[FEATURE] Add __value__ to subscription files to be able to create one-liner subs (#641)

* [FEATURE] Add __value__ to subscription files to create one-liner subs

* docs

docs/config.rst

@@ -306,6 +306,32 @@ by using the file-wide ``__preset__``:
 This ``subscription.yaml`` is equivalent to the one above it because all
 subscriptions automatically set ``__preset__`` as a `parent preset`_.
 
+File Subscription Value
+^^^^^^^^^^^^^^^^^^^^^^^
+With a clever config and use of ``__preset__``, your subscriptions can typically boil
+down to a name and url. You can set ``__value__`` to the name of an override variable,
+and use the override variable ``subscription_name`` to achieve one-liner subscriptions.
+Using the example above, we can do:
+
+.. code-block:: yaml
+  :caption: subscription.yaml
+
+   __preset__:
+     preset: "playlist_preset_ex"
+     overrides:
+       playlist_name: "{subscription_name}"
+
+   __value__: "url"
+
+   # single-line subscription
+   "diy-playlist": "https://youtube.com/playlist?list=UCsvn_Po0SmunchJYtttWpOxMg"
+
+``"diy-playlist"`` gets assigned to the ``playlist_name`` override variable by setting
+it with ``subscription_name`` , and the url gets assigned to ``url`` by setting ``__value__``
+to write values to it.
+
+Traditional subscriptions that can override presets will still work when using ``__value__``.
+
 -------------------------------------------------------------------------------
 
 .. _source-variables:

src/ytdl_sub/subscriptions/subscription.py

@@ -5,10 +5,12 @@ from typing import List
 from ytdl_sub.config.config_file import ConfigFile
 from ytdl_sub.config.preset import Preset
 from ytdl_sub.subscriptions.subscription_download import SubscriptionDownload
+from ytdl_sub.utils.exceptions import ValidationException
 from ytdl_sub.utils.yaml import load_yaml
 from ytdl_sub.validators.validators import LiteralDictValidator
 
 FILE_PRESET_APPLY_KEY = "__preset__"
+FILE_SUBSCRIPTION_VALUE_KEY = "__value__"
 
 
 class Subscription(SubscriptionDownload):
@@ -64,7 +66,9 @@ class Subscription(SubscriptionDownload):
     @classmethod
     def from_file_path(cls, config: ConfigFile, subscription_path: str) -> List["Subscription"]:
         """
-        Loads subscriptions from a file and applies __preset__ to all of them if present.
+        Loads subscriptions from a file and applies ``__preset__`` to all of them if present.
+        If a subscription is in the form of key: value, it will set value to the override
+        variable defined in ``__value__``.
 
         Parameters
         ----------
@@ -76,11 +80,17 @@ class Subscription(SubscriptionDownload):
         Returns
         -------
         List of subscriptions, for each one in the subscription yaml
+
+        Raises
+        ------
+        ValidationException
+            If subscription file is misconfigured
         """
         subscriptions: List["Subscription"] = []
         subscription_dict = load_yaml(file_path=subscription_path)
 
         has_file_preset = FILE_PRESET_APPLY_KEY in subscription_dict
+        has_file_subscription_value = FILE_SUBSCRIPTION_VALUE_KEY in subscription_dict
 
         # If a file preset is present...
         if has_file_preset:
@@ -94,12 +104,39 @@ class Subscription(SubscriptionDownload):
             config = copy.deepcopy(config)
             config.presets.dict[FILE_PRESET_APPLY_KEY] = file_preset.dict
 
+        if has_file_subscription_value:
+            if not isinstance(subscription_dict[FILE_SUBSCRIPTION_VALUE_KEY], str):
+                raise ValidationException(
+                    f"Using {FILE_SUBSCRIPTION_VALUE_KEY} in a subscription"
+                    f"must be a string that corresponds to an override variable"
+                )
+
         for subscription_key, subscription_object in subscription_dict.items():
 
