git_atomic_push_test.go

// SPDX-License-Identifier: Apache-2.0

package git

import (
	"context"
	"path/filepath"
	"testing"

	"github.com/go-git/go-git/v6/plumbing"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// TestAtomicPush_PushOnEmpty tries to push a new commit on an totally empty repo.
func TestAtomicPush_PushOnEmpty(t *testing.T) {
	ctx := context.Background()
	tempDir := t.TempDir()
	serverPath := filepath.Join(tempDir, "server")
	remoteURL := "file://" + serverPath

	// Create bare remote repository with HEAD set to main
	localPath := filepath.Join(tempDir, "local")
	remoteRepo := createBareRepo(t, serverPath)

	// Clone that repo and do a first commit on main
	localRepo, worktree := initLocalRepo(t, localPath, remoteURL, "main")
	createdHash := commitFileChange(t, worktree, localPath, "README.md", "This is cool")

	// New branch in empty repo, so rootHash is plumbing.ZeroHash (let's also include the assumption that we merge to main, so that we can detect if it 'updated')
	branch := plumbing.NewBranchReferenceName("main")
	err := PushAtomic(ctx, localRepo, plumbing.ZeroHash, branch, nil)
	require.NoError(t, err)

	// Verify branch exists on server
	ref, err := remoteRepo.Reference(branch, true)
	require.NoError(t, err)
	assert.NotNil(t, ref)
	require.Equal(t, createdHash, ref.Hash())
}

func TestAtomicPush_PushToMain(t *testing.T) {
	ctx := context.Background()
	tempDir := t.TempDir()
	serverPath := filepath.Join(tempDir, "server")
	remoteURL := "file://" + serverPath

	// Create a remote with one commit
	localPath := filepath.Join(tempDir, "local")
	remoteRepo := createBareRepo(t, serverPath)
	firstCommit := simulateClientCommitOnDisk(t, remoteURL, "main", "README.md", "This is an initialized remote repo")

	// Check it out and create a commit based on that
	localRepo, worktree := initLocalRepo(t, localPath, remoteURL, "main")
	createdCommit := commitFileChange(t, worktree, localPath, "README.md", "This is cool")

	branch := plumbing.NewBranchReferenceName("main")
	err := PushAtomic(ctx, localRepo, firstCommit, branch, nil)
	require.NoError(t, err)

	// Verify branch exists on server
	ref, err := remoteRepo.Reference(branch, true)
	require.NoError(t, err)
	assert.NotNil(t, ref)
	require.Equal(t, createdCommit, ref.Hash())
}

func TestAtomicPush_PushToOther(t *testing.T) {
	ctx := context.Background()
	tempDir := t.TempDir()
	serverPath := filepath.Join(tempDir, "server")
	remoteURL := "file://" + serverPath

	// Create a remote with two commits
	localPath := filepath.Join(tempDir, "local")
	remoteRepo := createBareRepo(t, serverPath)
	firstCommit := simulateClientCommitOnDisk(t, remoteURL, "main", "README.md", "This is an initialized remote repo")

	// Check it out and create a commit based on that
	localRepo, worktree := initLocalRepo(t, localPath, remoteURL, "feature")
	createdCommit := commitFileChange(t, worktree, localPath, "README.md", "This is cool")

	// Now we expect this to error out
	rootBranch := plumbing.NewBranchReferenceName("main")
	featureBranch := plumbing.NewBranchReferenceName("feature")
	err := PushAtomic(ctx, localRepo, firstCommit, rootBranch, nil)
	require.NoError(t, err)
	ref, err := remoteRepo.Reference(featureBranch, true)
	require.NoError(t, err)
	assert.NotNil(t, ref)
	require.Equal(t, createdCommit, ref.Hash())
}

// TestAtomicPush_DetectsMissingBranch tests that push detects when remote branch doesn't exist anymore.
func TestAtomicPush_DetectsMissingBranch(t *testing.T) {
	ctx := context.Background()
	tempDir := t.TempDir()
	serverPath := filepath.Join(tempDir, "server")
	remoteURL := "file://" + serverPath

	// Create a remote with two commits
	localPath := filepath.Join(tempDir, "local")
	remoteRepo := createBareRepo(t, serverPath)
	simulateClientCommitOnDisk(t, remoteURL, "main", "README.md", "This is an initialized remote repo")
	featureCommit := simulateClientCommitOnDisk(t, remoteURL, "feature", "README.md", "Some change")

	// Check it out and create a commit based on that
	localRepo, worktree := initLocalRepo(t, localPath, remoteURL, "feature")
	createdCommit := commitFileChange(t, worktree, localPath, "README.md", "This is cool")
	require.Equal(t, 3, countDepth(t, localRepo, createdCommit))

	// Remove the branch on the remote (simulating that a merge has been done)
	featureBranch := plumbing.NewBranchReferenceName("feature")
	err := remoteRepo.Storer.RemoveReference(featureBranch)
	require.NoError(t, err)

	// Now we epxect this to error out
	err = PushAtomic(ctx, localRepo, featureCommit, featureBranch, nil)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "remote went missing")
}

// TestAtomicPush_DetectsUpdatedRemote should check that a change is deteceted.
func TestAtomicPush_DetectsUpdatedRemote(t *testing.T) {
	ctx := context.Background()
	tempDir := t.TempDir()
	serverPath := filepath.Join(tempDir, "server")
	remoteURL := "file://" + serverPath

	// Create a remote with two commits
	localPath := filepath.Join(tempDir, "local")
	createBareRepo(t, serverPath)
	firstCommit := simulateClientCommitOnDisk(t, remoteURL, "main", "README.md", "This is an initialized remote repo")

	// Check it out and create a commit based on that
	localRepo, worktree := initLocalRepo(t, localPath, remoteURL, "main")
	commitFileChange(t, worktree, localPath, "README.md", "This is cool")

	simulateClientCommitOnDisk(t, remoteURL, "main", "README.md", "Another change on remote!")

	// Now we expect this to error out
	err := PushAtomic(ctx, localRepo, firstCommit, "refs/heads/main", nil)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "remote received unknown updates")
}