Seperate documentation lookup from find field type

Author: jnthntatum

cel/fieldpaths.go

@@ -22,6 +22,12 @@ func (f *fieldPath) Documentation() *common.Doc {
 	return common.NewFieldDoc(f.path, f.celType.String(), f.description)
 }
 
+type documentationProvider interface {
+	// FindStructFieldDescription returns documentation for a field if available.
+	// Returns false if the field could not be found.
+	FindStructFieldDescription(typeName, fieldName string) (string, bool)
+}
+
 type backtrack struct {
 	// provider used to resolve types.
 	provider types.Provider
@@ -79,10 +85,14 @@ func (b *backtrack) expandFieldPaths(celType *Type, paths []*fieldPath) []*field
 				continue
 			}
 			b.push(field, celType)
+			description := ""
+			if docProvider, ok := b.provider.(documentationProvider); ok {
+				description, _ = docProvider.FindStructFieldDescription(celType.String(), field)
+			}
 			path := &fieldPath{
 				celType:     fieldType.Type,
 				path:        formatPath(b.path),
-				description: fieldType.Description,
+				description: description,
 				isLeaf:      false,
 			}
 			paths = append(paths, path)

common/types/provider.go

@@ -81,9 +81,6 @@ type FieldType struct {
 
 	// GetFrom retrieves the field value on the input object, if set.
 	GetFrom ref.FieldGetter
-
-	// Description provides a description of the field. Empty if no description available.
-	Description string
 }
 
 // Registry provides type information for a set of registered types.
@@ -209,13 +206,26 @@ func (p *Registry) FindStructFieldType(structType, fieldName string) (*FieldType
 		return nil, false
 	}
 	return &FieldType{
-		Type:        fieldDescToCELType(field),
-		IsSet:       field.IsSet,
-		GetFrom:     field.GetFrom,
-		Description: field.Documentation(),
+		Type:    fieldDescToCELType(field),
+		IsSet:   field.IsSet,
+		GetFrom: field.GetFrom,
 	}, true
 }
 
+// FindStructFieldDescription returns documentation for a field if available.
+// Returns false if the field could not be found.
+func (p *Registry) FindStructFieldDescription(structType, fieldName string) (string, bool) {
+	msgType, found := p.pbdb.DescribeType(structType)
+	if !found {
+		return "", false
+	}
+	field, found := msgType.FieldByName(fieldName)
+	if !found {
+		return "", false
+	}
+	return field.Documentation(), true
+}
+
 // FindIdent takes a qualified identifier name and returns a ref.Val if one exists.
 func (p *Registry) FindIdent(identName string) (ref.Val, bool) {
 	if t, found := p.revTypeMap[identName]; found {