fix(switch): support - shorthand

CHANGELOG.md

@@ -9,6 +9,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased] - ReleaseDate
 
+- (#1463): `git switch` now accepts a revset that evaluates to a set with a single head, and that head will be checked out
+
 ## [v0.10.0] - 2024-10-10
 
 ### Added

git-branchless-lib/src/git/repo.rs

@@ -938,6 +938,9 @@ impl Repo {
             return Err(Error::UnsupportedRevParseSpec(spec.to_owned()));
         }
 
+        // `libgit2` doesn't understand that `-` is short for `@{-1}`
+        let spec = if spec == "-" { "@{-1}" } else { spec };
+
         match self.inner.revparse_single(spec) {
             Ok(object) => match object.into_commit() {
                 Ok(commit) => Ok(Some(Commit { inner: commit })),

git-branchless/tests/test_navigation.rs

@@ -909,6 +909,32 @@ fn test_navigation_switch_revset() -> eyre::Result<()> {
         "###);
     }
 
+    {
+        // switching back to "last checkout"
+        let (stdout, _stderr) = git.branchless("switch", &["@{-1}"])?;
+        insta::assert_snapshot!(stdout, @r###"
+        branchless: running command: <git-executable> checkout @{-1}
+        O f777ecc (master) create initial.txt
+        |\
+        | o 62fc20d create test1.txt
+        |
+        @ fe65c1f create test2.txt
+        "###);
+    }
+
+    {
+        // switching back to "last checkout"
+        let (stdout, _stderr) = git.branchless("switch", &["-"])?;
+        insta::assert_snapshot!(stdout, @r###"
+        branchless: running command: <git-executable> checkout -
+        @ f777ecc (master) create initial.txt
+        |\
+        | o 62fc20d create test1.txt
+        |
+        o fe65c1f create test2.txt
+        "###);
+    }
+
     Ok(())
 }