Add support for optional --description in uv init (#10209)

## Summary
Closes #7913 by adding an optional `--description` argument to `uv init`
that fills the description field in the pyproject.toml with the supplied
arg value.

Updated `uv init` docs to describe this new optional argument.
<!-- What's the purpose of the change? What does it do, and why? -->

## Test Plan
Added snapshot tests in `uv/crates/uv/tests/it/init.rs` to test this
functionality.
<!-- How was it tested? -->

---------

Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>

crates/uv-cli/src/lib.rs

@@ -2568,9 +2568,13 @@ pub struct InitArgs {
     ///
     /// By default, adds a requirement on the system Python version; use `--python` to specify an
     /// alternative Python version requirement.
-    #[arg(long, conflicts_with_all=["app", "lib", "package", "build_backend"])]
+    #[arg(long, conflicts_with_all=["app", "lib", "package", "build_backend", "description"])]
     pub r#script: bool,
 
+    /// Set the project description.
+    #[arg(long, conflicts_with = "script")]
+    pub description: Option<String>,
+
     /// Initialize a version control system for the project.
     ///
     /// By default, uv will initialize a Git repository (`git`). Use `--vcs none` to explicitly

crates/uv/src/commands/project/init.rs

@@ -41,6 +41,7 @@ pub(crate) async fn init(
     name: Option<PackageName>,
     package: bool,
     init_kind: InitKind,
+    description: Option<String>,
     vcs: Option<VersionControlSystem>,
     build_backend: Option<ProjectBuildBackend>,
     no_readme: bool,
@@ -129,6 +130,7 @@ pub(crate) async fn init(
                 &name,
                 package,
                 project_kind,
+                description,
                 vcs,
                 build_backend,
                 no_readme,
@@ -270,6 +272,7 @@ async fn init_project(
     name: &PackageName,
     package: bool,
     project_kind: InitProjectKind,
+    description: Option<String>,
     vcs: Option<VersionControlSystem>,
     build_backend: Option<ProjectBuildBackend>,
     no_readme: bool,
@@ -564,6 +567,7 @@ async fn init_project(
         name,
         path,
         &requires_python,
+        description.as_deref(),
         vcs,
         build_backend,
         author_from,
@@ -687,6 +691,7 @@ impl InitProjectKind {
         name: &PackageName,
         path: &Path,
         requires_python: &RequiresPython,
+        description: Option<&str>,
         vcs: Option<VersionControlSystem>,
         build_backend: Option<ProjectBuildBackend>,
         author_from: Option<AuthorFrom>,
@@ -698,6 +703,7 @@ impl InitProjectKind {
                 name,
                 path,
                 requires_python,
+                description,
                 vcs,
                 build_backend,
                 author_from,
@@ -708,6 +714,7 @@ impl InitProjectKind {
                 name,
                 path,
                 requires_python,
+                description,
                 vcs,
                 build_backend,
                 author_from,
@@ -722,6 +729,7 @@ impl InitProjectKind {
         name: &PackageName,
         path: &Path,
         requires_python: &RequiresPython,
+        description: Option<&str>,
         vcs: Option<VersionControlSystem>,
         build_backend: Option<ProjectBuildBackend>,
         author_from: Option<AuthorFrom>,
@@ -741,7 +749,13 @@ impl InitProjectKind {
         let author = get_author_info(path, author_from);
 
         // Create the `pyproject.toml`
-        let mut pyproject = pyproject_project(name, requires_python, author.as_ref(), no_readme);
+        let mut pyproject = pyproject_project(
+            name,
+            requires_python,
+            author.as_ref(),
+            description,
+            no_readme,
+        );
 
         // Include additional project configuration for packaged applications
         if package {
@@ -788,6 +802,7 @@ impl InitProjectKind {
         name: &PackageName,
         path: &Path,
         requires_python: &RequiresPython,
+        description: Option<&str>,
         vcs: Option<VersionControlSystem>,
         build_backend: Option<ProjectBuildBackend>,
         author_from: Option<AuthorFrom>,
@@ -803,7 +818,13 @@ impl InitProjectKind {
         let author = get_author_info(path, author_from.unwrap_or_default());
 
         // Create the `pyproject.toml`
-        let mut pyproject = pyproject_project(name, requires_python, author.as_ref(), no_readme);
+        let mut pyproject = pyproject_project(
+            name,
+            requires_python,
+            author.as_ref(),
+            description,
+            no_readme,
+        );
 
