Initialise a empty default bundle if BUNDLE_ROOT and DATABRICKS_BUNDLE_INCLUDES env vars are present (#604)

## Changes
<!-- Summary of your changes that are easy to understand -->

## Tests
<!-- How is this tested? -->

bundle/bundle.go

@@ -43,10 +43,27 @@ type Bundle struct {
 	AutoApprove bool
 }
 
+const ExtraIncludePathsKey string = "DATABRICKS_BUNDLE_INCLUDES"
+
 func Load(path string) (*Bundle, error) {
 	bundle := &Bundle{}
+	stat, err := os.Stat(path)
+	if err != nil {
+		return nil, err
+	}
 	configFile, err := config.FileNames.FindInPath(path)
 	if err != nil {
+		_, hasIncludePathEnv := os.LookupEnv(ExtraIncludePathsKey)
+		_, hasBundleRootEnv := os.LookupEnv(envBundleRoot)
+		if hasIncludePathEnv && hasBundleRootEnv && stat.IsDir() {
+			bundle.Config = config.Root{
+				Path: path,
+				Bundle: config.Bundle{
+					Name: filepath.Base(path),
+				},
+			}
+			return bundle, nil
+		}
 		return nil, err
 	}
 	err = bundle.Config.Load(configFile)

bundle/config/mutator/process_root_includes.go

@@ -12,11 +12,9 @@ import (
 	"golang.org/x/exp/slices"
 )
 
-const ExtraIncludePathsKey string = "DATABRICKS_BUNDLE_INCLUDES"
-
 // Get extra include paths from environment variable
 func GetExtraIncludePaths() []string {
-	value, exists := os.LookupEnv(ExtraIncludePathsKey)
+	value, exists := os.LookupEnv(bundle.ExtraIncludePathsKey)
 	if !exists {
 		return nil
 	}

bundle/config/mutator/process_root_includes_test.go

@@ -129,9 +129,9 @@ func TestProcessRootIncludesExtrasFromEnvVar(t *testing.T) {
 	rootPath := t.TempDir()
 	testYamlName := "extra_include_path.yml"
 	touch(t, rootPath, testYamlName)
-	os.Setenv(mutator.ExtraIncludePathsKey, path.Join(rootPath, testYamlName))
+	os.Setenv(bundle.ExtraIncludePathsKey, path.Join(rootPath, testYamlName))
 	t.Cleanup(func() {
-		os.Unsetenv(mutator.ExtraIncludePathsKey)
+		os.Unsetenv(bundle.ExtraIncludePathsKey)
 	})
 
 	bundle := &bundle.Bundle{
@@ -149,7 +149,7 @@ func TestProcessRootIncludesDedupExtrasFromEnvVar(t *testing.T) {
 	rootPath := t.TempDir()
 	testYamlName := "extra_include_path.yml"
 	touch(t, rootPath, testYamlName)
-	t.Setenv(mutator.ExtraIncludePathsKey, fmt.Sprintf("%s%s%s", path.Join(rootPath, testYamlName), string(os.PathListSeparator), path.Join(rootPath, testYamlName)))
+	t.Setenv(bundle.ExtraIncludePathsKey, fmt.Sprintf("%s%s%s", path.Join(rootPath, testYamlName), string(os.PathListSeparator), path.Join(rootPath, testYamlName)))
 
 	bundle := &bundle.Bundle{
 		Config: config.Root{

bundle/root_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	"github.com/databricks/cli/bundle/config"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -102,3 +103,45 @@ func TestRootLookupError(t *testing.T) {
 	_, err := mustGetRoot()
 	require.ErrorContains(t, err, "unable to locate bundle root")
 }
+
+func TestLoadYamlWhenIncludesEnvPresent(t *testing.T) {
+	chdir(t, filepath.Join(".", "tests", "basic"))
+	t.Setenv(ExtraIncludePathsKey, "test")
+
+	bundle, err := MustLoad()
+	assert.NoError(t, err)
+	assert.Equal(t, "basic", bundle.Config.Bundle.Name)
+
+	cwd, err := os.Getwd()
+	assert.NoError(t, err)
+	assert.Equal(t, cwd, bundle.Config.Path)
+}
+
+func TestLoadDefautlBundleWhenNoYamlAndRootAndIncludesEnvPresent(t *testing.T) {
+	dir := t.TempDir()
+	chdir(t, dir)
+	t.Setenv(envBundleRoot, dir)
+	t.Setenv(ExtraIncludePathsKey, "test")
+
+	bundle, err := MustLoad()
+	assert.NoError(t, err)
+	assert.Equal(t, dir, bundle.Config.Path)
+}
+
+func TestErrorIfNoYamlNoRootEnvAndIncludesEnvPresent(t *testing.T) {
+	dir := t.TempDir()
+	chdir(t, dir)
+	t.Setenv(ExtraIncludePathsKey, "test")
+
+	_, err := MustLoad()
+	assert.Error(t, err)
+}
+
+func TestErrorIfNoYamlNoIncludesEnvAndRootEnvPresent(t *testing.T) {
+	dir := t.TempDir()
+	chdir(t, dir)
+	t.Setenv(envBundleRoot, dir)
+
+	_, err := MustLoad()
+	assert.Error(t, err)
+}