feat: Update fromPartial and fromJson to respect initializeFieldsAsUndefined

integration/from-partial-no-initialize/parameters.txt

@@ -0,0 +1 @@
+useOptionals=all,initializeFieldsAsUndefined=false

integration/from-partial-no-initialize/partials-test.ts

@@ -0,0 +1,50 @@
+import { TPartial } from './test'
+
+describe('partials-test', () => {
+  it('works with singular fields', () => {
+    const test = {
+      number: 2,
+      string: 'hi',
+      message: {
+        field: 'hello'
+      }
+    };
+
+    const result = TPartial.fromPartial(test);
+
+    expect(result).toEqual(test);
+  });
+
+  it('works with repeated fields', () => {
+    const test = {
+      map: {
+        a: 'b',
+        c: 'd'
+      },
+
+      repeatedMessage: [
+        {
+          field: 'world'
+        },
+        {
+          field: 'hello'
+        }
+      ],
+
+      repeatedString: [
+        'goodbye',
+        'world'
+      ],
+
+      repeatedNumber: [
+        1,
+        2,
+        3
+      ]
+    };
+
+    const result = TPartial.fromPartial(test);
+
+    expect(result).toEqual(test);
+  });
+})

integration/from-partial-no-initialize/test.proto

@@ -0,0 +1,15 @@
+syntax = "proto2";
+
+message TPartialMessage{
+  required string field = 1;
+}
+
+message TPartial{
+  optional int32 number = 1;
+  optional string string = 2;
+  map<string, string> map = 3;
+  optional TPartialMessage message = 4;
+  repeated TPartialMessage repeated_message = 5;
+  repeated string repeated_string = 6;
+  repeated int32 repeated_number = 7;
+}