         // Always include a build system if the project is packaged.
         let build_backend = build_backend.unwrap_or_default();
@@ -847,19 +868,21 @@ fn pyproject_project(
     name: &PackageName,
     requires_python: &RequiresPython,
     author: Option<&Author>,
+    description: Option<&str>,
     no_readme: bool,
 ) -> String {
     indoc::formatdoc! {r#"
         [project]
         name = "{name}"
         version = "0.1.0"
-        description = "Add your description here"{readme}{authors}
+        description = "{description}"{readme}{authors}
         requires-python = "{requires_python}"
         dependencies = []
     "#,
         readme = if no_readme { "" } else { "\nreadme = \"README.md\"" },
         authors = author.map_or_else(String::new, |author| format!("\nauthors = [\n    {}\n]", author.to_toml_string())),
         requires_python = requires_python.specifiers(),
+        description = description.unwrap_or("Add your description here"),
     }
 }
 

crates/uv/src/lib.rs

@@ -1360,6 +1360,7 @@ async fn run_project(
                 args.name,
                 args.package,
                 args.kind,
+                args.description,
                 args.vcs,
                 args.build_backend,
                 args.no_readme,

crates/uv/src/settings.rs

@@ -189,6 +189,7 @@ pub(crate) struct InitSettings {
     pub(crate) name: Option<PackageName>,
     pub(crate) package: bool,
     pub(crate) kind: InitKind,
+    pub(crate) description: Option<String>,
     pub(crate) vcs: Option<VersionControlSystem>,
     pub(crate) build_backend: Option<ProjectBuildBackend>,
     pub(crate) no_readme: bool,
@@ -212,6 +213,7 @@ impl InitSettings {
             app,
             lib,
             script,
+            description,
             vcs,
             build_backend,
             no_readme,
@@ -241,6 +243,7 @@ impl InitSettings {
             name,
             package,
             kind,
+            description,
             vcs,
             build_backend,
             no_readme,

crates/uv/tests/it/init.rs

@@ -3271,3 +3271,89 @@ fn init_application_package_uv() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn init_with_description() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let child = context.temp_dir.join("foo");
+    fs_err::create_dir_all(&child)?;
+
+    // Initialize the project with a description
+    context
+        .init()
+        .current_dir(&child)
+        .arg("--description")
+        .arg("A sample project description")
+        .arg("--lib")
+        .assert()
+        .success();
+
+    // Read the generated pyproject.toml
+    let pyproject = fs_err::read_to_string(child.join("pyproject.toml"))?;
+
+    // Verify the description in pyproject.toml
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(
+            pyproject, @r#"
+        [project]
+        name = "foo"
+        version = "0.1.0"
+        description = "A sample project description"
+        readme = "README.md"
+        requires-python = ">=3.12"
+        dependencies = []
+
+        [build-system]
+        requires = ["hatchling"]
+        build-backend = "hatchling.build"
+        "#
+        );
+    });
+
+    Ok(())
+}
+
+#[test]
+fn init_without_description() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let child = context.temp_dir.join("bar");
+    fs_err::create_dir_all(&child)?;
+
+    // Initialize the project without a description
+    context
+        .init()
+        .current_dir(&child)
+        .arg("--lib")
+        .assert()
+        .success();
+
+    // Read the generated pyproject.toml
+    let pyproject = fs_err::read_to_string(child.join("pyproject.toml"))?;
+
+    // Verify the default description in pyproject.toml
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(
+            pyproject, @r#"
+        [project]
+        name = "bar"
+        version = "0.1.0"
+        description = "Add your description here"
+        readme = "README.md"
+        requires-python = ">=3.12"
+        dependencies = []
+
+        [build-system]
+        requires = ["hatchling"]
+        build-backend = "hatchling.build"
+        "#
+        );
+    });
+
+    Ok(())
+}

docs/reference/cli.md

@@ -589,6 +589,8 @@ uv init [OPTIONS] [PATH]
 <p>While uv configuration can be included in a <code>pyproject.toml</code> file, it is not allowed in this context.</p>
 
 <p>May also be set with the <code>UV_CONFIG_FILE</code> environment variable.</p>
+</dd><dt><code>--description</code> <i>description</i></dt><dd><p>Set the project description</p>
+
 </dd><dt><code>--directory</code> <i>directory</i></dt><dd><p>Change to the given directory prior to running the command.</p>
 
 <p>Relative paths are resolved with the given directory as the base.</p>