-            # Skip file preset
+            # Skip file preset or value
-            if subscription_key == FILE_PRESET_APPLY_KEY:
+            if subscription_key in [FILE_PRESET_APPLY_KEY, FILE_SUBSCRIPTION_VALUE_KEY]:
                 continue
 
+            # If the subscription obj is just a string, set it to the override variable
+            # defined in FILE_SUBSCRIPTION_VALUE_KEY
+            if isinstance(subscription_object, str) and has_file_subscription_value:
+                subscription_object = {
+                    "overrides": {
+                        subscription_dict[FILE_SUBSCRIPTION_VALUE_KEY]: subscription_object
+                    }
+                }
+            elif isinstance(subscription_object, dict):
+                pass
+            elif isinstance(subscription_object, str) and not has_file_subscription_value:
+                raise ValidationException(
+                    f"Subscription {subscription_key} is a string, but "
+                    f"{FILE_SUBSCRIPTION_VALUE_KEY} is not set to an override variable"
+                )
+            else:
+                raise ValidationException(
+                    f"Subscription {subscription_key} should be in the form of a preset"
+                )
+
             # If it has file_preset, inject it as a parent preset
             if has_file_preset:
                 parent_preset = subscription_object.get("preset", [])

tests/unit/config/test_subscription.py

@@ -1,3 +1,4 @@
+import re
 from typing import Dict
 from unittest.mock import patch
 
@@ -5,44 +6,134 @@ import pytest
 
 from ytdl_sub.config.config_file import ConfigFile
 from ytdl_sub.plugins.nfo_tags import NfoTagsOptions
+from ytdl_sub.subscriptions.subscription import FILE_SUBSCRIPTION_VALUE_KEY
 from ytdl_sub.subscriptions.subscription import Subscription
+from ytdl_sub.utils.exceptions import ValidationException
 
 
 @pytest.fixture
-def preset_file(youtube_video: Dict, output_options: Dict) -> Dict:
+def preset_file(youtube_video: Dict, output_options: Dict):
-    return {
+    with patch("ytdl_sub.subscriptions.subscription.load_yaml") as mock_load_yaml:
-        "__preset__": {
+        mock_load_yaml.return_value = {
-            "download": youtube_video,
+            "__preset__": {
-            "output_options": output_options,
+                "download": youtube_video,
-            "nfo_tags": {
+                "output_options": output_options,
-                "tags": {"key-3": "file_preset"},
+                "nfo_tags": {
+                    "tags": {"key-3": "file_preset"},
+                },
+                "overrides": {"test_override": "original"},
             },
-        },
+            "__value__": "test_override",
-        "test_preset": {
+            "test_preset": {
-            "preset": "parent_preset_3",
+                "preset": "parent_preset_3",
-            "nfo_tags": {
+                "nfo_tags": {
-                "tags": {"key-4": "test_preset"},
+                    "tags": {"key-4": "test_preset"},
+                },
             },
-        },
+        }
+        yield
+
+
+@pytest.fixture
+def preset_file_with_value(youtube_video: Dict, output_options: Dict):
+    with patch("ytdl_sub.subscriptions.subscription.load_yaml") as mock_load_yaml:
+        mock_load_yaml.return_value = {
+            "__preset__": {
+                "preset": "parent_preset_3",
+                "download": youtube_video,
+                "output_options": output_options,
+                "nfo_tags": {
+                    "tags": {"key-3": "file_preset"},
+                },
+                "overrides": {"test_override": "original"},
+            },
+            "__value__": "test_override",
+            "test_value": "is_overwritten",
+        }
+        yield
+
+
+@pytest.fixture
+def preset_file_invalid_value():
+    with patch("ytdl_sub.subscriptions.subscription.load_yaml") as mock_load_yaml:
+        mock_load_yaml.return_value = {
+            "__value__": {"should be": "string"},
+        }
+        yield
+
+
+@pytest.fixture
+def preset_file_subscription_using_value_when_not_defined():
+    with patch("ytdl_sub.subscriptions.subscription.load_yaml") as mock_load_yaml:
+        mock_load_yaml.return_value = {"sub_name": "single value, __value__ not defined"}
+        yield
+
+
+@pytest.fixture
+def preset_file_subscription_with_invalid_form():
+    with patch("ytdl_sub.subscriptions.subscription.load_yaml") as mock_load_yaml:
+        mock_load_yaml.return_value = {"sub_name": 4332}
+        yield
+
+
+@pytest.mark.usefixtures(preset_file.__name__)
+def test_subscription_file_preset_applies(config_file: ConfigFile):
+    subs = Subscription.from_file_path(config=config_file, subscription_path="mocked")
+    assert len(subs) == 1
+
+    # Test __preset__ worked correctly
+    preset_sub = subs[0]
+    nfo_options: NfoTagsOptions = preset_sub.plugins.get(NfoTagsOptions)
+    tags_string_dict = {
+        key: formatter[0].format_string for key, formatter in nfo_options.tags.string_tags.items()
+    }
+
+    assert tags_string_dict == {
+        "key-1": "preset_0",
+        "key-2": "preset_2",
+        "key-3": "file_preset",
+        "key-4": "test_preset",
     }
 
