refactor: Create the concept of fetchers

pyproject.toml

@@ -57,22 +57,22 @@ sortedcontainers = "*"
 click = "*"
 # Pin marshmallow to avoid error on "pip install -U nitpick":
 # marshmallow-polyfield 5.7 has requirement marshmallow>=3.0.0b10, but you'll have marshmallow 2.19.5 which is incompatible.
-marshmallow = {version = ">=3.0.0b10"}
+marshmallow = { version = ">=3.0.0b10" }
 # Pin to avoid error on "flake8 ." when there is an invalid TOML style:
 # TypeError: _deserialize() got an unexpected keyword argument 'partial'
 marshmallow-polyfield = "^5.10"
 identify = "*"
 "more-itertools" = "*"
 pluggy = "*"
-pylint = {version = "*", optional = true}
-pytest = {version = "*", optional = true}
-pytest-cov = {version = "*", optional = true}
-testfixtures = {version = "*", optional = true}
-freezegun = {version = "*", optional = true}
-responses = {version = "*", optional = true}
-sphinx = {version = "*", optional = true}
-sphinx_rtd_theme = {version = "*", optional = true}
-sphobjinv = {version = "*", optional = true}
+pylint = { version = "*", optional = true }
+pytest = { version = "*", optional = true }
+pytest-cov = { version = "*", optional = true }
+testfixtures = { version = "*", optional = true }
+freezegun = { version = "*", optional = true }
+responses = { version = "*", optional = true }
+sphinx = { version = "*", optional = true }
+sphinx_rtd_theme = { version = "*", optional = true }
+sphobjinv = { version = "*", optional = true }
 pydantic = "*"
 autorepr = "*"
 loguru = "*"

src/nitpick/generic.py

@@ -15,6 +15,8 @@
 from nitpick.constants import DOUBLE_QUOTE, PROJECT_NAME, SEPARATOR_FLATTEN, SEPARATOR_QUOTED_SPLIT, SINGLE_QUOTE
 from nitpick.typedefs import JsonDict, PathOrStr
 
+URL_RE = re.compile(r"[a-z]+://\w+")
+
 
 def get_subclasses(cls):
     """Recursively get subclasses of a parent class."""
@@ -218,8 +220,10 @@ def is_url(url: str) -> bool:
     False
     >>> is_url("http://example.com")
     True
+    >>> is_url("github://andreoliwa/nitpick/styles/black")
+    True
     """
-    return url.startswith("http")
+    return bool(URL_RE.match(url))
 
 
 def relative_to_current_dir(path_or_str: Optional[PathOrStr]) -> str:

src/nitpick/project.py

@@ -3,12 +3,14 @@
 from dataclasses import dataclass
 from functools import lru_cache
 from pathlib import Path
-from typing import Iterable, Iterator, List, Optional, Set
+from typing import Iterable, Iterator, List, Optional, Set, Union
 
 import pluggy
 from autorepr import autorepr
 from loguru import logger
 from marshmallow_polyfield import PolyField
+from more_itertools import peekable
+from more_itertools.more import always_iterable
 from pluggy import PluginManager
 
 from nitpick import fields, plugins
@@ -115,7 +117,7 @@ class Configuration:
     """Configuration read from one of the ``CONFIG_FILES``."""
 
     file: Optional[Path]
-    styles: List[str]
+    styles: Union[str, List[str]]
     cache: str
 
 
@@ -192,7 +194,7 @@ def read_configuration(self) -> Configuration:
         config_dict = search_dict(TOOL_NITPICK_JMEX, toml_format.as_data, {})
         validation_errors = ToolNitpickSectionSchema().validate(config_dict)
         if not validation_errors:
-            return Configuration(config_file, config_dict.get("style", ""), config_dict.get("cache", ""))
+            return Configuration(config_file, config_dict.get("style", []), config_dict.get("cache", ""))
 
         # pylint: disable=import-outside-toplevel
         from nitpick.plugins.info import FileInfo
@@ -213,7 +215,7 @@ def merge_styles(self, offline: bool) -> Iterator[Fuss]:
         from nitpick.style import Style
 
         style = Style(self, offline, config.cache)
-        style_errors = list(style.find_initial_styles(config.styles))
+        style_errors = list(style.find_initial_styles(peekable(always_iterable(config.styles))))
         if style_errors:
             raise QuitComplainingError(style_errors)