Add `uv add --no-sync` and `uv remove --no-sync` (#5881)

## Summary

Closes https://github.com/astral-sh/uv/issues/5867.

crates/uv-cli/src/lib.rs

@@ -2304,6 +2304,10 @@ pub struct AddArgs {
     #[arg(long)]
     pub extra: Option<Vec<ExtraName>>,
 
+    /// Avoid syncing the virtual environment after re-locking the project.
+    #[arg(long, conflicts_with = "frozen")]
+    pub no_sync: bool,
+
     /// Assert that the `uv.lock` will remain unchanged.
     #[arg(long, conflicts_with = "frozen")]
     pub locked: bool,
@@ -2354,6 +2358,10 @@ pub struct RemoveArgs {
     #[arg(long, conflicts_with("dev"))]
     pub optional: Option<ExtraName>,
 
+    /// Avoid syncing the virtual environment after re-locking the project.
+    #[arg(long, conflicts_with = "frozen")]
+    pub no_sync: bool,
+
     /// Assert that the `uv.lock` will remain unchanged.
     #[arg(long, conflicts_with = "frozen")]
     pub locked: bool,

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

@@ -37,6 +37,7 @@ use crate::settings::ResolverInstallerSettings;
 pub(crate) async fn add(
     locked: bool,
     frozen: bool,
+    no_sync: bool,
     requirements: Vec<RequirementsSource>,
     editable: Option<bool>,
     dependency_type: DependencyType,
@@ -364,6 +365,10 @@ pub(crate) async fn add(
         }
     }
 
+    if no_sync {
+        return Ok(ExitStatus::Success);
+    }
+
     // Sync the environment.
     let (extras, dev) = match dependency_type {
         DependencyType::Production => {

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

@@ -17,9 +17,11 @@ use crate::printer::Printer;
 use crate::settings::ResolverInstallerSettings;
 
 /// Remove one or more packages from the project requirements.
+#[allow(clippy::fn_params_excessive_bools)]
 pub(crate) async fn remove(
     locked: bool,
     frozen: bool,
+    no_sync: bool,
     requirements: Vec<PackageName>,
     dependency_type: DependencyType,
     package: Option<PackageName>,
@@ -120,6 +122,10 @@ pub(crate) async fn remove(
     )
     .await?;
 
+    if no_sync {
+        return Ok(ExitStatus::Success);
+    }
+
     // Perform a full sync, because we don't know what exactly is affected by the removal.
     // TODO(ibraheem): Should we accept CLI overrides for this? Should we even sync here?
     let extras = ExtrasSpecification::All;

crates/uv/src/lib.rs

@@ -1068,6 +1068,7 @@ async fn run_project(
             commands::add(
                 args.locked,
                 args.frozen,
+                args.no_sync,
                 args.requirements,
                 args.editable,
                 args.dependency_type,
@@ -1103,6 +1104,7 @@ async fn run_project(
             commands::remove(
                 args.locked,
                 args.frozen,
+                args.no_sync,
                 args.requirements,
                 args.dependency_type,
                 args.package,

crates/uv/src/settings.rs

@@ -639,6 +639,7 @@ impl LockSettings {
 pub(crate) struct AddSettings {
     pub(crate) locked: bool,
     pub(crate) frozen: bool,
+    pub(crate) no_sync: bool,
     pub(crate) requirements: Vec<RequirementsSource>,
     pub(crate) dependency_type: DependencyType,
     pub(crate) editable: Option<bool>,
@@ -668,6 +669,7 @@ impl AddSettings {
             rev,
             tag,
             branch,
+            no_sync,
             locked,
             frozen,
             installer,
@@ -693,6 +695,7 @@ impl AddSettings {
         Self {
             locked,
             frozen,
+            no_sync,
             requirements,
             dependency_type,
             raw_sources,
@@ -718,6 +721,7 @@ impl AddSettings {
 pub(crate) struct RemoveSettings {
     pub(crate) locked: bool,
     pub(crate) frozen: bool,
+    pub(crate) no_sync: bool,
     pub(crate) requirements: Vec<PackageName>,
     pub(crate) dependency_type: DependencyType,
     pub(crate) package: Option<PackageName>,
@@ -734,6 +738,7 @@ impl RemoveSettings {
             dev,
             optional,
             requirements,
+            no_sync,
             locked,
             frozen,
             installer,
@@ -754,6 +759,7 @@ impl RemoveSettings {
         Self {
             locked,
             frozen,
+            no_sync,
             requirements,
             dependency_type,
             package,

crates/uv/tests/edit.rs

@@ -2136,6 +2136,55 @@ fn add_frozen() -> Result<()> {
     Ok(())
 }
 
+/// Add a requirement without updating the environment.
+#[test]
+fn add_no_sync() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(indoc! {r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        # ...
+        requires-python = ">=3.12"
+        dependencies = []
+    "#})?;
+
+    uv_snapshot!(context.filters(), context.add(&["anyio==3.7.0"]).arg("--no-sync"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    warning: `uv add` is experimental and may change without warning
+    Resolved 4 packages in [TIME]
+    "###);
+
+    let pyproject_toml = fs_err::read_to_string(context.temp_dir.join("pyproject.toml"))?;
+
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(
+            pyproject_toml, @r###"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        # ...
+        requires-python = ">=3.12"
+        dependencies = [
+            "anyio==3.7.0",
+        ]
+        "###
+        );
+    });
+
+    assert!(context.temp_dir.join("uv.lock").exists());
+
+    Ok(())
+}
+
 #[test]
 fn add_reject_multiple_git_ref_flags() {
     let context = TestContext::new("3.12");