfig commands with overrides
+        Given We use the config "basic_encrypted.yaml"
+        And we use the password "test" if prompted
+        When we run "jrnl --decrypt --config-override highlight false --config-override editor nano"
+        Then the config should have "highlight" set to "bool:false"
+        And no editor should have been called
+        
+        Scenario: Override configured linewrap with a value of 23
+        Given we use the config "simple.yaml"
+        And we use the password "test" if prompted
+        When we run "jrnl  -2 --config-override linewrap 23 --format fancy"
+        Then the output should be
+
+        """
+        ┎─────╮2013-06-09 15:39
+        ┃ My  ╘═══════════════╕
+        ┃ fir st  ent ry.     │
+        ┠╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
+        ┃ Everything is       │
+        ┃ alright             │
+        ┖─────────────────────┘
+        ┎─────╮2013-06-10 15:40
+        ┃ Lif ╘═══════════════╕
+        ┃ e is  goo d.        │
+        ┠╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
+        ┃ But I'm better.     │
+        ┖─────────────────────┘
+        """
+
+        Scenario: Override color selections with runtime overrides 
+        Given we use the config "basic_encrypted.yaml"
+        And we use the password "test" if prompted
+        When we run "jrnl -1 --config-override colors.body blue"
+        Then the config should have "colors.body" set to "blue"
+
+        Scenario: Apply multiple config overrides 
+        Given we use the config "basic_encrypted.yaml"
+        And we use the password "test" if prompted 
+        When we run "jrnl -1 --config-override colors.body green --config-override editor 'nano'"
+        Then the config should have "colors.body" set to "green" 
+        And the config should have "editor" set to "nano"
+
+
+        Scenario Outline: Override configured editor
+        Given we use the config "basic_encrypted.yaml"
+        And we use the password "test" if prompted 
+        When we run "jrnl --config-override editor '<editor>'"
+        Then the editor <editor> should have been called
+        Examples: Editor Commands
+        | editor            |
+        | nano              |
+        | vi -c startinsert | 
+        | code -w           | 
+
+        Scenario: Override default journal
+        Given we use the config "basic_dayone.yaml"
+        And we use the password "test" if prompted
+        When we run "jrnl --debug --config-override journals.default features/journals/simple.journal 20 Mar 2000: The rain in Spain comes from clouds"
+        Then we should get no error
+        And we should see the message "Entry added"
+        When we run "jrnl -3 --debug --config-override journals.default features/journals/simple.journal"
+        Then the output should be 
+        """
+        2000-03-20 09:00 The rain in Spain comes from clouds
+
+        2013-06-09 15:39 My first entry.
+        | Everything is alright
+      
+        2013-06-10 15:40 Life is good.
+        | But I'm better.
+        """
+        
+
+        Scenario: Make an entry into an overridden journal 
+        Given we use the config "basic_dayone.yaml"
+        And we use the password "test" if prompted
+        When we run "jrnl --config-override journals.temp features/journals/simple.journal temp Sep 06 1969: @say Ni"
+        Then we should get no error
+        And we should see the message "Entry added"
+        When we run "jrnl --config-override journals.temp features/journals/simple.journal temp -3" 
+        Then the output should be 
+        """
+        1969-09-06 09:00 @say Ni
+
+        2013-06-09 15:39 My first entry.
+        | Everything is alright
+        
+        2013-06-10 15:40 Life is good.
+        | But I'm better.
+        """
diff --git a/features/steps/core.py b/features/steps/core.py
index abac4917..f471acfb 100644
--- a/features/steps/core.py
+++ b/features/steps/core.py
@@ -3,6 +3,7 @@
 
 import ast
 from collections import defaultdict
+from jrnl.args import parse_args
 import os
 from pathlib import Path
 import re
@@ -13,8 +14,11 @@ from behave import given
 from behave import then
 from behave import when
 import keyring
+
 import toml
 import yaml
+from yaml.loader import FullLoader
+
 
 import jrnl.time
 from jrnl import Journal
@@ -23,6 +27,7 @@ from jrnl import plugins
 from jrnl.cli import cli
 from jrnl.config import load_config
 from jrnl.os_compat import split_args
+from jrnl.override import apply_overrides, _recursively_apply
 
 try:
     import parsedatetime.parsedatetime_consts as pdt
@@ -114,8 +119,15 @@ def read_value_from_string(string):
         return ast.literal_eval(string)
 
