Create Config.annotations_for_path

Signed-off-by: Carmen Bianca BAKKER <carmenbianca@fsfe.org>

src/reuse/_config.py

@@ -6,6 +6,8 @@
 
 from dataclasses import dataclass, field
 from gettext import gettext as _
+from os import PathLike
+from pathlib import Path, PurePath
 from typing import Any, Dict, Optional
 
 import yaml
@@ -19,6 +21,17 @@ class AnnotateOptions:
     contact: Optional[str] = None
     license: Optional[str] = None
 
+    def merge(self, other: "AnnotateOptions") -> "AnnotateOptions":
+        """Return a copy of *self*, but replace attributes with truthy
+        attributes of *other*.
+        """
+        new_kwargs = {}
+        for key, value in self.__dict__.items():
+            if other_value := getattr(other, key):
+                value = other_value
+            new_kwargs[key] = value
+        return self.__class__(**new_kwargs)
+
 
 @dataclass
 class Config:
@@ -68,6 +81,19 @@ def from_yaml(cls, text: str) -> "Config":
         """
         return cls.from_dict(yaml.load(text, Loader=yaml.Loader))
 
+    # TODO: We could probably smartly cache the results somehow.
+    def annotations_for_path(self, path: PathLike) -> AnnotateOptions:
+        """TODO: Document the precise behaviour."""
+        path = PurePath(path)
+        result = self.global_annotate_options
+        # This assumes that the override options are ordered by reverse
+        # precedence.
+        for o_path, options in self.override_annotate_options.items():
+            o_path = Path(o_path).expanduser()
+            if path.is_relative_to(o_path):
+                result = result.merge(options)
+        return result
+
 
 def _annotate_options_from_dict(value: Dict[str, str]) -> AnnotateOptions:
     return AnnotateOptions(

tests/test_config.py

@@ -4,13 +4,50 @@
 
 """Tests for some _config."""
 
+import os
 from inspect import cleandoc
+from textwrap import indent
+from unittest import mock
 
-from reuse._config import Config
+from reuse._config import AnnotateOptions, Config
 
 # REUSE-IgnoreStart
 
 
+def test_annotate_options_merge_one():
+    """Replace one attribute."""
+    first = AnnotateOptions(
+        name="Jane Doe", contact="jane@example.com", license="MIT"
+    )
+    second = AnnotateOptions(name="John Doe")
+    result = first.merge(second)
+    assert result.name == second.name
+    assert result.contact == first.contact
+    assert result.license == first.license
+
+
+def test_annotate_options_merge_nothing():
+    """When merging with an empty AnnotateOptions, do nothing."""
+    first = AnnotateOptions(
+        name="Jane Doe", contact="jane@example.com", license="MIT"
+    )
+    second = AnnotateOptions()
+    result = first.merge(second)
+    assert result == first
+
+
+def test_annotate_options_merge_all():
+    """When merging with a full AnnotateOptions, replace all attributes."""
+    first = AnnotateOptions(
+        name="Jane Doe", contact="jane@example.com", license="MIT"
+    )
+    second = AnnotateOptions(
+        name="John Doe", contact="john@example.com", license="0BSD"
+    )
+    result = first.merge(second)
+    assert result == second
+
+
 def test_config_from_dict_global_simple():
     """A simple test case for Config.from_dict."""
     value = {
@@ -87,4 +124,91 @@ def test_config_from_yaml_simple():
     )
 
 
+def test_config_from_yaml_ordered():
+    """The override options are ordered by appearance in the yaml file."""
+    overrides = []
+    for i in range(100):
+        overrides.append(
+            indent(
+                cleandoc(
+                    f"""
+                    - path: "{i}"
+                      default_name: Jane Doe
+                    """
+                ),
+                prefix=" " * 4,
+            )
+        )
+    text = cleandoc(
+        """
+        annotate:
+          overrides:
+        {}
+        """
+    ).format("\n".join(overrides))
+    result = Config.from_yaml(text)
+    for i, path in enumerate(result.override_annotate_options):
+        assert str(i) == path
+
+
+def test_annotations_for_path_global():
+    """When there are no overrides, the annotate options for a given path are
+    always the global options.
+    """
+    options = AnnotateOptions(name="Jane Doe")
+    config = Config(global_annotate_options=options)
+    result = config.annotations_for_path("foo")
+    assert result == options == config.global_annotate_options
+
+
+def test_annotations_for_path_no_match():
+    """When the given path doesn't match any overrides, return the global
+    options.
+    """
+    global_options = AnnotateOptions(name="Jane Doe")
+    override_options = AnnotateOptions(name="John Doe")
+    config = Config(
+        global_annotate_options=global_options,
+        override_annotate_options={"~/Projects": override_options},
+    )
+    result = config.annotations_for_path("/etc/foo")
+    assert result == global_options
+
+
+def test_annotations_for_path_one_match():
+    """If one override matches, return the global options merged with the
+    override options.
+    """
+    global_options = AnnotateOptions(name="Jane Doe")
+    override_options = AnnotateOptions(contact="jane@example.com")
+    config = Config(
+        global_annotate_options=global_options,
+        override_annotate_options={"/home/jane/Projects": override_options},
+    )
+    result = config.annotations_for_path(
+        "/home/jane/Projects/reuse-tool/README.md"
+    )
+    assert result.name == "Jane Doe"
+    assert result.contact == "jane@example.com"
+    assert not result.license
+
+
+def test_annotations_for_path_expand_home():
+    """When the key path of an override starts with '~', expand it when
+    checking.
+    """
+    with mock.patch.dict(os.environ, {"HOME": "/home/jane"}):
+        global_options = AnnotateOptions(name="Jane Doe")
+        override_options = AnnotateOptions(contact="jane@example.com")
+        config = Config(
+            global_annotate_options=global_options,
+            override_annotate_options={"~/Projects": override_options},
+        )
+        result = config.annotations_for_path(
+            # This path must be manually expanded and cannot start with a '~'.
+            "/home/jane/Projects/reuse-tool/README.md"
+        )
+        assert result.contact == "jane@example.com"
+
+
 # REUSE-IgnoreEnd