fix: Struct wrap/unwrap snake case #579 (#588)

* fix: Struct wrap/unwrap snake case #579

* test: Add more tests about struct snake case

* style: format src/main.ts

Co-authored-by: TJT <tjt@maimemo.com>

integration/oneof-unions-snake/parameters.txt

@@ -0,0 +1 @@
+snakeToCamel=false,oneof=unions

integration/oneof-unions-snake/simple-snake-test.ts

@@ -0,0 +1,12 @@
+import { SimpleStruct  } from './simple';
+
+describe('oneof=unions,snakeToCamel=false', () => {
+  it('struct snake case', () => {
+    const simple: SimpleStruct = {
+      simple_struct: {
+        any: 'any'
+      }
+    }
+    expect(simple.simple_struct!['any']).toEqual('any')
+  })
+});

integration/oneof-unions-snake/simple.proto

@@ -0,0 +1,9 @@
+// Adding a comment to the syntax will become the first
+// comment in the output source file.
+syntax = "proto3";
+import "google/protobuf/struct.proto";
+package simple;
+
+message SimpleStruct {
+  google.protobuf.Struct simple_struct = 1;
+}

integration/oneof-unions-snake/simple.ts

@@ -0,0 +1,94 @@
+/* eslint-disable */
+import * as Long from 'long';
+import * as _m0 from 'protobufjs/minimal';
+import { Struct } from './google/protobuf/struct';
+
+export const protobufPackage = 'simple';
+
+/**
+ * Adding a comment to the syntax will become the first
+ * comment in the output source file.
+ */
+
+export interface SimpleStruct {
+  simple_struct: { [key: string]: any } | undefined;
+}
+
+function createBaseSimpleStruct(): SimpleStruct {
+  return { simple_struct: undefined };
+}
+
+export const SimpleStruct = {
+  encode(message: SimpleStruct, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    if (message.simple_struct !== undefined) {
+      Struct.encode(Struct.wrap(message.simple_struct), writer.uint32(10).fork()).ldelim();
+    }
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): SimpleStruct {
+    const reader = input instanceof _m0.Reader ? input : new _m0.Reader(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseSimpleStruct();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          message.simple_struct = Struct.unwrap(Struct.decode(reader, reader.uint32()));
+          break;
+        default:
+          reader.skipType(tag & 7);
+          break;
+      }
+    }
+    return message;
+  },
+
+  fromJSON(object: any): SimpleStruct {
+    return {
+      simple_struct: isObject(object.simple_struct) ? object.simple_struct : undefined,
+    };
+  },
+
+  toJSON(message: SimpleStruct): unknown {
+    const obj: any = {};
+    message.simple_struct !== undefined && (obj.simple_struct = message.simple_struct);
+    return obj;
+  },
+
+  fromPartial<I extends Exact<DeepPartial<SimpleStruct>, I>>(object: I): SimpleStruct {
+    const message = createBaseSimpleStruct();
+    message.simple_struct = object.simple_struct ?? undefined;
+    return message;
+  },
+};
+
+type Builtin = Date | Function | Uint8Array | string | number | boolean | undefined;
+
+export type DeepPartial<T> = T extends Builtin
+  ? T
+  : T extends Array<infer U>
+  ? Array<DeepPartial<U>>
+  : T extends ReadonlyArray<infer U>
+  ? ReadonlyArray<DeepPartial<U>>
+  : T extends { $case: string }
+  ? { [K in keyof Omit<T, '$case'>]?: DeepPartial<T[K]> } & { $case: T['$case'] }
+  : 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]> } & Record<Exclude<keyof I, KeysOfUnion<P>>, never>;
+
+// If you get a compile-error about 'Constructor<Long> and ... have no overlap',
+// add '--ts_proto_opt=esModuleInterop=true' as a flag when calling 'protoc'.
+if (_m0.util.Long !== Long) {
+  _m0.util.Long = Long as any;
+  _m0.configure();
+}
+
+function isObject(value: any): boolean {
+  return typeof value === 'object' && value !== null;
+}