     # Takes strings like "bool:true" or "int:32" and coerces them into proper type
-    t, value = string.split(":")
-    value = {"bool": lambda v: v.lower() == "true", "int": int, "str": str}[t](value)
+    string_parts = string.split(":")
+    if len(string_parts) > 1:
+        type = string_parts[0]
+        value = string_parts[1:][0]  # rest of the text
+        value = {"bool": lambda v: v.lower() == "true", "int": int, "str": str}[type](
+            value
+        )
+    else:
+        value = string_parts[0]
     return value
 
 
@@ -315,6 +327,7 @@ def run_with_input(context, command, inputs=""):
         text = iter([inputs])
 
     args = split_args(command)[1:]
+    context.args = args
 
     def _mock_editor(command):
         context.editor_command = command
@@ -397,8 +410,13 @@ def run(context, command, text=""):
     if "cache_dir" in context and context.cache_dir is not None:
         cache_dir = os.path.join("features", "cache", context.cache_dir)
         command = command.format(cache_dir=cache_dir)
+    if "config_path" in context and context.config_path is not None:
+        with open(context.config_path, "r") as f:
+            cfg = yaml.load(f, Loader=FullLoader)
+        context.jrnl_config = cfg
 
     args = split_args(command)
+    context.args = args[1:]
 
     def _mock_editor(command):
         context.editor_command = command
@@ -604,14 +622,29 @@ def journal_exists(context, journal_name="default"):
 @then('the config should have "{key}" set to "{value}"')
 @then('the config for journal "{journal}" should have "{key}" set to "{value}"')
 def config_var(context, key, value="", journal=None):
+    key_as_vec = key.split(".")
+
+    if "args" in context:
+        parsed = parse_args(context.args)
+        overrides = parsed.config_override
     value = read_value_from_string(value or context.text or "")
     configuration = load_config(context.config_path)
 
     if journal:
         configuration = configuration["journals"][journal]
 
-    assert key in configuration
-    assert configuration[key] == value
+    if overrides:
+        with patch.object(
+            jrnl.override, "_recursively_apply", wraps=_recursively_apply
+        ) as spy_recurse:
+            configuration = apply_overrides(overrides, configuration)
+            runtime_cfg = spy_recurse.call_args_list[0][0][0]
+    else:
+        runtime_cfg = configuration
+        # extract the value of the desired key from the configuration after overrides have been applied
+    for k in key_as_vec:
+        runtime_cfg = runtime_cfg["%s" % k]
+    assert runtime_cfg == value
 
 
 @then('the config for journal "{journal}" should not have "{key}" set')
diff --git a/features/steps/override.py b/features/steps/override.py
new file mode 100644
index 00000000..ff1760ed
--- /dev/null
+++ b/features/steps/override.py
@@ -0,0 +1,77 @@
+from jrnl.jrnl import run
+from unittest import mock
+
+# from __future__ import with_statement
+from jrnl.args import parse_args
+from behave import then
+
+from features.steps.core import _mock_getpass, _mock_time_parse
+
+
+@then("the editor {editor} should have been called")
+@then("No editor should have been called")
+def editor_override(context, editor=None):
+    def _mock_write_in_editor(config):
+        editor = config["editor"]
+        journal = "features/journals/journal.jrnl"
+        context.tmpfile = journal
+        print("%s has been launched" % editor)
+        return journal
+
+    if "password" in context:
+        password = context.password
+    else:
+        password = ""
+    # fmt: off
+    # see: https://github.com/psf/black/issues/664
+    with \
+        mock.patch("jrnl.jrnl._write_in_editor", side_effect=_mock_write_in_editor(context.jrnl_config)) as mock_write_in_editor, \
+        mock.patch("sys.stdin.isatty", return_value=True), \
+        mock.patch('getpass.getpass',side_effect=_mock_getpass(password)), \
+        mock.patch("jrnl.time.parse", side_effect = _mock_time_parse(context)), \
+        mock.patch("jrnl.config.get_config_path", side_effect=lambda: context.config_path), \
+        mock.patch("jrnl.install.get_config_path", side_effect=lambda: context.config_path) \
+    :
+        try :
+                parsed_args = parse_args(context.args)
+                run(parsed_args)
+                context.exit_status = 0
+                context.editor = mock_write_in_editor
+                expected_config = context.jrnl_config
+                expected_config['editor'] = '%s'%editor 
+                expected_config['journal'] ='features/journals/journal.jrnl'
+
+                if editor is not None:
+                    assert mock_write_in_editor.call_count == 1
+                    assert mock_write_in_editor.call_args[0][0]['editor']==editor
+                else: 
+                    # Expect that editor is *never* called
+                    mock_write_in_editor.assert_not_called() 
+        except SystemExit as e:
+            context.exit_status = e.code
+    # fmt: on
+
+
+@then("the stdin prompt should have been called")
+def override_editor_to_use_stdin(context):
+
+    try:
+        with mock.patch(
+            "sys.stdin.read",
+            return_value="Zwei peanuts walk into a bar und one of zem was a-salted",
+        ) as mock_stdin_read, mock.patch(
+            "jrnl.install.load_or_install_jrnl", return_value=context.jrnl_config
+        ), mock.patch(
+            "jrnl.Journal.open_journal",
+            spec=False,
+            return_value="features/journals/journal.jrnl",
+        ), mock.patch(
+            "getpass.getpass", side_effect=_mock_getpass("test")
+        ):
+            parsed_args = parse_args(context.args)
+            run(parsed_args)
+            context.exit_status = 0
+        mock_stdin_read.assert_called_once()
+
+    except SystemExit as e:
+        context.exit_status = e.code
diff --git a/jrnl/args.py b/jrnl/args.py
index f934ca16..c8bd7743 100644
--- a/jrnl/args.py
+++ b/jrnl/args.py
@@ -314,6 +314,29 @@ def parse_args(args=[]):
         help=argparse.SUPPRESS,
     )
 
