[azcore] Add text [un]marshalling support to ResourceID (Azure#23381)

Co-authored-by: Matthew Barnes <[email protected]>

Author: mbarnes

sdk/azcore/CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Features Added
 
 * Added field `OperationLocationResultPath` to `runtime.NewPollerOptions[T]` for LROs that use the `Operation-Location` pattern.
+* Support `encoding.TextMarshaler` and `encoding.TextUnmarshaler` interfaces in `arm.ResourceID`.
 
 ### Breaking Changes
 

sdk/azcore/arm/internal/resource/resource_identifier.go

@@ -110,6 +110,21 @@ func (id *ResourceID) String() string {
 	return id.stringValue
 }
 
+// MarshalText returns a textual representation of the ResourceID
+func (id *ResourceID) MarshalText() ([]byte, error) {
+	return []byte(id.String()), nil
+}
+
+// UnmarshalText decodes the textual representation of a ResourceID
+func (id *ResourceID) UnmarshalText(text []byte) error {
+	newId, err := ParseResourceID(string(text))
+	if err != nil {
+		return err
+	}
+	*id = *newId
+	return nil
+}
+
 func newResourceID(parent *ResourceID, resourceTypeName string, resourceName string) *ResourceID {
 	id := &ResourceID{}
 	id.init(parent, chooseResourceType(resourceTypeName, parent), resourceName, true)

sdk/azcore/arm/internal/resource/resource_identifier_test.go

@@ -6,7 +6,10 @@
 
 package resource
 
-import "testing"
+import (
+	"encoding"
+	"testing"
+)
 
 func TestParseResourceIdentifier(t *testing.T) {
 	testData := map[string]*ResourceID{
@@ -220,6 +223,26 @@ func TestParseResourceIdentifier(t *testing.T) {
 	}
 }
 
+// Ensure ResourceID implements these interfaces
+var _ encoding.TextMarshaler = (*ResourceID)(nil)
+var _ encoding.TextUnmarshaler = (*ResourceID)(nil)
+
+func TestMarshalResourceIdentifier(t *testing.T) {
+	resourceID := &ResourceID{}
+	input := []byte("/subscriptions/17fecd63-33d8-4e43-ac6f-0aafa111b38d/resourceGroups/myRg/providers/Microsoft.ApiManagement/service/myServiceName/subscriptions/mySubs")
+	err := resourceID.UnmarshalText(input)
+	if err != nil {
+		t.Fatalf("unexpected error: %+v", err)
+	}
+	output, err := resourceID.MarshalText()
+	if err != nil {
+		t.Fatalf("unexpected error: %+v", err)
+	}
+	if string(output) != string(input) {
+		t.Fatalf("resource id changed, got %v, expected %v", string(output), string(input))
+	}
+}
+
 func equals(left, right *ResourceID) bool {
 	if left != nil && right != nil {
 		if left.String() != right.String() {