feat: preserve existing data in [project]

CHANGELOG.md

@@ -1,5 +1,17 @@
 # Changelog
 
+## Unreleased
+
+Existing data in `[project]` section of `pyproject.toml` is now preserved by default when migrating. If you prefer that the section is fully replaced, this can be done by setting `--replace-project-section` flag, like so:
+
+```bash
+migrate-to-uv --replace-project-section
+```
+
+### Features
+
+* Preserve existing data in `[project]` section of `pyproject.toml` when migrating ([#84](https://github.com/mkniewallner/migrate-to-uv/pull/84))
+
 ## 0.5.0 - 2025-01-18
 
 ### Features

docs/usage-and-configuration.md

@@ -66,6 +66,17 @@ constraints.
 migrate-to-uv --ignore-locked-versions
 ```
 
+#### `--replace-project-section`
+
+By default, existing data in `[project]` section of `pyproject.toml` is preserved when migrating. This flag allows
+completely replacing existing content.
+
+**Example**:
+
+```bash
+migrate-to-uv --replace-project-section
+```
+
 #### `--package-manager`
 
 By default, `migrate-to-uv` tries to auto-detect the package manager based on the files (and their content) used by the

src/cli.rs

@@ -41,6 +41,11 @@ struct Cli {
         help = "Ignore current locked versions of dependencies when generating `uv.lock`"
     )]
     ignore_locked_versions: bool,
+    #[arg(
+        long,
+        help = "Replace existing data in `[project]` section of `pyproject.toml` instead of keeping existing fields"
+    )]
+    replace_project_section: bool,
     #[arg(
         long,
         help = "Enforce a specific package manager instead of auto-detecting it"
@@ -72,6 +77,7 @@ pub fn cli() {
         dry_run: cli.dry_run,
         skip_lock: cli.skip_lock,
         ignore_locked_versions: cli.ignore_locked_versions,
+        replace_project_section: cli.replace_project_section,
         keep_old_metadata: cli.keep_current_data,
         dependency_groups_strategy: cli.dependency_groups_strategy,
     };

src/converters/mod.rs

@@ -1,4 +1,5 @@
 use crate::converters::pyproject_updater::PyprojectUpdater;
+use crate::schema::pep_621::Project;
 use crate::schema::pyproject::DependencyGroupSpecification;
 use indexmap::IndexMap;
 use log::{error, info, warn};
@@ -30,6 +31,7 @@ pub struct ConverterOptions {
     pub dry_run: bool,
     pub skip_lock: bool,
     pub ignore_locked_versions: bool,
+    pub replace_project_section: bool,
     pub keep_old_metadata: bool,
     pub dependency_groups_strategy: DependencyGroupsStrategy,
 }
@@ -74,6 +76,40 @@ pub trait Converter: Debug {
     /// Build `pyproject.toml` for uv package manager based on current package manager data.
     fn build_uv_pyproject(&self) -> String;
 
+    /// Build PEP 621 `[project]` section, keeping existing fields if the section is already
+    /// defined, unless user has chosen to replace existing section.
+    fn build_project(&self, current_project: Option<Project>, project: Project) -> Project {
+        if self.replace_project_section() {
+            return project;
+        }
+
+        let Some(current_project) = current_project else {
+            return project;
+        };
+
+        Project {
+            name: current_project.name.or(project.name),
+            version: current_project.version.or(project.version),
+            description: current_project.description.or(project.description),
+            authors: current_project.authors.or(project.authors),
+            requires_python: current_project.requires_python.or(project.requires_python),
+            readme: current_project.readme.or(project.readme),
+            license: current_project.license.or(project.license),
+            maintainers: current_project.maintainers.or(project.maintainers),
+            keywords: current_project.keywords.or(project.keywords),
+            classifiers: current_project.classifiers.or(project.classifiers),
+            dependencies: current_project.dependencies.or(project.dependencies),
+            optional_dependencies: current_project
+                .optional_dependencies
+                .or(project.optional_dependencies),
+            urls: current_project.urls.or(project.urls),
+            scripts: current_project.scripts.or(project.scripts),
+            gui_scripts: current_project.gui_scripts.or(project.gui_scripts),