+    config_overrides = parser.add_argument_group(
+        "Config file override",
+        textwrap.dedent("Apply a one-off override of the config file option"),
+    )
+    config_overrides.add_argument(
+        "--config-override",
+        dest="config_override",
+        action="append",
+        type=str,
+        nargs=2,
+        default=[],
+        metavar="CONFIG_KV_PAIR",
+        help="""
+        Override configured key-value pair with CONFIG_KV_PAIR for this command invocation only.
+
+        Examples: \n
+        \t - Use a different editor for this jrnl entry, call: \n
+            \t jrnl --config-override editor: "nano" \n
+        \t - Override color selections\n
+           \t jrnl --config-override colors.body blue --config-override colors.title green
+        """,
+    )
+
     # Handle '-123' as a shortcut for '-n 123'
     num = re.compile(r"^-(\d+)$")
     args = [num.sub(r"-n \1", arg) for arg in args]
diff --git a/jrnl/config.py b/jrnl/config.py
index a5a1d1cc..da2df2cc 100644
--- a/jrnl/config.py
+++ b/jrnl/config.py
@@ -19,6 +19,32 @@ XDG_RESOURCE = "jrnl"
 DEFAULT_JOURNAL_NAME = "journal.txt"
 DEFAULT_JOURNAL_KEY = "default"
 
+YAML_SEPARATOR = ": "
+
+
+def make_yaml_valid_dict(input: list) -> dict:
+
+    """
+
+    Convert a two-element list of configuration key-value pair into a flat dict.
+
+    The dict is created through the yaml loader, with the assumption that
+    "input[0]: input[1]" is valid yaml.
+
+    :param input: list of configuration keys in dot-notation and their respective values.
+    :type input: list
+    :return: A single level dict of the configuration keys in dot-notation and their respective desired values
+    :rtype: dict
+    """
+
+    assert len(input) == 2
+
+    # yaml compatible strings are of the form Key:Value
+    yamlstr = YAML_SEPARATOR.join(input)
+    runtime_modifications = yaml.load(yamlstr, Loader=yaml.FullLoader)
+
+    return runtime_modifications
+
 
 def save_config(config):
     config["version"] = __version__
diff --git a/jrnl/jrnl.py b/jrnl/jrnl.py
index 257358c4..383cceee 100644
--- a/jrnl/jrnl.py
+++ b/jrnl/jrnl.py
@@ -16,6 +16,7 @@ from .editor import get_text_from_editor
 from .editor import get_text_from_stdin
 from .exception import UserAbort
 from . import time
+from .override import apply_overrides
 
