Allow @ references in uv tool install --from (#6842)

## Summary

Closes https://github.com/astral-sh/uv/issues/6796.

crates/uv/src/commands/tool/install.rs

@@ -117,7 +117,7 @@ pub(crate) async fn install(
             .unwrap()
         }
         // Ex) `ruff@0.6.0`
-        Target::Version(name, ref version) => {
+        Target::Version(name, ref version) | Target::FromVersion(_, name, ref version) => {
             if editable {
                 bail!("`--editable` is only supported for local packages");
             }
@@ -136,7 +136,7 @@ pub(crate) async fn install(
             }
         }
         // Ex) `ruff@latest`
-        Target::Latest(name) => {
+        Target::Latest(name) | Target::FromLatest(_, name) => {
             if editable {
                 bail!("`--editable` is only supported for local packages");
             }
@@ -153,7 +153,7 @@ pub(crate) async fn install(
             }
         }
         // Ex) `ruff>=0.6.0`
-        Target::UserDefined(package, from) => {
+        Target::From(package, from) => {
             // Parse the positional name. If the user provided more than a package name, it's an error
             // (e.g., `uv install foo==1.0 --from foo`).
             let Ok(package) = PackageName::from_str(package) else {

crates/uv/src/commands/tool/mod.rs

@@ -22,15 +22,49 @@ pub(crate) enum Target<'a> {
     Version(&'a str, Version),
     /// e.g., `ruff@latest`
     Latest(&'a str),
-    /// e.g., `--from ruff==0.6.0`
+    /// e.g., `ruff --from ruff>=0.6.0`
-    UserDefined(&'a str, &'a str),
+    From(&'a str, &'a str),
+    /// e.g., `ruff --from ruff@0.6.0`
+    FromVersion(&'a str, &'a str, Version),
+    /// e.g., `ruff --from ruff@latest`
+    FromLatest(&'a str, &'a str),
 }
 
 impl<'a> Target<'a> {
     /// Parse a target into a command name and a requirement.
     pub(crate) fn parse(target: &'a str, from: Option<&'a str>) -> Self {
         if let Some(from) = from {
-            return Self::UserDefined(target, from);
+            // e.g. `--from ruff`, no special handling
+            let Some((name, version)) = from.split_once('@') else {
+                return Self::From(target, from);
+            };
+
+            // e.g. `--from ruff@`, warn and treat the whole thing as the command
+            if version.is_empty() {
+                debug!("Ignoring empty version request in `--from`");
+                return Self::From(target, from);
+            }
+
+            // e.g., ignore `git+https://github.com/astral-sh/ruff.git@main`
+            if PackageName::from_str(name).is_err() {
+                debug!("Ignoring non-package name `{name}` in `--from`");
+                return Self::From(target, from);
+            }
+
+            match version {
+                // e.g., `ruff@latest`
+                "latest" => return Self::FromLatest(target, name),
+                // e.g., `ruff@0.6.0`
+                version => {
+                    if let Ok(version) = Version::from_str(version) {
+                        return Self::FromVersion(target, name, version);
+                    }
+                }
+            };
+
+            // e.g. `--from ruff@invalid`, warn and treat the whole thing as the command
+            debug!("Ignoring invalid version request `{version}` in `--from`");
+            return Self::From(target, from);
         }
 
         // e.g. `ruff`, no special handling
@@ -72,12 +106,14 @@ impl<'a> Target<'a> {
             Self::Unspecified(name) => name,
             Self::Version(name, _) => name,
             Self::Latest(name) => name,
-            Self::UserDefined(name, _) => name,
+            Self::FromVersion(name, _, _) => name,
+            Self::FromLatest(name, _) => name,
+            Self::From(name, _) => name,
         }
     }
 
