feat(settings): add user settings support with defaults values (fix #235)

copier/errors.py

@@ -139,3 +139,7 @@ class DirtyLocalWarning(UserWarning, CopierWarning):
 
 class ShallowCloneWarning(UserWarning, CopierWarning):
     """The template repository is a shallow clone."""
+
+
+class MissingSettingsWarning(UserWarning, CopierWarning):
+    """Settings path has been defined but file is missing."""

copier/main.py

@@ -46,6 +46,7 @@ from .errors import (
     YieldTagInFileError,
 )
 from .jinja_ext import YieldEnvironment, YieldExtension
+from .settings import Settings
 from .subproject import Subproject
 from .template import Task, Template
 from .tools import (
@@ -58,13 +59,7 @@ from .tools import (
     scantree,
     set_git_alternates,
 )
-from .types import (
+from .types import MISSING, AnyByStrDict, JSONSerializable, RelativePath, StrOrPath
-    MISSING,
-    AnyByStrDict,
-    JSONSerializable,
-    RelativePath,
-    StrOrPath,
-)
 from .user_data import DEFAULT_DATA, AnswersMap, Question
 from .vcs import get_git
 
@@ -192,6 +187,7 @@ class Worker:
     answers_file: RelativePath | None = None
     vcs_ref: str | None = None
     data: AnyByStrDict = field(default_factory=dict)
+    settings: Settings = field(default_factory=Settings.from_file)
     exclude: Sequence[str] = ()
     use_prereleases: bool = False
     skip_if_exists: Sequence[str] = ()
@@ -467,6 +463,7 @@ class Worker:
             question = Question(
                 answers=result,
                 jinja_env=self.jinja_env,
+                settings=self.settings,
                 var_name=var_name,
                 **details,
             )
@@ -998,11 +995,14 @@ class Worker:
         )
         subproject_subdir = self.subproject.local_abspath.relative_to(subproject_top)
 
-        with TemporaryDirectory(
+        with (
-            prefix=f"{__name__}.old_copy.",
+            TemporaryDirectory(
-        ) as old_copy, TemporaryDirectory(
+                prefix=f"{__name__}.old_copy.",
-            prefix=f"{__name__}.new_copy.",
+            ) as old_copy,
-        ) as new_copy:
+            TemporaryDirectory(
+                prefix=f"{__name__}.new_copy.",
+            ) as new_copy,
+        ):
             # Copy old template into a temporary destination
             with replace(
                 self,

copier/settings.py

@@ -0,0 +1,40 @@
+"""User settings models and helper functions."""
+
+from __future__ import annotations
+
+import os
+import warnings
+from pathlib import Path
+from typing import Any
+
+import yaml
+from platformdirs import user_config_path
+from pydantic import BaseModel, Field
+
+from .errors import MissingSettingsWarning
+
+ENV_VAR = "COPIER_SETTINGS_PATH"
+
+
+class Settings(BaseModel):
+    """User settings model."""
+
+    defaults: dict[str, Any] = Field(default_factory=dict)
+
+    @classmethod
+    def from_file(cls, settings_path: Path | None = None) -> Settings:
+        """Load settings from a file."""
+        env_path = os.getenv(ENV_VAR)
+        if settings_path is None:
+            if env_path:
+                settings_path = Path(env_path)
+            else:
+                settings_path = user_config_path("copier") / "settings.yml"
+        if settings_path.is_file():
+            data = yaml.safe_load(settings_path.read_text())
+            return cls.model_validate(data)
+        elif env_path:
+            warnings.warn(
+                f"Settings file not found at {env_path}", MissingSettingsWarning
+            )
+        return cls()

copier/user_data.py

@@ -23,6 +23,8 @@ from pydantic_core.core_schema import ValidationInfo
 from pygments.lexers.data import JsonLexer, YamlLexer
 from questionary.prompts.common import Choice
 
+from copier.settings import Settings
+
 from .errors import InvalidTypeError, UserMessageError
 from .tools import cast_to_bool, cast_to_str, force_str_end
 from .types import MISSING, AnyByStrDict, MissingType, OptStrOrPath, StrOrPath
@@ -178,6 +180,7 @@ class Question:
     var_name: str
     answers: AnswersMap
     jinja_env: SandboxedEnvironment
+    settings: Settings = field(default_factory=Settings)
     choices: Sequence[Any] | dict[Any, Any] | str = field(default_factory=list)
     multiselect: bool = False
     default: Any = MISSING
@@ -246,7 +249,9 @@ class Question:
                 except KeyError:
                     if self.default is MISSING:
                         return MISSING
-                    result = self.render_value(self.default)
+                    result = self.render_value(
+                        self.settings.defaults.get(self.var_name, self.default)
+                    )
         result = self.cast_answer(result)
         return result
 

