Add branch and tag variants to Git reference (#3374)

## Summary

Closes https://github.com/astral-sh/uv/issues/3368.

crates/uv-git/src/git.rs

@@ -25,6 +25,12 @@ const CHECKOUT_READY_LOCK: &str = ".ok";
 /// A reference to commit or commit-ish.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum GitReference {
+    /// A specific branch.
+    Branch(String),
+    /// A specific tag.
+    Tag(String),
+    /// A specific (short) commit.
+    ShortCommit(String),
     /// From a reference that's ambiguously a branch or tag.
     BranchOrTag(String),
     /// From a reference that's ambiguously a short commit, a branch, or a tag.
@@ -46,7 +52,8 @@ enum RefspecStrategy {
 }
 
 impl GitReference {
-    /// Creates a [`GitReference`] from a revision string.
+    /// Creates a [`GitReference`] from an arbitrary revision string, which could represent a
+    /// branch, tag, commit, or named ref.
     pub(crate) fn from_rev(rev: &str) -> Self {
         if rev.starts_with("refs/") {
             Self::NamedRef(rev.to_owned())
@@ -64,9 +71,12 @@ impl GitReference {
     /// Converts the [`GitReference`] to a `str`.
     pub fn as_str(&self) -> Option<&str> {
         match self {
+            Self::Tag(rev) => Some(rev),
+            Self::Branch(rev) => Some(rev),
+            Self::ShortCommit(rev) => Some(rev),
             Self::BranchOrTag(rev) => Some(rev),
-            Self::FullCommit(rev) => Some(rev),
             Self::BranchOrTagOrCommit(rev) => Some(rev),
+            Self::FullCommit(rev) => Some(rev),
             Self::NamedRef(rev) => Some(rev),
             Self::DefaultBranch => None,
         }
@@ -75,10 +85,13 @@ impl GitReference {
     /// Converts the [`GitReference`] to a `str` that can be used as a revision.
     pub(crate) fn as_rev(&self) -> &str {
         match self {
-            Self::BranchOrTag(rev)
+            Self::Tag(rev) => rev,
-            | Self::FullCommit(rev)
+            Self::Branch(rev) => rev,
-            | Self::BranchOrTagOrCommit(rev)
+            Self::ShortCommit(rev) => rev,
-            | Self::NamedRef(rev) => rev,
+            Self::BranchOrTag(rev) => rev,
+            Self::BranchOrTagOrCommit(rev) => rev,
+            Self::FullCommit(rev) => rev,
+            Self::NamedRef(rev) => rev,
             Self::DefaultBranch => "HEAD",
         }
     }
@@ -86,6 +99,9 @@ impl GitReference {
     /// Returns the kind of this reference.
     pub(crate) fn kind_str(&self) -> &str {
         match self {
+            Self::Branch(_) => "branch",
+            Self::Tag(_) => "tag",
+            Self::ShortCommit(_) => "short commit",
             Self::BranchOrTag(_) => "branch or tag",
             Self::FullCommit(_) => "commit",
             Self::BranchOrTagOrCommit(_) => "branch, tag, or commit",
@@ -262,6 +278,26 @@ impl GitReference {
     pub(crate) fn resolve(&self, repo: &git2::Repository) -> Result<git2::Oid> {
         let refkind = self.kind_str();
         let id = match self {
+            Self::Tag(s) => (|| -> Result<git2::Oid> {
+                let refname = format!("refs/remotes/origin/tags/{s}");
+                let id = repo.refname_to_id(&refname)?;
+                let obj = repo.find_object(id, None)?;
+                let obj = obj.peel(ObjectType::Commit)?;
+                Ok(obj.id())
+            })()
+            .with_context(|| format!("failed to find tag `{s}`"))?,
+
+            Self::Branch(s) => {
+                let name = format!("origin/{s}");
+
+                // Resolve the remote name since that's all we're configuring in
+                // `fetch` below.
+                repo.find_branch(&name, git2::BranchType::Remote)
+                    .ok()
+                    .and_then(|b| b.get().target())
+                    .ok_or_else(|| anyhow::format_err!("failed to find {refkind} `{s}`"))?
+            }
+
             // Attempt to resolve the branch, then the tag.
             Self::BranchOrTag(s) => {
                 let name = format!("origin/{s}");
@@ -312,14 +348,14 @@ impl GitReference {
                     .ok_or_else(|| anyhow::format_err!("failed to find {refkind} `{s}`"))?
             }
 
