Test detached head with force flag

So long as the detached head isn't pointed to by another branch,
the --force flag will cause staged changes to be committed.

Author: blairconrad

src/lib.rs

@@ -645,6 +645,27 @@ mod tests {
         assert!(is_something_in_index);
     }
 
+    #[test]
+    fn detached_head_with_force_flag() {
+        let ctx = repo_utils::prepare_and_stage();
+        repo_utils::detach_head(&ctx);
+        repo_utils::delete_branch(&ctx.repo, "master");
+
+        // run 'git-absorb'
+        let drain = slog::Discard;
+        let logger = slog::Logger::root(drain, o!());
+        let config = Config {
+            force: true,
+            ..DEFAULT_CONFIG
+        };
+        run_with_repo(&logger, &config, &ctx.repo).unwrap();
+        let mut revwalk = ctx.repo.revwalk().unwrap();
+        revwalk.push_head().unwrap();
+
+        assert_eq!(revwalk.count(), 3);
+        assert!(nothing_left_in_index(&ctx.repo).unwrap());
+    }
+
     #[test]
     fn attached_head_pointing_at_commit_on_a_second_branch() {
         let ctx = repo_utils::prepare_and_stage();

src/tests/repo_utils.rs

@@ -96,3 +96,11 @@ pub fn add_branch(repo: &git2::Repository, branch_name: &str) {
     let head_commit = head.peel_to_commit().unwrap();
     repo.branch(branch_name, &head_commit, false).unwrap();
 }
+
+/// Delete the branch with the given name.
+pub fn delete_branch(repo: &git2::Repository, branch_name: &str) {
+    let mut branch = repo
+        .find_branch(branch_name, git2::BranchType::Local)
+        .unwrap();
+    branch.delete().unwrap();
+}