docs/reference/settings.md

@@ -0,0 +1 @@
+::: copier.settings

docs/settings.md

@@ -0,0 +1,39 @@
+# Settings
+
+Copier settings are stored in `<CONFIG_ROOT>/settings.yml` where `<CONFIG_ROOT>` is the
+standard configuration directory for your platform:
+
+-   `$XDG_CONFIG_HOME/copier` (`~/.config/copier ` in most cases) on Linux as defined by
+    [XDG Base Directory Specifications](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html)
+-   `~/Library/Application Support/copier` on macOS as defined by
+    [Apple File System Basics](https://developer.apple.com/library/archive/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/FileSystemOverview/FileSystemOverview.html)
+-   `%USERPROFILE%\AppData\Local\copier` on Windows as defined in
+    [Known folders](https://docs.microsoft.com/en-us/windows/win32/shell/known-folders)
+
+This location can be overridden by setting the `COPIER_SETTINGS_PATH` environment
+variable.
+
+## User defaults
+
+Users may define some reusable default variables in the `defaults` section of the
+configuration file.
+
+```yaml title="<CONFIG_ROOT>/settings.yml"
+defaults:
+    user_name: "John Doe"
+    user_email: john.doe@acme.com
+```
+
+This user data will replace the default value of fields of the same name.
+
+### Well-known variables
+
+To ensure templates efficiently reuse user-defined variables, we invite template authors
+to use the following well-known variables:
+
+| Variable name | Type  | Description            |
+| ------------- | ----- | ---------------------- |
+| `user_name`   | `str` | User's full name       |
+| `user_email`  | `str` | User's email address   |
+| `github_user` | `str` | User's GitHub username |
+| `gitlab_user` | `str` | User's GitLab username |

mkdocs.yml

@@ -11,11 +11,13 @@ nav:
   - Configuring a template: "configuring.md"
   - Generating a project: "generating.md"
   - Updating a project: "updating.md"
+  - Settings: "settings.md"
   - Reference:
       - cli.py: "reference/cli.md"
       - errors.py: "reference/errors.md"
       - jinja_ext.py: "reference/jinja_ext.md"
       - main.py: "reference/main.md"
+      - settings.py: "reference/settings.md"
       - subproject.py: "reference/subproject.md"
       - template.py: "reference/template.md"
       - tools.py: "reference/tools.md"

poetry.lock

@@ -1755,4 +1755,4 @@ type = ["pytest-mypy"]
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.9"
-content-hash = "888edb00b45adbcefa12e5e242365976d18e2f7356d522b873e973debbb59517"
+content-hash = "3c9bb33fa0a43bd04125dbd879cef233ac4e3582431b3e06817f77bc9da84920"

pyproject.toml

@@ -41,6 +41,7 @@ pygments = ">=2.7.1"
 pyyaml = ">=5.3.1"
 questionary = ">=1.8.1"
 eval-type-backport = { version = ">=0.1.3,<0.3.0", python = "<3.10" }
+platformdirs = ">=4.3.6"
 
 [tool.poetry.group.dev]
 optional = true

tests/conftest.py

@@ -2,7 +2,9 @@ from __future__ import annotations
 
 import platform
 import sys
+from pathlib import Path
 from typing import Any, Iterator
+from unittest.mock import patch
 
 import pytest
 from coverage.tracer import CTracer
@@ -75,3 +77,18 @@ def gitconfig(gitconfig: GitConfig) -> Iterator[GitConfig]:
     """
     with local.env(GIT_CONFIG_GLOBAL=str(gitconfig)):
         yield gitconfig
+
+
+@pytest.fixture
+def config_path(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> Iterator[Path]:
+    config_path = tmp_path / "config"
+    monkeypatch.delenv("COPIER_SETTINGS_PATH", raising=False)
+    with patch("copier.settings.user_config_path", return_value=config_path):
+        yield config_path
+
+
+@pytest.fixture
+def settings_path(config_path: Path) -> Path:
+    config_path.mkdir()
+    settings_path = config_path / "settings.yml"
+    return settings_path

tests/test_config.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import json
 from pathlib import Path
 from textwrap import dedent
 from typing import Any, Callable
@@ -91,6 +92,59 @@ def test_read_data(
     )
 