 
 def run(args):
@@ -37,6 +38,12 @@ def run(args):
     try:
         config = install.load_or_install_jrnl()
         original_config = config.copy()
+
+        # Apply config overrides
+        overrides = args.config_override
+        if overrides:
+            config = apply_overrides(overrides, config)
+
         args = get_journal_name(args, config)
         config = scope_config(config, args.journal_name)
     except UserAbort as err:
diff --git a/jrnl/override.py b/jrnl/override.py
new file mode 100644
index 00000000..7fd718f0
--- /dev/null
+++ b/jrnl/override.py
@@ -0,0 +1,65 @@
+from .config import update_config, make_yaml_valid_dict
+
+# import logging
+def apply_overrides(overrides: list, base_config: dict) -> dict:
+    """Unpack CLI provided overrides into the configuration tree.
+
+    :param overrides: List of configuration key-value pairs collected from the CLI
+    :type overrides: list
+    :param base_config: Configuration Loaded from the saved YAML
+    :type base_config: dict
+    :return: Configuration to be used during runtime with the overrides applied
+    :rtype: dict
+    """
+    cfg_with_overrides = base_config.copy()
+    for pairs in overrides:
+
+        pairs = make_yaml_valid_dict(pairs)
+        key_as_dots, override_value = _get_key_and_value_from_pair(pairs)
+        keys = _convert_dots_to_list(key_as_dots)
+        cfg_with_overrides = _recursively_apply(
+            cfg_with_overrides, keys, override_value
+        )
+
+    update_config(base_config, cfg_with_overrides, None)
+    return base_config
+
+
+def _get_key_and_value_from_pair(pairs):
+    key_as_dots, override_value = list(pairs.items())[0]
+    return key_as_dots, override_value
+
+
+def _convert_dots_to_list(key_as_dots):
+    keys = key_as_dots.split(".")
+    keys = [k for k in keys if k != ""]  # remove empty elements
+    return keys
+
+
+def _recursively_apply(tree: dict, nodes: list, override_value) -> dict:
+    """Recurse through configuration and apply overrides at the leaf of the config tree
+
+    Credit to iJames on SO: https://stackoverflow.com/a/47276490 for algorithm
+
+    Args:
+        config (dict): Configuration to modify
+        nodes (list): Vector of override keys; the length of the vector indicates tree depth
+        override_value (str): Runtime override passed from the command-line
+    """
+    key = nodes[0]
+    if len(nodes) == 1:
+        tree[key] = override_value
+    else:
+        next_key = nodes[1:]
+        next_node = _get_config_node(tree, key)
+        _recursively_apply(next_node, next_key, override_value)
+
+    return tree
+
+
+def _get_config_node(config: dict, key: str):
+    if key in config:
+        pass
+    else:
+        config[key] = None
+    return config[key]
diff --git a/tests/test_override.py b/tests/test_override.py
new file mode 100644
index 00000000..32ec0595
--- /dev/null
+++ b/tests/test_override.py
@@ -0,0 +1,79 @@
+import pytest
+
+from jrnl.override import (
+    apply_overrides,
+    _recursively_apply,
+    _get_config_node,
+    _get_key_and_value_from_pair,
+    _convert_dots_to_list,
+)
+
+
+@pytest.fixture()
+def minimal_config():
+    cfg = {
+        "colors": {"body": "red", "date": "green"},
+        "default": "/tmp/journal.jrnl",
+        "editor": "vim",
+        "journals": {"default": "/tmp/journals/journal.jrnl"},
+    }
+    return cfg
+
+
+def test_apply_override(minimal_config):
+    overrides = [["editor", "nano"]]
+    apply_overrides(overrides, minimal_config)
+    assert minimal_config["editor"] == "nano"
+
+
+def test_override_dot_notation(minimal_config):
+    overrides = [["colors.body", "blue"]]
+
+    cfg = apply_overrides(overrides=overrides, base_config=minimal_config)
+    assert cfg["colors"] == {"body": "blue", "date": "green"}
+
+
+def test_multiple_overrides(minimal_config):
+    overrides = [
+        ["colors.title", "magenta"],
+        ["editor", "nano"],
+        ["journals.burner", "/tmp/journals/burner.jrnl"],
+    ]  # as returned by parse_args, saved in parser.config_override
+
+    cfg = apply_overrides(overrides, minimal_config)
+    assert cfg["editor"] == "nano"
+    assert cfg["colors"]["title"] == "magenta"
+    assert "burner" in cfg["journals"]
+    assert cfg["journals"]["burner"] == "/tmp/journals/burner.jrnl"
+
+
+def test_recursively_apply():
+    cfg = {"colors": {"body": "red", "title": "green"}}
+    cfg = _recursively_apply(cfg, ["colors", "body"], "blue")
+    assert cfg["colors"]["body"] == "blue"
+
+
+def test_get_config_node(minimal_config):
+    assert len(minimal_config.keys()) == 4
+    assert _get_config_node(minimal_config, "editor") == "vim"
+    assert _get_config_node(minimal_config, "display_format") == None
+
+
+def test_get_kv_from_pair():
+    pair = {"ab.cde": "fgh"}
+    k, v = _get_key_and_value_from_pair(pair)
+    assert k == "ab.cde"
+    assert v == "fgh"
+
+
+class TestDotNotationToList:
+    def test_unpack_dots_to_list(self):
+
+        keys = "a.b.c.d.e.f"
+        keys_list = _convert_dots_to_list(keys)
+        assert len(keys_list) == 6
+
+    def test_sequential_delimiters(self):
+        k = "g.r..h.v"
+        k_l = _convert_dots_to_list(k)
+        assert len(k_l) == 4
diff --git a/tests/test_parse_args.py b/tests/test_parse_args.py
index 252638c9..4b140fc1 100644
--- a/tests/test_parse_args.py
+++ b/tests/test_parse_args.py
@@ -3,6 +3,7 @@ import shlex
 import pytest
 
