fix: return types and optional chaining in field masks when useOptionals=all

integration/fieldmask-optional-all/fieldmask-optional.proto

@@ -0,0 +1,7 @@
+syntax = "proto3";
+
+import "google/protobuf/field_mask.proto";
+
+message Example {
+  google.protobuf.FieldMask mask = 1;
+}

integration/fieldmask-optional-all/fieldmask-optional.ts

@@ -0,0 +1,82 @@
+/* eslint-disable */
+import * as _m0 from "protobufjs/minimal";
+import { FieldMask } from "./google/protobuf/field_mask";
+
+export const protobufPackage = "";
+
+export interface Example {
+  mask?: string[] | undefined;
+}
+
+function createBaseExample(): Example {
+  return { mask: undefined };
+}
+
+export const Example = {
+  encode(message: Example, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    if (message.mask !== undefined) {
+      FieldMask.encode(FieldMask.wrap(message.mask), writer.uint32(10).fork()).ldelim();
+    }
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): Example {
+    const reader = input instanceof _m0.Reader ? input : _m0.Reader.create(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseExample();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          if (tag !== 10) {
+            break;
+          }
+
+          message.mask = FieldMask.unwrap(FieldMask.decode(reader, reader.uint32()));
+          continue;
+      }
+      if ((tag & 7) === 4 || tag === 0) {
+        break;
+      }
+      reader.skipType(tag & 7);
+    }
+    return message;
+  },
+
+  fromJSON(object: any): Example {
+    return { mask: isSet(object.mask) ? FieldMask.unwrap(FieldMask.fromJSON(object.mask)) : undefined };
+  },
+
+  toJSON(message: Example): unknown {
+    const obj: any = {};
+    if (message.mask !== undefined) {
+      obj.mask = FieldMask.toJSON(FieldMask.wrap(message.mask));
+    }
+    return obj;
+  },
+
+  create<I extends Exact<DeepPartial<Example>, I>>(base?: I): Example {
+    return Example.fromPartial(base ?? ({} as any));
+  },
+  fromPartial<I extends Exact<DeepPartial<Example>, I>>(object: I): Example {
+    const message = createBaseExample();
+    message.mask = object.mask ?? undefined;
+    return message;
+  },
+};
+
+type Builtin = Date | Function | Uint8Array | string | number | boolean | undefined;
+
+export type DeepPartial<T> = T extends Builtin ? T
+  : T extends globalThis.Array<infer U> ? globalThis.Array<DeepPartial<U>>
+  : T extends ReadonlyArray<infer U> ? ReadonlyArray<DeepPartial<U>>
+  : T extends {} ? { [K in keyof T]?: DeepPartial<T[K]> }
+  : Partial<T>;
+
+type KeysOfUnion<T> = T extends T ? keyof T : never;
+export type Exact<P, I extends P> = P extends Builtin ? P
+  : P & { [K in keyof P]: Exact<P[K], I[K]> } & { [K in Exclude<keyof I, KeysOfUnion<P>>]: never };
+
+function isSet(value: any): boolean {
+  return value !== null && value !== undefined;
+}

integration/fieldmask-optional-all/fieldmask-test.ts

@@ -0,0 +1,59 @@
+import { Example } from "./fieldmask-optional";
+
+let data = {
+  mask: "a,b,c.d",
+};
+
+describe("fieldmask-optional-all", () => {
+  it("can decode canonical JSON", () => {
+    const f = Example.fromJSON(data);
+    expect(f).toMatchInlineSnapshot(`
+      {
+        "mask": [
+          "a",
+          "b",
+          "c.d",
+        ],
+      }
+    `);
+  });
+
+  it("can decode non-canonical JSON", () => {
+    const f = Example.fromJSON({
+      mask: {
+        paths: ["a", "b", "c.d"],
+      },
+    });
+    expect(f).toMatchInlineSnapshot(`
+      {
+        "mask": [
+          "a",
+          "b",
+          "c.d",
+        ],
+      }
+    `);
+  });
+
+  it("can encode JSON", () => {
+    const f = Example.toJSON({ mask: ["a", "b", "c.d"] });
+    expect(f).toEqual(data);
+  });
+
+  it("can encode JSON with undefined input", () => {
+    const f = Example.toJSON({ mask: undefined });
+    expect(f).toEqual({ mask: undefined });
+  });
+
+  it("skips empty paths", () => {
+    const f = Example.fromJSON({ mask: "a,,c.d" });
+    expect(f).toMatchInlineSnapshot(`
+      {
+        "mask": [
+          "a",
+          "c.d",
+        ],
+      }
+    `);
+  });
+});