 
+def test_settings_defaults_precedence(
+    tmp_path_factory: pytest.TempPathFactory, settings_path: Path
+) -> None:
+    src, dst = map(tmp_path_factory.mktemp, ("src", "dst"))
+    build_file_tree(
+        {
+            (src / "copier.yml"): (
+                f"""\
+                # This is a comment
+                _envops: {BRACKET_ENVOPS_JSON}
+                a_string: lorem ipsum
+                a_number: 12345
+                a_boolean: true
+                a_list:
+                    - one
+                    - two
+                    - three
+                """
+            ),
+            (src / "user_data.txt.jinja"): (
+                """\
+                A string: [[ a_string ]]
+                A number: [[ a_number ]]
+                A boolean: [[ a_boolean ]]
+                A list: [[ ", ".join(a_list) ]]
+                """
+            ),
+        }
+    )
+    settings_path.write_text(
+        dedent(
+            """\
+        defaults:
+            a_string: whatever
+            a_number: 42
+            a_boolean: false
+            a_list:
+                - one
+                - two
+    """
+        )
+    )
+    copier.run_copy(str(src), dst, defaults=True, overwrite=True)
+    assert (dst / "user_data.txt").read_text() == dedent(
+        """\
+        A string: whatever
+        A number: 42
+        A boolean: False
+        A list: one, two
+        """
+    )
+
+
 def test_invalid_yaml(capsys: pytest.CaptureFixture[str]) -> None:
     conf_path = Path("tests", "demo_invalid", "copier.yml")
     with pytest.raises(InvalidConfigFileError):
@@ -445,6 +499,7 @@ def test_user_defaults(
         "user_defaults_updated",
         "data_initial",
         "data_updated",
+        "settings_defaults",
         "expected_initial",
         "expected_updated",
     ),
@@ -460,6 +515,53 @@ def test_user_defaults(
             },
             {},
             {},
+            {},
+            dedent(
+                """\
+                A string: foo
+                """
+            ),
+            dedent(
+                """\
+                A string: foo
+                """
+            ),
+        ),
+        # Settings defaults takes precedence over initial defaults.
+        # The output should remain unchanged following the update operation.
+        (
+            {},
+            {},
+            {},
+            {},
+            {
+                "a_string": "bar",
+            },
+            dedent(
+                """\
+                A string: bar
+                """
+            ),
+            dedent(
+                """\
+                A string: bar
+                """
+            ),
+        ),
+        # User provided defaults takes precedence over initial defaults and settings defaults.
+        # The output should remain unchanged following the update operation.
+        (
+            {
+                "a_string": "foo",
+            },
+            {
+                "a_string": "foobar",
+            },
+            {},
+            {},
+            {
+                "a_string": "bar",
+            },
             dedent(
                 """\
                 A string: foo
@@ -484,6 +586,9 @@ def test_user_defaults(
                 "a_string": "yosemite",
             },
             {},
+            {
+                "a_string": "bar",
+            },
             dedent(
                 """\
                 A string: yosemite
@@ -510,6 +615,9 @@ def test_user_defaults(
             {
                 "a_string": "red rocks",
             },
+            {
+                "a_string": "bar",
+            },
             dedent(
                 """\
                 A string: yosemite
@@ -529,8 +637,10 @@ def test_user_defaults_updated(
     user_defaults_updated: AnyByStrDict,
     data_initial: AnyByStrDict,
     data_updated: AnyByStrDict,
+    settings_defaults: AnyByStrDict,
     expected_initial: str,
     expected_updated: str,
+    settings_path: Path,
 ) -> None:
     src, dst = map(tmp_path_factory.mktemp, ("src", "dst"))
     with local.cwd(src):
@@ -557,6 +667,7 @@ def test_user_defaults_updated(
             }
         )
         git_init()
+    settings_path.write_text(f"defaults: {json.dumps(settings_defaults)}")
 
     copier.run_copy(
         str(src),

tests/test_settings.py

@@ -0,0 +1,71 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+from copier.errors import MissingSettingsWarning
+from copier.settings import Settings
+
+
+def test_default_settings() -> None:
+    settings = Settings()
+
+    assert settings.defaults == {}
+
+
+def test_settings_from_default_location(settings_path: Path) -> None:
+    settings_path.write_text("defaults:\n  foo: bar")
+
+    settings = Settings.from_file()
+
+    assert settings.defaults == {"foo": "bar"}
+
+
+@pytest.mark.usefixtures("config_path")
+def test_settings_from_default_location_dont_exists() -> None:
+    settings = Settings.from_file()
+
+    assert settings.defaults == {}
+
+
+def test_settings_from_env_location(
+    settings_path: Path, tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    settings_path.write_text("defaults:\n  foo: bar")
+
+    settings_from_env_path = tmp_path / "settings.yml"
+    settings_from_env_path.write_text("defaults:\n  foo: baz")
+
+    monkeypatch.setenv("COPIER_SETTINGS_PATH", str(settings_from_env_path))
+
+    settings = Settings.from_file()
+
+    assert settings.defaults == {"foo": "baz"}
+
+
+def test_settings_from_param(
+    settings_path: Path, tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    settings_path.write_text("defaults:\n  foo: bar")
+
+    settings_from_env_path = tmp_path / "settings.yml"
+    settings_from_env_path.write_text("defaults:\n  foo: baz")
+
+    monkeypatch.setenv("COPIER_SETTINGS_PATH", str(settings_from_env_path))
+
+    file_path = tmp_path / "file.yml"
+    file_path.write_text("defaults:\n  from: file")
+
+    settings = Settings.from_file(file_path)
+
+    assert settings.defaults == {"from": "file"}
+
+
+def test_settings_defined_but_missing(
+    settings_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    monkeypatch.setenv("COPIER_SETTINGS_PATH", str(settings_path))
+
+    with pytest.warns(MissingSettingsWarning):
+        Settings.from_file()