test_git.py

# SPDX-FileCopyrightText: 2022 Felix Gruber <felgru@posteo.net>
#
# SPDX-License-Identifier: GPL-3.0-or-later

from pathlib import Path

import pytest

from git import (
    Conflict,
    Git,
    GitError,
    GitEmptyCommitError,
    GitMergeConflictError,
)


def test_create_git_dir(tmp_path: Path) -> None:
    Git.create(tmp_path)
    assert (tmp_path / '.git').exists()


def test_create_commit(tmp_path: Path) -> None:
    git = Git.create(tmp_path)
    my_file = tmp_path / 'a'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add a')


def test_empty_commit_raises_error(tmp_path: Path) -> None:
    git = Git.create(tmp_path)
    my_file = tmp_path / 'a'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add a')
    with pytest.raises(GitEmptyCommitError):
        git.commit('Empty commit.')


def test_empty_commit_in_dirty_working_dir_raises_error(tmp_path: Path) -> None:
    git = Git.create(tmp_path)
    my_file = tmp_path / 'a'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add a')
    (tmp_path / 'b').touch()
    with pytest.raises(GitEmptyCommitError):
        git.commit('Empty commit.')


def test_checkout_current_branch(tmp_path: Path) -> None:
    # The master branch only gets created once we create a first commit.
    git = Git.create(tmp_path)
    my_file = tmp_path / 'a'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add a')

    current_branch = git.current_branch()
    git.change_branch(current_branch)
    assert git.current_branch() == current_branch


def test_create_branch(tmp_path: Path) -> None:
    # Create_branch does not work in an empty repository.
    # Hence, I create a commit on the master branch.
    git = Git.create(tmp_path)
    my_file = tmp_path / 'a'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add a')

    # Now create the new branch
    original_branch = git.current_branch()
    new_branch = 'my-new-branch'
    git.create_branch(new_branch)
    assert git.current_branch() == original_branch


def test_checkout_new_branch(tmp_path: Path) -> None:
    # Create_branch does not work in an empty repository.
    # Hence, I create a commit on the master branch.
    git = Git.create(tmp_path)
    my_file = tmp_path / 'a'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add a')

    new_branch = 'my-new-branch'
    git.create_branch(new_branch, switch=True)
    assert git.current_branch() == new_branch


def test_checkout_nonexistent_branch(tmp_path: Path) -> None:
    git = Git.create(tmp_path)
    with pytest.raises(GitError, match='switch to non-existent branch'):
        git.change_branch('nonexistent')


def test_merge(tmp_path: Path) -> None:
    git = Git.create(tmp_path)
    my_file = tmp_path / 'a'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add a')

    main_branch = git.current_branch()
    git.create_branch('b', switch=True)
    my_file = tmp_path / 'b'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add b')

    git.change_branch(main_branch)
    my_file = tmp_path / 'c'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add c')

    git.merge('b')

    assert (tmp_path / 'a').exists()
    assert (tmp_path / 'b').exists()
    assert (tmp_path / 'c').exists()


def test_merge_conflict(tmp_path: Path) -> None:
    git = Git.create(tmp_path)
    my_file = tmp_path / 'a'
    my_file.touch()
    git.add_file(my_file)
    git.commit('Add a')

    main_branch = git.current_branch()
    git.create_branch('bad', switch=True)
    my_file = tmp_path / 'a'
    with my_file.open('w') as f:
        f.write('1')
    git.add_file(my_file)
    my_file = tmp_path / 'b'
    with my_file.open('w') as f:
        f.write('1')
    git.add_file(my_file)
    git.commit('Add b')

    git.change_branch(main_branch)
    my_file = tmp_path / 'a'
    with my_file.open('w') as f:
        f.write('2')
    git.add_file(my_file)
    my_file = tmp_path / 'b'
    with my_file.open('w') as f:
        f.write('2')
    git.add_file(my_file)
    git.commit('Add b')

    with pytest.raises(GitMergeConflictError) as exc_info:
        git.merge('bad')
    conflicts = exc_info.value.conflicts
    assert set(conflicts) == {
        Conflict(name='a', type='content'),
        Conflict(name='b', type='add/add'),
    }