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-navigation/src/lib.rs

@@ -521,6 +521,11 @@ pub fn switch(
         (true, None) => Target::Interactive(String::new()),
         (false, Some(target)) => match repo.revparse_single_commit(target.to_string().as_ref()) {
             Ok(Some(_)) => Target::Revision(target.to_string()),
+            // special case: - is shorthand for @{-1} but isn't supported as
+            // such by revparse_single_commit() or as a revset
+            Ok(None) | Err(_) if target.to_string().as_str() == "-" => {
+                Target::Revision(target.to_string())
+            }
             Ok(None) | Err(_) => Target::Revset(target.clone()),
         },
         (false, None) => Target::None,

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(())
 }