[tcgc] How to generate code with nested properties mappings between sdk method and sdk operation parameters?

[MaryGao]

This is a case we met recently and for template ArmResourceActionAsync its second parameter is marked as bodyRoot.

With below case1 we have required body parameter which is marked as @bodyRoot and also two optional parameters which is marked as @body and @query. In tcgc it would give one method parameter with body. And for operation parameters its correspondingMethodParams would not directly link to top-level body but its properties bodyParam and queryParam.

I have following things to confirm:

• How should we interprect @bodyRoot here?
• Can we(emitter) just take@bodyRoot as a wrapper object and won't impact the method signiture?
• So case 1 and case 2 are the same? If so, can tcgc produce the same codemodel?
• Does the parameter order matter?

Case1

op read(@bodyRoot body: {
  @body bodyParam?: string;
  @query queryParam?: string;
}): void;

Case2

op read(@body bodyParam?: string, @query queryParam?: string;): void;

Case3

op read(bodyParam?: string, @query queryParam?: string;): void;

Case4

op read(@bodyRoot body: {
  bodyParam1?: string;
  bodyParam2?: string;
  @query queryParam?: string;
}): void;

[qiaozha]

Is this duplicate with this one microsoft/typespec#4815 ?