 
-def test_subscription_file_preset_applies(config_file: ConfigFile, preset_file: Dict):
+@pytest.mark.usefixtures(preset_file_with_value.__name__)
-    with patch("ytdl_sub.subscriptions.subscription.load_yaml") as mock_load_yaml:
+def test_subscription_file_value_applies(config_file: ConfigFile):
-        mock_load_yaml.return_value = preset_file
+    subs = Subscription.from_file_path(config=config_file, subscription_path="mocked")
+    assert len(subs) == 1
 
-        subs = Subscription.from_file_path(config=config_file, subscription_path="mocked")
+    # Test __value__ worked correctly
-        assert len(subs) == 1
+    value_sub = subs[0]
+    assert value_sub.overrides.dict_with_format_strings.get("test_override") == "is_overwritten"
 
-        nfo_options: NfoTagsOptions = subs[0].plugins.get(NfoTagsOptions)
-        tags_string_dict = {
-            key: formatter[0].format_string
-            for key, formatter in nfo_options.tags.string_tags.items()
-        }
 
-        assert tags_string_dict == {
+@pytest.mark.usefixtures(preset_file_invalid_value.__name__)
-            "key-1": "preset_0",
+def test_subscription_file_bad_value(config_file: ConfigFile):
-            "key-2": "preset_2",
+    with pytest.raises(
-            "key-3": "file_preset",
+        ValidationException,
-            "key-4": "test_preset",
+        match=re.escape(
-        }
+            f"Using {FILE_SUBSCRIPTION_VALUE_KEY} in a subscription"
+            f"must be a string that corresponds to an override variable"
+        ),
+    ):
+        _ = Subscription.from_file_path(config=config_file, subscription_path="mocked")
+
+
+@pytest.mark.usefixtures(preset_file_subscription_using_value_when_not_defined.__name__)
+def test_subscription_file_using_value_when_not_defined(config_file: ConfigFile):
+    with pytest.raises(
+        ValidationException,
+        match=re.escape(
+            f"Subscription sub_name is a string, but "
+            f"{FILE_SUBSCRIPTION_VALUE_KEY} is not set to an override variable"
+        ),
+    ):
+        _ = Subscription.from_file_path(config=config_file, subscription_path="mocked")
+
+
+@pytest.mark.usefixtures(preset_file_subscription_with_invalid_form.__name__)
+def test_subscription_file_invalid_form(config_file: ConfigFile):
+    with pytest.raises(
+        ValidationException,
+        match=re.escape(f"Subscription sub_name should be in the form of a preset"),
+    ):
+        _ = Subscription.from_file_path(config=config_file, subscription_path="mocked")