+            entry_points: current_project.entry_points.or(project.entry_points),
+            remaining_fields: current_project.remaining_fields,
+        }
+    }
+
     /// Name of the current package manager.
     fn get_package_manager_name(&self) -> String;
 
@@ -97,6 +133,12 @@ pub trait Converter: Debug {
         self.get_converter_options().skip_lock
     }
 
+    /// Whether to replace existing `[project]` section of `pyproject.toml`, or to keep existing
+    /// fields.
+    fn replace_project_section(&self) -> bool {
+        self.get_converter_options().replace_project_section
+    }
+
     /// Whether to keep current package manager data at the end of the migration.
     fn keep_old_metadata(&self) -> bool {
         self.get_converter_options().keep_old_metadata

src/converters/pip/mod.rs

@@ -1,11 +1,10 @@
 mod dependencies;
 
-use crate::converters::pip::dependencies::get;
 use crate::converters::pyproject_updater::PyprojectUpdater;
 use crate::converters::Converter;
 use crate::converters::ConverterOptions;
 use crate::schema::pep_621::Project;
-use crate::schema::pyproject::DependencyGroupSpecification;
+use crate::schema::pyproject::{DependencyGroupSpecification, PyProject};
 use crate::schema::uv::Uv;
 use crate::toml::PyprojectPrettyFormatter;
 use indexmap::IndexMap;
@@ -26,6 +25,10 @@ pub struct Pip {
 
 impl Converter for Pip {
     fn build_uv_pyproject(&self) -> String {
+        let pyproject_toml_content =
+            fs::read_to_string(self.get_project_path().join("pyproject.toml")).unwrap_or_default();
+        let pyproject: PyProject = toml::from_str(pyproject_toml_content.as_str()).unwrap();
+
         let dev_dependencies = dependencies::get(
             &self.get_project_path(),
             self.dev_requirements_files.clone(),
@@ -73,7 +76,7 @@ impl Converter for Pip {
             pyproject: &mut updated_pyproject,
         };
 
-        pyproject_updater.insert_pep_621(&project);
+        pyproject_updater.insert_pep_621(&self.build_project(pyproject.project, project));
         pyproject_updater.insert_dependency_groups(dependency_groups.as_ref());
         pyproject_updater.insert_uv(&uv);
 
@@ -126,7 +129,7 @@ impl Converter for Pip {
             return None;
         }
 
-        if let Some(dependencies) = get(
+        if let Some(dependencies) = dependencies::get(
             self.get_project_path().as_path(),
             self.requirements_files
                 .clone()

src/converters/pipenv/mod.rs

@@ -7,6 +7,7 @@ use crate::converters::Converter;
 use crate::converters::ConverterOptions;
 use crate::schema::pep_621::Project;
 use crate::schema::pipenv::{PipenvLock, Pipfile};
+use crate::schema::pyproject::PyProject;
 use crate::schema::uv::{SourceContainer, Uv};
 use crate::toml::PyprojectPrettyFormatter;
 use indexmap::IndexMap;
@@ -26,6 +27,10 @@ pub struct Pipenv {
 
 impl Converter for Pipenv {
     fn build_uv_pyproject(&self) -> String {
+        let pyproject_toml_content =
+            fs::read_to_string(self.get_project_path().join("pyproject.toml")).unwrap_or_default();
+        let pyproject: PyProject = toml::from_str(pyproject_toml_content.as_str()).unwrap();
+
         let pipfile_content = fs::read_to_string(self.get_project_path().join("Pipfile")).unwrap();
         let pipfile: Pipfile = toml::from_str(pipfile_content.as_str()).unwrap();
 
@@ -66,7 +71,7 @@ impl Converter for Pipenv {
             pyproject: &mut updated_pyproject,
         };
 
-        pyproject_updater.insert_pep_621(&project);
+        pyproject_updater.insert_pep_621(&self.build_project(pyproject.project, project));
         pyproject_updater.insert_dependency_groups(dependency_groups.as_ref());
         pyproject_updater.insert_uv(&uv);
 
@@ -156,6 +161,7 @@ mod tests {
                 dry_run: true,
                 skip_lock: true,
                 ignore_locked_versions: true,
+                replace_project_section: false,
                 keep_old_metadata: false,
                 dependency_groups_strategy: DependencyGroupsStrategy::SetDefaultGroups,
             },
@@ -188,6 +194,7 @@ mod tests {
                 dry_run: true,
                 skip_lock: true,
                 ignore_locked_versions: true,
+                replace_project_section: false,
