feat(fieldpath): Handle case differences in structure member names

pkg/fieldpath/path.go

@@ -242,7 +242,17 @@ func memberShapeRef(
 	}
 	switch shapeRef.Shape.Type {
 	case "structure":
-		return shapeRef.Shape.MemberRefs[memberName]
+		// We are looking for a member of a structure. Since the ACK fields and
+		// the AWS SDK fields may have different casing (e.g AWSVPCConfiguration
+		// and AwsVpcConfiguration) we need to perform a case insensitive
+		// comparison to find the correct member reference.
+		for memberRefName, memberRefShape := range shapeRef.Shape.MemberRefs {
+			if strings.EqualFold(memberRefName, memberName) {
+				return memberRefShape
+			}
+		}
+		// If no matching member is found, return nil.
+		return nil
 	case "list":
 		return memberShapeRef(&shapeRef.Shape.MemberRef, memberName)
 	case "map":

pkg/fieldpath/path_test.go

@@ -148,6 +148,12 @@ func TestShapeRef(t *testing.T) {
 						},
 					},
 				},
+				"WeirdlycasEdType": &awssdkmodel.ShapeRef{
+					ShapeName: "WeirdlycasEdType",
+					Shape: &awssdkmodel.Shape{
+						Type: "string",
+					},
+				},
 			},
 		},
 	}
@@ -220,4 +226,11 @@ func TestShapeRef(t *testing.T) {
 
 	// Calling ShapeRef should not modify the original Path
 	require.Equal("Author.Books.ChapterPageCounts.PageCount", p.String())
+
+	// Case-insensitive comparisons...
+	p = fieldpath.FromString("Author.WeirdlyCasedType")
+	ref = p.ShapeRef(authShapeRef)
+	require.NotNil(ref)
+	require.Equal("WeirdlycasEdType", ref.ShapeName)
+	require.Equal("string", ref.Shape.Type)
 }