Add --show-current flag to the branch subcommand

Author: SandrineP

src/subcommand/branch_subcommand.cpp

@@ -14,6 +14,7 @@ branch_subcommand::branch_subcommand(const libgit2_object&, CLI::App& app)
     sub->add_flag("-r,--remotes", m_remote_flag, "List or delete (if used with -d) the remote-tracking branches");
     sub->add_flag("-l,--list", m_list_flag, "List branches");
     sub->add_flag("-f,--force", m_force_flag, "Skips confirmation");
+    sub->add_flag("--show-current", m_show_current_flag, "Print the name of the current branch. In detached HEAD state, nothing is printed.");
 
     sub->callback([this]() { this->run(); });
 }
@@ -23,7 +24,12 @@ void branch_subcommand::run()
     auto directory = get_current_git_path();
     auto repo = repository_wrapper::open(directory);
 
-    if (m_list_flag || m_branch_name.empty())
+    if (m_show_current_flag)
+    {
+        // TODO: if another flag, return usage/Generic options/Specific git-branch actions
+        run_show_current(repo);
+    }
+    else if (m_list_flag || m_branch_name.empty())
     {
         run_list(repo);
     }
@@ -64,9 +70,20 @@ void branch_subcommand::run_deletion(repository_wrapper& repo)
     delete_branch(std::move(branch));
 }
 
-
 void branch_subcommand::run_creation(repository_wrapper& repo)
 {
     // TODO: handle specification of starting commit
     repo.create_branch(m_branch_name, m_force_flag);
 }
+
+void branch_subcommand::run_show_current(const repository_wrapper& repo)
+{
+    auto name = repo.head_short_name();
+
+    if (name == "HEAD")
+    {
+        return;
+    }
+
+    std::cout << name << std::endl;
+}

src/subcommand/branch_subcommand.hpp

@@ -19,11 +19,13 @@ class branch_subcommand
     void run_list(const repository_wrapper& repo);
     void run_deletion(repository_wrapper& repo);
     void run_creation(repository_wrapper& repo);
+    void run_show_current(const repository_wrapper& repo);
 
     std::string m_branch_name = {};
     bool m_deletion_flag = false;
     bool m_all_flag = false;
     bool m_remote_flag = false;
     bool m_list_flag = false;
     bool m_force_flag = false;
+    bool m_show_current_flag = false;
 };

test/test_branch.py

@@ -9,7 +9,7 @@ def test_branch_list(repo_init_with_commit, git2cpp_path, tmp_path):
     cmd = [git2cpp_path, "branch"]
     p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
     assert p.returncode == 0
-    assert "* ma" in p.stdout
+    assert "* main" in p.stdout
 
 
 def test_branch_create_delete(repo_init_with_commit, git2cpp_path, tmp_path):
@@ -22,15 +22,15 @@ def test_branch_create_delete(repo_init_with_commit, git2cpp_path, tmp_path):
     list_cmd = [git2cpp_path, "branch"]
     p_list = subprocess.run(list_cmd, capture_output=True, cwd=tmp_path, text=True)
     assert p_list.returncode == 0
-    assert "  foregone\n* ma" in p_list.stdout
+    assert "  foregone\n* main" in p_list.stdout
 
     del_cmd = [git2cpp_path, "branch", "-d", "foregone"]
     p_del = subprocess.run(del_cmd, capture_output=True, cwd=tmp_path, text=True)
     assert p_del.returncode == 0
 
     p_list2 = subprocess.run(list_cmd, capture_output=True, cwd=tmp_path, text=True)
     assert p_list2.returncode == 0
-    assert "* ma" in p_list2.stdout
+    assert "* main" in p_list2.stdout
 
 
 def test_branch_nogit(git2cpp_path, tmp_path):
@@ -51,3 +51,174 @@ def test_branch_new_repo(git2cpp_path, tmp_path, run_in_tmp_path):
     p_branch = subprocess.run(branch_cmd, cwd=tmp_path)
 