     /// Returns `true` if the target is `latest`.
     fn is_latest(&self) -> bool {
-        matches!(self, Self::Latest(_))
+        matches!(self, Self::Latest(_) | Self::FromLatest(_, _))
     }
 }

crates/uv/src/commands/tool/run.rs

@@ -352,7 +352,7 @@ async fn get_or_create_environment(
             origin: None,
         },
         // Ex) `ruff@0.6.0`
-        Target::Version(name, version) => Requirement {
+        Target::Version(name, version) | Target::FromVersion(_, name, version) => Requirement {
             name: PackageName::from_str(name)?,
             extras: vec![],
             marker: MarkerTree::default(),
@@ -365,7 +365,7 @@ async fn get_or_create_environment(
             origin: None,
         },
         // Ex) `ruff@latest`
-        Target::Latest(name) => Requirement {
+        Target::Latest(name) | Target::FromLatest(_, name) => Requirement {
             name: PackageName::from_str(name)?,
             extras: vec![],
             marker: MarkerTree::default(),
@@ -376,7 +376,7 @@ async fn get_or_create_environment(
             origin: None,
         },
         // Ex) `ruff>=0.6.0`
-        Target::UserDefined(_, from) => resolve_names(
+        Target::From(_, from) => resolve_names(
             vec![RequirementsSpecification::parse_package(from)?],
             &interpreter,
             settings,

crates/uv/tests/tool_install.rs

@@ -2657,6 +2657,94 @@ fn tool_install_at_latest() {
     });
 }
 
+/// Test installing a tool with `uv tool install {package} --from {package}@latest`.
+#[test]
+fn tool_install_from_at_latest() {
+    let context = TestContext::new("3.12")
+        .with_filtered_counts()
+        .with_filtered_exe_suffix();
+    let tool_dir = context.temp_dir.child("tools");
+    let bin_dir = context.temp_dir.child("bin");
+
+    uv_snapshot!(context.filters(), context.tool_install()
+        .arg("pybabel")
+        .arg("--from")
+        .arg("babel@latest")
+        .env("UV_TOOL_DIR", tool_dir.as_os_str())
+        .env("XDG_BIN_HOME", bin_dir.as_os_str())
+        .env("PATH", bin_dir.as_os_str()), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved [N] packages in [TIME]
+    Prepared [N] packages in [TIME]
+    Installed [N] packages in [TIME]
+     + babel==2.14.0
+    Installed 1 executable: pybabel
+    "###);
+
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(fs_err::read_to_string(tool_dir.join("babel").join("uv-receipt.toml")).unwrap(), @r###"
+        [tool]
+        requirements = [{ name = "babel" }]
+        entrypoints = [
+            { name = "pybabel", install-path = "[TEMP_DIR]/bin/pybabel" },
+        ]
+
+        [tool.options]
+        exclude-newer = "2024-03-25T00:00:00Z"
+        "###);
+    });
+}
+
+/// Test installing a tool with `uv tool install {package} --from {package}@{version}`.
+#[test]
+fn tool_install_from_at_version() {
+    let context = TestContext::new("3.12")
+        .with_filtered_counts()
+        .with_filtered_exe_suffix();
+    let tool_dir = context.temp_dir.child("tools");
+    let bin_dir = context.temp_dir.child("bin");
+
+    uv_snapshot!(context.filters(), context.tool_install()
+        .arg("pybabel")
+        .arg("--from")
+        .arg("babel@2.13.0")
+        .env("UV_TOOL_DIR", tool_dir.as_os_str())
+        .env("XDG_BIN_HOME", bin_dir.as_os_str())
+        .env("PATH", bin_dir.as_os_str()), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved [N] packages in [TIME]
+    Prepared [N] packages in [TIME]
+    Installed [N] packages in [TIME]
+     + babel==2.13.0
+    Installed 1 executable: pybabel
+    "###);
+
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(fs_err::read_to_string(tool_dir.join("babel").join("uv-receipt.toml")).unwrap(), @r###"
+        [tool]
+        requirements = [{ name = "babel", specifier = "==2.13.0" }]
+        entrypoints = [
+            { name = "pybabel", install-path = "[TEMP_DIR]/bin/pybabel" },
+        ]
+
+        [tool.options]
+        exclude-newer = "2024-03-25T00:00:00Z"
+        "###);
+    });
+}
+
 /// Test upgrading an already installed tool via `{package}@{latest}`.
 #[test]
 fn tool_install_at_latest_upgrade() {