[Feature] Support client level header/path apiVersion

[v-jiaodi]

Summary

The TypeSpec TypeScript generator for Azure Modular SDK incorrectly generates code that imports version from Node.js os module instead of using the client's API version string, causing TypeScript compilation errors.

Spector case link: https://github.com/Azure/typespec-azure/tree/main/packages/azure-http-specs/specs/azure/client-generator-core/api-version

Bug Details

• Component: TypeSpec TypeScript Generator (Modular SDK)
• Error Type: Incorrect import generation
• Affected Files: *Context.ts files in generated Modular SDK clients
• TypeScript Error: Type '() => string' is not comparable to type 'string'

Generated Code Issue

The generator produces incorrect code like this:

// ❌ INCORRECT - Generated by TypeSpec generator
import { version } from "os";  // This imports Node.js os.version() function
import { logger } from "../logger.js";
import { Client, ClientOptions, getClient } from "@azure-rest/core-client";

export function createHeader(options: HeaderClientOptionalParams = {}): HeaderContext {
  // ... other code ...
  clientContext.pipeline.addPolicy({
    name: "ClientApiVersionPolicy",
    sendRequest: (req, next) => {
      // ... 
      req.url = `${req.url}api-version=${version}`;  // ❌ version is a function, not string
      // ...
    },
  });
  return { ...clientContext, version } as HeaderContext;  // ❌ Type error here
}

[MaryGao]

@v-jiaodi Could you link the relevant spector case link?

[v-jiaodi]

@v-jiaodi Could you link the relevant spector case link?

https://github.com/Azure/typespec-azure/tree/main/packages/azure-http-specs/specs/azure/client-generator-core/api-version

[qiaozha]

This is pending tcgc fix Azure/typespec-azure#2947