     assert p_branch.returncode == 0
+
+
+def test_branch_list_flag(repo_init_with_commit, git2cpp_path, tmp_path):
+    """Explicit -l/--list flag behaves the same as bare 'branch'."""
+    assert (tmp_path / "initial.txt").exists()
+
+    subprocess.run([git2cpp_path, "branch", "feature-a"], cwd=tmp_path, check=True)
+
+    for flag in ["-l", "--list"]:
+        cmd = [git2cpp_path, "branch", flag]
+        p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+        assert p.returncode == 0
+        assert "  feature-a" in p.stdout
+        assert "* main" in p.stdout
+
+
+def test_branch_list_all(xtl_clone, git2cpp_path, tmp_path):
+    """The -a/--all flag lists both local and remote-tracking branches."""
+    xtl_path = tmp_path / "xtl"
+
+    cmd = [git2cpp_path, "branch", "-a"]
+    p = subprocess.run(cmd, capture_output=True, cwd=xtl_path, text=True)
+    assert p.returncode == 0
+    assert "* master" in p.stdout
+    assert "origin/" in p.stdout
+
+
+def test_branch_list_remotes(xtl_clone, git2cpp_path, tmp_path):
+    """The -r/--remotes flag lists only remote-tracking branches."""
+    xtl_path = tmp_path / "xtl"
+
+    cmd = [git2cpp_path, "branch", "-r"]
+    p = subprocess.run(cmd, capture_output=True, cwd=xtl_path, text=True)
+    assert p.returncode == 0
+    assert "origin/" in p.stdout
+    # Local branch should NOT appear with * prefix
+    assert "* master" not in p.stdout
+
+
+def test_branch_create_already_exists(repo_init_with_commit, git2cpp_path, tmp_path):
+    """Creating a branch that already exists should fail without --force."""
+    assert (tmp_path / "initial.txt").exists()
+
+    subprocess.run([git2cpp_path, "branch", "duplicate"], cwd=tmp_path, check=True)
+
+    cmd = [git2cpp_path, "branch", "duplicate"]
+    p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+    assert p.returncode != 0
+
+
+def test_branch_create_force_overwrite(
+    repo_init_with_commit, commit_env_config, git2cpp_path, tmp_path
+):
+    """--force allows overwriting an existing branch."""
+    assert (tmp_path / "initial.txt").exists()
+
+    subprocess.run([git2cpp_path, "branch", "my-branch"], cwd=tmp_path, check=True)
+
+    # Add a second commit so HEAD moves forward
+    (tmp_path / "second.txt").write_text("second")
+    subprocess.run([git2cpp_path, "add", "second.txt"], cwd=tmp_path, check=True)
+    subprocess.run(
+        [git2cpp_path, "commit", "-m", "Second commit"], cwd=tmp_path, check=True
+    )
+
+    # Without --force this would fail; with -f it should reset the branch to current HEAD
+    cmd = [git2cpp_path, "branch", "-f", "my-branch"]
+    p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+    assert p.returncode == 0
+
+
+def test_branch_delete_nonexistent(repo_init_with_commit, git2cpp_path, tmp_path):
+    """Deleting a branch that doesn't exist should fail."""
+    assert (tmp_path / "initial.txt").exists()
+
+    cmd = [git2cpp_path, "branch", "-d", "no-such-branch"]
+    p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+    assert p.returncode != 0
+
+
+def test_branch_create_multiple(repo_init_with_commit, git2cpp_path, tmp_path):
+    """Creating multiple branches and verifying they all appear in the listing."""
+    assert (tmp_path / "initial.txt").exists()
+
+    branches = ["alpha", "beta", "gamma"]
+    for name in branches:
+        p = subprocess.run(
+            [git2cpp_path, "branch", name], capture_output=True, cwd=tmp_path, text=True
+        )
+        assert p.returncode == 0
+
+    cmd = [git2cpp_path, "branch"]
+    p_list = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+    assert p_list.returncode == 0
+    for name in branches:
+        assert f"  {name}" in p_list.stdout
+    # Current branch is still starred
+    assert "* main" in p_list.stdout
+
+
+def test_branch_show_current(repo_init_with_commit, git2cpp_path, tmp_path):
+    """--show-current prints the current branch name."""
+    assert (tmp_path / "initial.txt").exists()
+
+    cmd = [git2cpp_path, "branch", "--show-current"]
+    p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+    assert p.returncode == 0
+    print(p.stdout)
+    # Default branch after init is "main" or "master" depending on git config
+    # TODO: update when -b flag is added to the init subcommand
+    assert p.stdout.strip() in ("main", "master")
+
+
+def test_branch_show_current_after_create_and_switch(
+    repo_init_with_commit, git2cpp_path, tmp_path
+):
+    """--show-current reflects the branch we switched to."""
+    assert (tmp_path / "initial.txt").exists()
+
+    subprocess.run(
+        [git2cpp_path, "checkout", "-b", "new-feature"], cwd=tmp_path, check=True
+    )
+
+    cmd = [git2cpp_path, "branch", "--show-current"]
+    p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+    assert p.returncode == 0
+    assert p.stdout == "new-feature\n"
+
+
+def test_branch_show_current_detached_head(
+    repo_init_with_commit, git2cpp_path, tmp_path
+):
+    """--show-current prints nothing when HEAD is detached."""
+    assert (tmp_path / "initial.txt").exists()
+
+    result = subprocess.run(
+        [git2cpp_path, "rev-parse", "HEAD"],
+        capture_output=True,
+        cwd=tmp_path,
+        text=True,
+        check=True,
+    )
+    head_sha = result.stdout.strip()
+    subprocess.run([git2cpp_path, "checkout", head_sha], cwd=tmp_path, check=True)
+
+    cmd = [git2cpp_path, "branch", "--show-current"]
+    p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+    assert p.returncode == 0
+    assert p.stdout == ""
+
+
+def test_branch_show_current_new_repo(git2cpp_path, tmp_path, run_in_tmp_path):
+    """--show-current prints the branch name even on a fresh repo with no commits (unborn HEAD)."""
+    assert list(tmp_path.iterdir()) == []
+
+    subprocess.run([git2cpp_path, "init"], cwd=tmp_path, check=True)
+
+    cmd = [git2cpp_path, "branch", "--show-current"]
+    p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+    assert p.returncode == 0
+    # Default branch after init is "main" or "master" depending on git config
+    # TODO: update when -b flag is added to the init subcommand
+    assert p.stdout.strip() in ("main", "master")
+
+
+def test_branch_show_current_nogit(git2cpp_path, tmp_path):
+    """--show-current fails gracefully outside a git repository."""
+    cmd = [git2cpp_path, "branch", "--show-current"]
+    p = subprocess.run(cmd, capture_output=True, cwd=tmp_path, text=True)
+    assert p.returncode != 0
+    assert "error: could not find repository at" in p.stderr