Respect exclusions in uv init (#5318)

## Summary

Avoid adding to the workspace.

Closes #5254.

crates/uv-workspace/src/workspace.rs

@@ -330,6 +330,21 @@ impl Workspace {
         &self.pyproject_toml
     }
 
+    /// Returns `true` if the path is excluded by the workspace.
+    pub fn excludes(&self, project_path: &Path) -> Result<bool, WorkspaceError> {
+        if let Some(workspace) = self
+            .pyproject_toml
+            .tool
+            .as_ref()
+            .and_then(|tool| tool.uv.as_ref())
+            .and_then(|uv| uv.workspace.as_ref())
+        {
+            is_excluded_from_workspace(project_path, &self.install_path, workspace)
+        } else {
+            Ok(false)
+        }
+    }
+
     /// Collect the workspace member projects from the `members` and `excludes` entries.
     async fn collect_members(
         workspace_root: PathBuf,

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

@@ -115,22 +115,32 @@ pub(crate) async fn init(
     }
 
     if let Some(workspace) = workspace {
-        // Add the package to the workspace.
-        let mut pyproject = PyProjectTomlMut::from_toml(workspace.pyproject_toml())?;
-        pyproject.add_workspace(path.strip_prefix(workspace.install_path())?)?;
-
-        // Save the modified `pyproject.toml`.
-        fs_err::write(
-            workspace.install_path().join("pyproject.toml"),
-            pyproject.to_string(),
-        )?;
+        if workspace.excludes(&path)? {
+            // If the member is excluded by the workspace, ignore it.
+            writeln!(
+                printer.stderr(),
+                "Project `{}` is excluded by workspace `{}`",
+                name.cyan(),
+                workspace.install_path().simplified_display().cyan()
+            )?;
+        } else {
+            // Add the package to the workspace.
+            let mut pyproject = PyProjectTomlMut::from_toml(workspace.pyproject_toml())?;
+            pyproject.add_workspace(path.strip_prefix(workspace.install_path())?)?;
+
+            // Save the modified `pyproject.toml`.
+            fs_err::write(
+                workspace.install_path().join("pyproject.toml"),
+                pyproject.to_string(),
+            )?;
 
-        writeln!(
-            printer.stderr(),
-            "Adding `{}` as member of workspace `{}`",
-            name.cyan(),
-            workspace.install_path().simplified_display().cyan()
-        )?;
+            writeln!(
+                printer.stderr(),
+                "Adding `{}` as member of workspace `{}`",
+                name.cyan(),
+                workspace.install_path().simplified_display().cyan()
+            )?;
+        }
     }
 
     match explicit_path {

crates/uv/tests/init.rs

@@ -727,7 +727,7 @@ fn init_virtual_workspace() -> Result<()> {
 
 /// Run `uv init` from within a workspace. The path is already included via `members`.
 #[test]
-fn init_matches_member() -> Result<()> {
+fn init_matches_members() -> Result<()> {
     let context = TestContext::new("3.12");
 
     let pyproject_toml = context.temp_dir.child("pyproject.toml");
@@ -766,3 +766,47 @@ fn init_matches_member() -> Result<()> {
 
     Ok(())
 }
+
+/// Run `uv init` from within a workspace. The path is already included via `members`.
+#[test]
+fn init_matches_exclude() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(indoc! {
+        r"
+        [tool.uv.workspace]
+        exclude = ['packages/foo']
+        members = ['packages/*']
+        ",
+    })?;
+
+    let packages = context.temp_dir.join("packages");
+    fs_err::create_dir_all(packages)?;
+
+    uv_snapshot!(context.filters(), context.init().current_dir(context.temp_dir.join("packages")).arg("foo"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    warning: `uv init` is experimental and may change without warning
+    Project `foo` is excluded by workspace `[TEMP_DIR]/`
+    Initialized project `foo` at `[TEMP_DIR]/packages/foo`
+    "###);
+
+    let workspace = fs_err::read_to_string(context.temp_dir.join("pyproject.toml"))?;
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(
+            workspace, @r###"
+        [tool.uv.workspace]
+        exclude = ['packages/foo']
+        members = ['packages/*']
+        "###
+        );
+    });
+
+    Ok(())
+}