-            // We'll be using the HEAD commit
+            // We'll be using the HEAD commit.
             Self::DefaultBranch => {
                 let head_id = repo.refname_to_id("refs/remotes/origin/HEAD")?;
                 let head = repo.find_object(head_id, None)?;
                 head.peel(ObjectType::Commit)?.id()
             }
 
-            Self::FullCommit(s) | Self::NamedRef(s) => {
+            Self::FullCommit(s) | Self::ShortCommit(s) | Self::NamedRef(s) => {
                 let obj = repo.revparse_single(s)?;
                 match obj.as_tag() {
                     Some(tag) => tag.target_id(),
@@ -949,6 +985,14 @@ pub(crate) fn fetch(
     match reference {
         // For branches and tags we can fetch simply one reference and copy it
         // locally, no need to fetch other branches/tags.
+        GitReference::Branch(branch) => {
+            refspecs.push(format!("+refs/heads/{branch}:refs/remotes/origin/{branch}"));
+        }
+
+        GitReference::Tag(tag) => {
+            refspecs.push(format!("+refs/tags/{tag}:refs/remotes/origin/tags/{tag}"));
+        }
+
         GitReference::BranchOrTag(branch_or_tag) => {
             refspecs.push(format!(
                 "+refs/heads/{branch_or_tag}:refs/remotes/origin/{branch_or_tag}"
@@ -961,7 +1005,8 @@ pub(crate) fn fetch(
 
         // For ambiguous references, we can fetch the exact commit (if known); otherwise,
         // we fetch all branches and tags.
-        GitReference::BranchOrTagOrCommit(branch_or_tag_or_commit) => {
+        GitReference::ShortCommit(branch_or_tag_or_commit)
+        | GitReference::BranchOrTagOrCommit(branch_or_tag_or_commit) => {
             // The `oid_to_fetch` is the exact commit we want to fetch. But it could be the exact
             // commit of a branch or tag. We should only fetch it directly if it's the exact commit
             // of a short commit hash.
@@ -1329,10 +1374,14 @@ fn github_fast_path(
 
     let local_object = reference.resolve(repo).ok();
     let github_branch_name = match reference {
+        GitReference::Branch(branch) => branch,
+        GitReference::Tag(tag) => tag,
         GitReference::BranchOrTag(branch_or_tag) => branch_or_tag,
         GitReference::DefaultBranch => "HEAD",
         GitReference::NamedRef(rev) => rev,
-        GitReference::FullCommit(rev) | GitReference::BranchOrTagOrCommit(rev) => {
+        GitReference::FullCommit(rev)
+        | GitReference::ShortCommit(rev)
+        | GitReference::BranchOrTagOrCommit(rev) => {
             // `revparse_single` (used by `resolve`) is the only way to turn
             // short hash -> long hash, but it also parses other things,
             // like branch and tag names, which might coincidentally be

crates/uv-git/src/lib.rs

@@ -104,7 +104,10 @@ impl From<GitUrl> for Url {
         } else {
             // Otherwise, add the branch or tag name.
             match git.reference {
-                GitReference::BranchOrTag(rev)
+                GitReference::Branch(rev)
+                | GitReference::Tag(rev)
+                | GitReference::ShortCommit(rev)
+                | GitReference::BranchOrTag(rev)
                 | GitReference::NamedRef(rev)
                 | GitReference::FullCommit(rev)
                 | GitReference::BranchOrTagOrCommit(rev) => {

