Function to find the Git repository containing a bundle (#289)

## Changes

Useful functions from #277.

## Tests

Tests pass.

bundle/bundle.go

@@ -7,11 +7,14 @@
 package bundle
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"sync"
 
 	"github.com/databricks/bricks/bundle/config"
+	"github.com/databricks/bricks/folders"
+	"github.com/databricks/bricks/libs/git"
 	"github.com/databricks/bricks/libs/locker"
 	"github.com/databricks/databricks-sdk-go"
 	"github.com/hashicorp/terraform-exec/tfexec"
@@ -115,3 +118,12 @@ func (b *Bundle) CacheDir(paths ...string) (string, error) {
 
 	return dir, nil
 }
+
+func (b *Bundle) GitRepository() (*git.Repository, error) {
+	rootPath, err := folders.FindDirWithLeaf(b.Config.Path, ".git")
+	if err != nil {
+		return nil, fmt.Errorf("unable to locate repository root: %w", err)
+	}
+
+	return git.NewRepository(rootPath)
+}

libs/git/repository.go

@@ -32,6 +32,11 @@ type Repository struct {
 	ignore map[string][]ignoreRules
 }
 
+// Root returns the repository root.
+func (r *Repository) Root() string {
+	return r.rootPath
+}
+
 // loadConfig loads and combines user specific and repository specific configuration files.
 func (r *Repository) loadConfig() (*config, error) {
 	config, err := globalGitConfig()

libs/git/repository_test.go

@@ -26,6 +26,9 @@ func TestRepository(t *testing.T) {
 	tr := testRepository{t, repo}
 	require.NoError(t, err)
 
+	// Check that the root path is real.
+	assert.True(t, filepath.IsAbs(repo.Root()))
+
 	// Check that top level ignores work.
 	assert.True(t, tr.Ignore(".DS_Store"))
 	assert.True(t, tr.Ignore("foo.pyc"))