 from jrnl.args import parse_args
+from jrnl.config import make_yaml_valid_dict
 
 
 def cli_as_dict(str):
@@ -35,6 +36,7 @@ def expected_args(**kwargs):
         "strict": False,
         "tags": False,
         "text": [],
+        "config_override": [],
     }
     return {**default_args, **kwargs}
 
@@ -205,6 +207,31 @@ def test_version_alone():
     assert cli_as_dict("--version") == expected_args(preconfig_cmd=preconfig_version)
 
 
+def test_editor_override():
+
+    parsed_args = cli_as_dict('--config-override editor "nano"')
+    assert parsed_args == expected_args(config_override=[["editor", "nano"]])
+
+
+def test_color_override():
+    assert cli_as_dict("--config-override colors.body blue") == expected_args(
+        config_override=[["colors.body", "blue"]]
+    )
+
+
+def test_multiple_overrides():
+    parsed_args = cli_as_dict(
+        '--config-override colors.title green --config-override editor "nano" --config-override journal.scratchpad "/tmp/scratchpad"'
+    )
+    assert parsed_args == expected_args(
+        config_override=[
+            ["colors.title", "green"],
+            ["editor", "nano"],
+            ["journal.scratchpad", "/tmp/scratchpad"],
+        ]
+    )
+
+
 # @see https://github.com/jrnl-org/jrnl/issues/520
 @pytest.mark.parametrize(
     "cli",
@@ -233,3 +260,33 @@ def test_and_ordering(cli):
 def test_edit_ordering(cli):
     result = expected_args(edit=True, text=["second", "@oldtag", "@newtag"])
     assert cli_as_dict(cli) == result
+
+
+class TestDeserialization:
+    @pytest.mark.parametrize(
+        "input_str",
+        [
+            ["editor", "nano"],
+            ["colors.title", "blue"],
+            ["default", "/tmp/egg.txt"],
+        ],
+    )
+    def test_deserialize_multiword_strings(self, input_str):
+
+        runtime_config = make_yaml_valid_dict(input_str)
+        assert runtime_config.__class__ == dict
+        assert input_str[0] in runtime_config.keys()
+        assert runtime_config[input_str[0]] == input_str[1]
+
+    def test_deserialize_multiple_datatypes(self):
+        cfg = make_yaml_valid_dict(["linewrap", "23"])
+        assert cfg["linewrap"] == 23
+
+        cfg = make_yaml_valid_dict(["encrypt", "false"])
+        assert cfg["encrypt"] == False
+
+        cfg = make_yaml_valid_dict(["editor", "vi -c startinsert"])
+        assert cfg["editor"] == "vi -c startinsert"
+
+        cfg = make_yaml_valid_dict(["highlight", "true"])
+        assert cfg["highlight"] == True