feat: support for configuring dependency constraint strategy (#11)

Add support for configuring dependency constraint strategy

Co-authored-by: Matthew Gamble <[email protected]>

README.md

@@ -47,6 +47,27 @@ the dependency will be rewritten as if it had been defined as:
 b = "^1.2.3"
 ```
 
+## Configuration
+
+You can define a section in your `pyproject.toml` file named `tool.stickywheel`, to configure various options.
+
+### Dependency constraint strategy
+
+The default strategy is `semver` (described in the "Help" section above), but there are other choices:
+
+| strategy  | version | result    |
+|-----------|---------|-----------|
+| `semver`  | `1.2.3` | `^1.2.3`  |
+| `minimum` | `1.2.3` | `>=1.2.3` |
+| `exact`   | `1.2.3` | `1.2.3`   |
+
+To override the default, add `strategy` to the configuration. For example:
+
+```toml
+[tool.stickywheel]
+strategy = "exact"
+```
+
 ## ⚖️ Licence
 
 This project is licensed under the [MIT licence][mit_licence].
@@ -61,4 +82,4 @@ This project uses [Semantic Versioning][semvar].
 [discussions]: https://github.com/artisanofcode/poetry-stickywheel-plugin/discussions
 [mit_licence]: http://dan.mit-license.org/
 [cc_by_sa]: https://creativecommons.org/licenses/by-sa/4.0/
-[semvar]: http://semver.org/
+[semvar]: http://semver.org/

src/poetry_stickywheel_plugin.py

@@ -10,22 +10,45 @@
 import poetry.core.packages.dependency
 import poetry.core.packages.dependency_group
 import poetry.core.packages.directory_dependency
+import poetry.core.pyproject.exceptions
 import poetry.core.pyproject.toml
 import poetry.plugins.application_plugin
 
 
+class StickyWheelsConfig:
+    def __init__(self, config: poetry.core.pyproject.toml.PyProjectTOML) -> None:
+        self._config = config.data.get("tool", {}).get("stickywheel", {})
+
+    @property
+    def strategy(self) -> str:
+        return self._config.get("strategy", "semver")
+
+    def prepare_constraint(self, version: str) -> str:
+        if self.strategy == "semver":
+            return f"^{version}"
+        elif self.strategy == "minimum":
+            return f">={version}"
+        elif self.strategy == "exact":
+            return version
+        else:
+            raise poetry.core.pyproject.exceptions.PyProjectException(
+                "Invalid StickyWheel strategy configured."
+            )
+
+
 class StickyWheelsPlugin(poetry.plugins.application_plugin.ApplicationPlugin):
     COMMANDS = (
         poetry.console.commands.build.BuildCommand,
         poetry.console.commands.publish.PublishCommand,
     )
 
-    def activate(self, application: poetry.console.application.Application):
+    def activate(self, application: poetry.console.application.Application) -> None:
         application.event_dispatcher.add_listener(
             cleo.events.console_events.COMMAND,
             self.event_listener,
         )
         self.package = application.poetry.package
+        self.config = StickyWheelsConfig(application.poetry.pyproject)
 
     def event_listener(
         self,
@@ -87,6 +110,6 @@ def pin_dependency(
 
         return poetry.core.packages.dependency.Dependency(
             name,
-            f"^{version}",
+            self.config.prepare_constraint(version),
             groups=dependency.groups,
         )