                 keep_old_metadata: false,
                 dependency_groups_strategy: DependencyGroupsStrategy::SetDefaultGroups,
             },

src/converters/poetry/mod.rs

@@ -83,6 +83,7 @@ impl Converter for Poetry {
             scripts: project::get_scripts(poetry.scripts, scripts_from_plugins),
             gui_scripts,
             entry_points: poetry_plugins,
+            ..Default::default()
         };
 
         let uv = Uv {
@@ -111,7 +112,7 @@ impl Converter for Poetry {
         pyproject_updater.insert_build_system(
             build_backend::get_new_build_system(pyproject.build_system).as_ref(),
         );
-        pyproject_updater.insert_pep_621(&project);
+        pyproject_updater.insert_pep_621(&self.build_project(pyproject.project, project));
         pyproject_updater.insert_dependency_groups(dependency_groups.as_ref());
         pyproject_updater.insert_uv(&uv);
         pyproject_updater.insert_hatch(hatch.as_ref());
@@ -215,6 +216,7 @@ mod tests {
                 dry_run: true,
                 skip_lock: true,
                 ignore_locked_versions: true,
+                replace_project_section: false,
                 keep_old_metadata: false,
                 dependency_groups_strategy: DependencyGroupsStrategy::SetDefaultGroups,
             },

src/detector.rs

@@ -251,6 +251,7 @@ mod tests {
             dry_run: true,
             skip_lock: true,
             ignore_locked_versions: false,
+            replace_project_section: false,
             keep_old_metadata: false,
             dependency_groups_strategy: DependencyGroupsStrategy::SetDefaultGroups,
         }

src/schema/pep_621.rs

@@ -2,6 +2,8 @@ use crate::schema::poetry::Poetry;
 use crate::schema::uv::Uv;
 use indexmap::IndexMap;
 use serde::{Deserialize, Serialize};
+use serde_json::Value;
+use std::collections::HashMap;
 
 /// <https://packaging.python.org/en/latest/specifications/pyproject-toml/#pyproject-toml-spec>
 #[derive(Default, Deserialize, Serialize)]
@@ -26,6 +28,8 @@ pub struct Project {
     pub gui_scripts: Option<IndexMap<String, String>>,
     #[serde(rename = "entry-points")]
     pub entry_points: Option<IndexMap<String, IndexMap<String, String>>>,
+    #[serde(flatten)]
+    pub remaining_fields: HashMap<String, Value>,
 }
 
 #[derive(Deserialize, Serialize)]

tests/fixtures/pip/existing_project/pyproject.toml

@@ -0,0 +1,4 @@
+[project]
+name = "foobar"
+version = "1.0.0"
+requires-python = ">=3.13"

tests/fixtures/pip/existing_project/requirements.txt

@@ -0,0 +1,19 @@
+# A comment
+anyio==4.7.0
+arrow==1.3.0
+certifi==2024.12.14
+click==8.1.8
+h11==0.14.0
+httpcore==1.0.7
+httpx==0.28.1
+idna==3.10
+markdown-it-py==3.0.0
+mdurl==0.1.2
+pygments==2.18.0
+python-dateutil==2.9.0.post0
+rich==13.9.4
+six==1.17.0
+sniffio==1.3.1
+types-python-dateutil==2.9.0.20241206
+uvicorn @ git+https://github.com/encode/uvicorn
+zstandard==0.23.0

tests/fixtures/pip_tools/existing_project/pyproject.toml

@@ -0,0 +1,4 @@
+[project]
+name = "foobar"
+version = "1.0.0"
+requires-python = ">=3.13"

tests/fixtures/pip_tools/existing_project/requirements.in

@@ -0,0 +1 @@
+arrow>=1.2.3

tests/fixtures/pip_tools/existing_project/requirements.txt

@@ -0,0 +1,12 @@
+#
+# This file is autogenerated by pip-compile with Python 3.13
+# by the following command:
+#
+#    pip-compile requirements.in
+#
+arrow==1.2.3
+    # via -r requirements.in
+python-dateutil==2.7.0
+    # via arrow
+six==1.15.0
+    # via python-dateutil

tests/fixtures/pipenv/existing_project/Pipfile

@@ -0,0 +1,16 @@
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+arrow = ">=1.2.3"
+
+[dev-packages]
+mypy = ">=1.13.0"
+
+[test]
+factory-boy = ">=3.2.1"
+
+[requires]
+python_version = "3.13"

tests/fixtures/pipenv/existing_project/pyproject.toml

@@ -0,0 +1,4 @@
+[project]
+name = "foobar"
+version = "1.0.0"
+requires-python = ">=3.13"

tests/fixtures/poetry/existing_project/pyproject.toml

@@ -0,0 +1,19 @@
+[project]
+name = "foobar"
+version = "1.0.0"
+requires-python = ">=3.13"
+
+[tool.poetry]
+name = "foo"
+version = "0.0.1"
+description = "A description"
+
+[tool.poetry.dependencies]
+python = "^3.11"
+arrow = "^1.2.3"
+
+[tool.poetry.group.dev.dependencies]
+factory-boy = "^3.2.1"
+
+[tool.poetry.group.typing.dependencies]
+mypy = "^1.13.0"