crates/uv-requirements/src/pyproject.rs

@@ -426,18 +426,19 @@ pub(crate) fn lower_requirement(
             if matches!(requirement.version_or_url, Some(VersionOrUrl::Url(_))) {
                 return Err(LoweringError::ConflictingUrls);
             }
-            // TODO(konsti): We know better than this enum
             let reference = match (rev, tag, branch) {
                 (None, None, None) => GitReference::DefaultBranch,
                 (Some(rev), None, None) => {
-                    if rev.len() == 40 {
+                    if rev.starts_with("refs/") {
-                        GitReference::FullCommit(rev)
+                        GitReference::NamedRef(rev.clone())
+                    } else if rev.len() == 40 {
+                        GitReference::FullCommit(rev.clone())
                     } else {
-                        GitReference::BranchOrTagOrCommit(rev)
+                        GitReference::ShortCommit(rev.clone())
                     }
                 }
-                (None, Some(tag), None) => GitReference::BranchOrTag(tag),
+                (None, Some(tag), None) => GitReference::Tag(tag),
-                (None, None, Some(branch)) => GitReference::BranchOrTag(branch),
+                (None, None, Some(branch)) => GitReference::Branch(branch),
                 _ => return Err(LoweringError::MoreThanOneGitRef),
             };
 

