909 path folders (#910)

## Description

Adds function call to the path package that returns the folder elements present in a path after the path prefix. This is safer than using `strings.Split()` because some paths may have `/` characters in elements.

## Type of change

<!--- Please check the type of change your PR introduces: --->
- [x] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Test
- [ ] 💻 CI/Deployment
- [ ] 🐹 Trivial/Minor

## Issue(s)

* closes #909 

## Test Plan

<!-- How will this be tested prior to merging.-->
- [ ] 💪 Manual
- [x] ⚡ Unit test
- [ ] 💚 E2E

src/internal/connector/onedrive/restore.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"strings"
 
 	"github.com/pkg/errors"
 
@@ -35,7 +34,7 @@ type drivePath struct {
 }
 
 func toOneDrivePath(p path.Path) (*drivePath, error) {
-	folders := strings.Split(p.Folder(), "/")
+	folders := p.Folders()
 
 	// Must be at least `drives/<driveID>/root:`
 	if len(folders) < 3 {

src/internal/path/path.go

@@ -70,6 +70,7 @@ type Path interface {
 	Tenant() string
 	ResourceOwner() string
 	Folder() string
+	Folders() []string
 	Item() string
 	// PopFront returns a Builder object with the first element (left-side)
 	// removed. As the resulting set of elements is no longer a valid resource

src/internal/path/resource_path.go

@@ -141,20 +141,37 @@ func (rp dataLayerResourcePath) ResourceOwner() string {
 	return rp.Builder.elements[2]
 }
 
-// Folder returns the folder segment embedded in the dataLayerResourcePath.
-func (rp dataLayerResourcePath) Folder() string {
+func (rp dataLayerResourcePath) lastFolderIdx() int {
 	endIdx := len(rp.Builder.elements)
-	if endIdx == 4 {
-		return ""
-	}
 
 	if rp.hasItem {
 		endIdx--
 	}
 
+	return endIdx
+}
+
+// Folder returns the folder segment embedded in the dataLayerResourcePath.
+func (rp dataLayerResourcePath) Folder() string {
+	endIdx := rp.lastFolderIdx()
+	if endIdx == 4 {
+		return ""
+	}
+
 	return rp.Builder.join(4, endIdx)
 }
 
+// Folders returns the individual folder elements embedded in the
+// dataLayerResourcePath.
+func (rp dataLayerResourcePath) Folders() []string {
+	endIdx := rp.lastFolderIdx()
+	if endIdx == 4 {
+		return nil
+	}
+
+	return append([]string{}, rp.elements[4:endIdx]...)
+}
+
 // Item returns the item embedded in the dataLayerResourcePath if the path
 // refers to an item.
 func (rp dataLayerResourcePath) Item() string {

src/internal/path/resource_path_test.go

@@ -49,22 +49,22 @@ var (
 	}
 
 	modes = []struct {
-		name           string
-		isItem         bool
-		expectedFolder string
-		expectedItem   string
+		name            string
+		isItem          bool
+		expectedFolders []string
+		expectedItem    string
 	}{
 		{
-			name:           "Folder",
-			isItem:         false,
-			expectedFolder: strings.Join(rest, "/"),
-			expectedItem:   "",
+			name:            "Folder",
+			isItem:          false,
+			expectedFolders: rest,
+			expectedItem:    "",
 		},
 		{
-			name:           "Item",
-			isItem:         true,
-			expectedFolder: strings.Join(rest[0:len(rest)-1], "/"),
-			expectedItem:   rest[len(rest)-1],
+			name:            "Item",
+			isItem:          true,
+			expectedFolders: rest[:len(rest)-1],
+			expectedItem:    rest[len(rest)-1],
 		},
 	}
 
@@ -152,6 +152,7 @@ func (suite *DataLayerResourcePath) TestMailItemNoFolder() {
 			require.NoError(t, err)
 
 			assert.Empty(t, p.Folder())
+			assert.Empty(t, p.Folders())
 			assert.Equal(t, item, p.Item())
 		})
 	}
@@ -206,6 +207,7 @@ func (suite *DataLayerResourcePath) TestDir() {
 
 					expected := path.Builder{}.Append(elements...).Append(rest[:len(rest)-i]...)
 					assert.Equal(t, expected.String(), p.String())
+					assert.Empty(t, p.Item())
 				})
 			}
 
@@ -266,7 +268,8 @@ func (suite *DataLayerResourcePath) TestToExchangePathForCategory() {
 					assert.Equal(t, path.ExchangeService, p.Service())
 					assert.Equal(t, test.category, p.Category())
 					assert.Equal(t, testUser, p.ResourceOwner())
-					assert.Equal(t, m.expectedFolder, p.Folder())
+					assert.Equal(t, strings.Join(m.expectedFolders, "/"), p.Folder())
+					assert.Equal(t, m.expectedFolders, p.Folders())
 					assert.Equal(t, m.expectedItem, p.Item())
 				})
 			}
@@ -336,7 +339,19 @@ func (suite *PopulatedDataLayerResourcePath) TestResourceOwner() {
 func (suite *PopulatedDataLayerResourcePath) TestFolder() {
 	for _, m := range modes {
 		suite.T().Run(m.name, func(t *testing.T) {
-			assert.Equal(t, m.expectedFolder, suite.paths[m.isItem].Folder())
+			assert.Equal(
+				t,
+				strings.Join(m.expectedFolders, "/"),
+				suite.paths[m.isItem].Folder(),
+			)
+		})
+	}
+}
+
+func (suite *PopulatedDataLayerResourcePath) TestFolders() {
+	for _, m := range modes {
+		suite.T().Run(m.name, func(t *testing.T) {
+			assert.Equal(t, m.expectedFolders, suite.paths[m.isItem].Folders())
 		})
 	}
 }