crates/uv/tests/pip_compile.rs

@@ -8389,3 +8389,266 @@ fn resolve_configuration() -> Result<()> {
 
     Ok(())
 }
+
+/// Resolve a specific source distribution via a Git HTTPS dependency.
+#[test]
+#[cfg(feature = "git")]
+fn git_source_default_branch() -> 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 = "0.0.0"
+        dependencies = [
+          "uv-public-pypackage",
+        ]
+
+        [tool.uv.sources]
+        uv-public-pypackage = { git = "https://github.com/astral-test/uv-public-pypackage" }
+    "#})?;
+
+    // In addition to the standard filters, remove the `main` commit, which will change frequently.
+    let filters: Vec<_> = [(r"@(\d|\w){40}", "@[COMMIT]")]
+        .into_iter()
+        .chain(context.filters())
+        .collect();
+
+    uv_snapshot!(filters, context.compile()
+            .arg("--preview")
+            .arg("pyproject.toml"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] --exclude-newer 2024-03-25T00:00:00Z --preview pyproject.toml
+    uv-public-pypackage @ git+https://github.com/astral-test/uv-public-pypackage@[COMMIT]
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    "###);
+
+    Ok(())
+}
+
+/// Resolve a specific branch via a Git HTTPS dependency.
+#[test]
+#[cfg(feature = "git")]
+fn git_source_branch() -> 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 = "0.0.0"
+        dependencies = [
+          "uv-public-pypackage",
+        ]
+
+        [tool.uv.sources]
+        uv-public-pypackage = { git = "https://github.com/astral-test/uv-public-pypackage", branch = "test-branch" }
+    "#})?;
+
+    uv_snapshot!(context.compile()
+            .arg("--preview")
+            .arg("pyproject.toml"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] --exclude-newer 2024-03-25T00:00:00Z --preview pyproject.toml
+    uv-public-pypackage @ git+https://github.com/astral-test/uv-public-pypackage@0dacfd662c64cb4ceb16e6cf65a157a8b715b979
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    "###);
+
+    Ok(())
+}
+
+/// Resolve a specific tag via a Git HTTPS dependency.
+#[test]
+#[cfg(feature = "git")]
+fn git_source_tag() -> 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 = "0.0.0"
+        dependencies = [
+          "uv-public-pypackage",
+        ]
+
+        [tool.uv.sources]
+        uv-public-pypackage = { git = "https://github.com/astral-test/uv-public-pypackage", tag = "test-tag" }
+    "#})?;
+
+    uv_snapshot!(context.compile()
+            .arg("--preview")
+            .arg("pyproject.toml"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] --exclude-newer 2024-03-25T00:00:00Z --preview pyproject.toml
+    uv-public-pypackage @ git+https://github.com/astral-test/uv-public-pypackage@0dacfd662c64cb4ceb16e6cf65a157a8b715b979
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    "###);
+
+    Ok(())
+}
+
+/// Resolve a specific commit via a Git HTTPS dependency.
+#[test]
+#[cfg(feature = "git")]
+fn git_source_long_commit() -> 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 = "0.0.0"
+        dependencies = [
+          "uv-public-pypackage",
+        ]
+
+        [tool.uv.sources]
+        uv-public-pypackage = { git = "https://github.com/astral-test/uv-public-pypackage", rev = "0dacfd662c64cb4ceb16e6cf65a157a8b715b979" }
+    "#})?;
+
+    uv_snapshot!(context.compile()
+            .arg("--preview")
+            .arg("pyproject.toml"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] --exclude-newer 2024-03-25T00:00:00Z --preview pyproject.toml
+    uv-public-pypackage @ git+https://github.com/astral-test/uv-public-pypackage@0dacfd662c64cb4ceb16e6cf65a157a8b715b979
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    "###);
+
+    Ok(())
+}
+
+/// Resolve a specific commit via a Git HTTPS dependency.
+#[test]
+#[cfg(feature = "git")]
+fn git_source_short_commit() -> 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 = "0.0.0"
+        dependencies = [
+          "uv-public-pypackage",
+        ]
+
+        [tool.uv.sources]
+        uv-public-pypackage = { git = "https://github.com/astral-test/uv-public-pypackage", rev = "0dacfd6" }
+    "#})?;
+
+    uv_snapshot!(context.compile()
+            .arg("--preview")
+            .arg("pyproject.toml"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] --exclude-newer 2024-03-25T00:00:00Z --preview pyproject.toml
+    uv-public-pypackage @ git+https://github.com/astral-test/uv-public-pypackage@0dacfd662c64cb4ceb16e6cf65a157a8b715b979
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    "###);
+
+    Ok(())
+}
+
+/// Resolve a specific ref via a Git HTTPS dependency.
+#[test]
+#[cfg(feature = "git")]
+fn git_source_refs() -> 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 = "0.0.0"
+        dependencies = [
+          "uv-public-pypackage",
+        ]
+
+        [tool.uv.sources]
+        uv-public-pypackage = { git = "https://github.com/astral-test/uv-public-pypackage", rev = "refs/pull/4/head" }
+    "#})?;
+
+    uv_snapshot!(context.compile()
+            .arg("--preview")
+            .arg("pyproject.toml"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] --exclude-newer 2024-03-25T00:00:00Z --preview pyproject.toml
+    uv-public-pypackage @ git+https://github.com/astral-test/uv-public-pypackage@9d01a806f17ddacb9c7b66b1b68574adf790b63f
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    "###);
+
+    Ok(())
+}
+
+/// Request a non-existent tag via a Git HTTPS dependency.
+#[test]
+#[cfg(feature = "git")]
+#[cfg_attr(windows, ignore = "Git error messages differ on Windows")]
+fn git_source_missing_tag() -> 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 = "0.0.0"
+        dependencies = [
+          "uv-public-pypackage",
+        ]
+
+        [tool.uv.sources]
+        uv-public-pypackage = { git = "https://github.com/astral-test/uv-public-pypackage", tag = "missing" }
+    "#})?;
+
+    uv_snapshot!(context.filters(), context.compile()
+            .arg("--preview")
+            .arg("pyproject.toml"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: Failed to download and build: `uv-public-pypackage @ git+https://github.com/astral-test/uv-public-pypackage@missing`
+      Caused by: Git operation failed
+      Caused by: failed to clone into: [CACHE_DIR]/git-v0/db/8dab139913c4b566
+      Caused by: failed to fetch branch or tag `missing`
+      Caused by: process didn't exit successfully: `git fetch --force --update-head-ok 'https://github.com/astral-test/uv-public-pypackage' '+refs/tags/missing:refs/remotes/origin/tags/missing'` (exit status: 128)
+    --- stderr
+    fatal: couldn't find remote ref refs/tags/missing
+
+    "###);
+
+    Ok(())
+}